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1. i i i L i i i i i i i m dm momo m mc mmm i i i i i L i i i i i i L i 1 commos n n i V t 1 i 1 L i i i i i 1 i 1 i 1 1 i i i i i i L i i i ommo om mom cmo je m m i i i i i 1 i 1 m mmm ee i 1 i 1 1 i i i 1 l L 1 i T lcu ec i i 1 i i i 1 i I i i i i L i 1 I SSeS 4 cm OM SAC 1 i 1 i i 1 i i I i i 1 1 see ee pee 1 i 1 1 L 1 i LI 1 i 1 1 L 000 0 300 0 01070 8100 02070 4200 0500 85070 0700 Spo 0 080 0 Output V Fig 5 Characteristic Graph II of Detector 82 180g 0 8 9 7 2 0 2 Bw 9 8 Ql Zl tl 91 81 02 ZZ pZ 92 82 0 lt i 1 i i i i i i i 1 I i i i i i Lai i i i i 1 i i i i 1 1 i 1 L i 1 i 1 i n i i i 1 0 i i i i i i i 1 i i ps Pea SF Pea ee Pee Se mom com mom je j
2. 0 00059 0 125 0 00074 0 149 0 00121 0 176 0 00180 0 239 0 00238 0 276 00097 BEEF NEN 0 00372 0 35 29 0081 is 0000 Lm eee as O08 2 0003 Tau ae 10321021 420 003 12 n o 90075 a 127 8 oww 80 9 8 1 gl ftl 9l 81 0c c to 9c Be 05 Fun 1 i gt 018 9 g 1 1 1 1 1 1 i i i 1 i 1 i a 1 1 1 1 i I i 1 1 i 1 i i 1 i 1 4 1 1 L dom aom omo A d m mue modom ej e H 1 1 1 i 1 1 i 1 1 i i 1 i i 1 i i i 1 1 1 i i 1 i 1 V 1 i i i i i i i i 1 1 i 1 bade bode el eh ok 4 als b ds sbl l er i i 1 i 1 1 1 i ii 1 1 i 1 i i i 1 1 i i 1 i i L i i 1 i i i i i 1 1 i i i i i i i i I i 1 i i
3. INSTRUMENTS AT RF3030 RF EDUCATION EXPERIMENT SYSTEM Manual For Experiment SHENZHEN ATTEN ELECTRONICS CO LTD Quality assurance SHENZHEN ATTEN ELECTRONICS Co Ltd offers the quality assurance for this product Considerations for quality assurance Assurance contents We guarantee 2 year after service from the date of purchasing this product If this product has any troubles or errors within such a period you can receive free service from ATTEN customer support center Expenses covered by customers The necessary services shall be offered at a minimum cost of customers in the following cases 1 If the warranty period expires However it shall be valid for 5 years after the warranty period expires 2 If the product has any troubles due to customers negligence or Act of God gt lt They shall be handled at a charge of customers even during the warranty period Not guaranteed Any deliberate disassembly of this product for improving the performance cannot be covered by the manufacturer s warranty responsibility Service guide Please contact our customer support center for service application and consultation Customer support center 86 755 8602 1376 Fax 86 755 8602 1347 gt For the safe and correct use of this product please make sure to read the user s manual carefully before using it and follow the guidelines on how to handle and use this product Notice for equipment changes This product
4. iri Jas con Tamp Tram Ae in ie A mu m pece ununi Soo RBIAS 1 Resistor Values ohms for Optimum Biasing of ERA Models ERA ERA 2 ERA 215M ERA 3 ERA 335M ERA 4 ERA 5 ERA 505M typical biasing configuration ERA 15M ERA 25M ERA 35M A4SMAXSM 55M 515M SXSM ERA 6SM 1 909 88 7 107 38 3 33 2 40 2 30 1 8 113 113 113 133 11 32 1 48 7 43 2 9 137 137 131 152 115 88 5 83 4 651 58 2 ORIENTATION DOT 10 162 162 162 181 14 805 78 7 825 BUE N 11 1 7 187 181 22 155 85 3 95 3 814 44 5 12 215 215 215 249 191 110 110 113 87 5 no 1 13 237 231 237 260 215 127 124 127 113 14 251 281 281 ane 243 143 140 143 127 15 287 7 287 340 281 158 158 158 140 18 100 30g 316 165 287 114 174 174 154 17 112 332 340 202 318 187 1 191 180 18 357 365 422 34 205 205 205 182 14 181 382 392 453 385 221 221 27 196 A 412 412 412 475 302 237 212 237 210 ERA 85M 88 7 11 183 174 200 226 255 280 301 340 335 32 422 453 MTTF vs Junction Temp ERA 5 58 1 NSN GUIDE pin connections MCLNO POR ERA 15M 5962 01 459 9075 RF IN ERA 35M 5906 01 516 5438 RF OUT a 45 5962 01 459 7410 DC 55 3u52 01 458 3314 CASE GND NOT USED DEMO BOARD 140 160 180 200 220 Junction T
5. ip oom om mov om mmm um je mo m c po 4 4 me ommo eom pomo omo pm com om m pm m ge ges omo oco om jum c o mj m mom i i i 1 il i i i i i i 1 1 i i i i 4 1 i 1 i i i i I i i i i i i 1 i i i i i i i i i i i i i i 4 1 4 1 i i i i ce 81 Outnput V Fig 4 Characteristic Graph 1 of Detector o CC cC om uh Gm E II LI LL L ela mom a L i 1 m eje oom m o a odes m m Pm m m d mm um mom me Ro a a LI o ese me mee mm m Lil bur i a a E R riii ids Li LI i i m ub dm d GR eS mm o m 4 SS 31 61 05 12 ZZ Z 2 97 12 82 6z 00 L
6. om mm mom ouam mom mm 4 L i D i i i L 1 i I i i 1 i i i i i i i i i i i i i 1 I 1 i i 1 i I 1 1 i i i i i 1 I i i i i i i i i TELEL EITE ee ee ee NTETE ee Lomo 4 mmm be i 1 li 1 i 1 1 i 1 4 i i i 1 1 i 1 i i a i i i i i 1 il 1 l 1 1 4 1 19 1 i i i i i 1 1 i i I i i 1 i 115 ew AN A EM M MEME EE NE d ETE i i 1 i i i 1 i i i 1 i i 1 i i i i 7 1 i 1 i i i 12 711 d V d 1 WV 13 ee ey i i i i i 1 i i i 1 i i i i i i 1 i i 1 i i i i i i L i 1 i i i i i i i i 1 i i i i i i I i i i i i i i i i eT ee ease 1 l 1 L i i i 1 i i i i I i i i i i i i i i i i i 1 i i i i il 1 i i i i i i i H i i 1 2 4 om om eb oboe eis gd 4 sk ed m od le eh be eee 4 amp amp 1 L i 1 1 l i i 1 i i i i i i 1 i i i i 1 1 1
7. 1 1 1 i i 1 i i i i i i 1 1 1 i i 4 1 i i 4 i MJ SA E Y 8 id 14 1 4 Y rF 73 C T7 FO n 1 1 I I 1 i i i i i 1 1 I 1 I 1 L i 1 1 i 1 i i i i 1 i i i E 1 i epum eee a eee ee ee eee ae see I i 1 1 i i i i i i i i i 4 i i i 1 E i 1 1 1 1 1 1 i i 1 1 i 1 1 I i i i i i s J b l d l ei 4 og o o d do so 4 4 4 mum n oL 4 x b hom 1 i 1 i 1 i i i i i i i i i i i i 1 i i i 1 i 4 1 1 1 1 1 1 1 1 i i 1 I i L LI LI LI a ee ee 5 2 08 8 gt 82 2 0 6 4 20 12221 2 2 2142 2822 ho deck ec 1 1 1 1 1 1 i 1 1 1 I 1 1 i i i 4 i 1 1 i 1 1 1 i I
8. 1 F 4 1 1 3 f 25 Circumference c Stub Resonator b Open end Resonator a Ring Resonator Fig 11 4 Various Microstrip Resonators The resonance occurs in the following conditions For the ring resonator 2mr n g n 1 2 3 For the open end H f 1 2 3 For the open stub n 1 2 3 Here the wavelength is 3 10 em 3 aff Because the ring resonator has no open end and almost no radiation loss it has an advantage of being able to measure more accurately than the open end or open stub resonator Because the dielectric resonator shown in Fig 11 5 is used with the microstrip line and manufactured to have quite a large relative dielectric constant of 30 50 it can be made smaller than the microstrip resonator Fig 11 4 The resonance frequency of the dielectric resonator is xo HA 3445 6 r Microstrip Line Fig 11 5 Dielectric Resonator For the reference Q value of the microstrip resonator is less than 200 that of the dielectric resonator 15 about 1000 and that of the waveguide resonator 15 a few thousands 54 Measuring Instruments Module Name AT6030D Spectrum Analyzer tracking generator AT RF3030 16 5 5 IV Experimental Procedures 1 First adjust the frequency of the AT6030D f Z1500MHz SPAN 3000MHz Con
9. Min dB dB W L W H x x rdi Fig 2 7 Specification of Circulator Measuring instruments Module Name Spectrum Analyzer tracking generator 5 5 IV Experimental Procedures 1 Connect all the lines to form a circuit as shown in Fig 2 8 Connect 50 9 Load to port 3 P3 in order to use the AT RF3030 3 Circulator as an Isolator 2 Adjust the frequency of the AT6030D in fp 1500MHz Span 3000MHZz observing the frequency with AT6030D measuring the inserted L lt 3dB or not when f 1800 2200MHz 3 Connect port 2 and port 3 of the AT RF3030 3 Circulator module Measure the inserted loss L215 dB of port when f 1800 2200MHZz that is isolation of port 3 to port 1 4 Because the ports of AT RF3030 3 Circulator module are different from each other so measure the inserted loss in port 3 port 1 and measure the isolation from port 1 port 2 when input from port 2 port 3 Inserted loss and isolation must meet the Parameters above V Review 1 Examine the types of ferrite and list the microwave circuits using the irreversibility of ferrite 2 Explain the principle of an isolator for the waveguide 3 How would the result change if 50 9 Load is not connected to P3 terminal or the SMA Short is connected 3 Theory and Experiment of Directional Coupler I Objective To comprehend the purpose and operational principle of the coupler by using the AT RF3030 4 Directional Coupler modu
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11. 1 i L ii 1 i i i i i i i i i i i P i i i i i i i i i I 771 Wo 1 4 1 X4 a 2 I 1 L 1 i 1 i i i i ii i i i i i i i i 1 i i i i i 1 i i 1 1 I i i i i i E i I i ii i i i i i i i i i i ii i i ees mmc om momo qe qom m ee poop i i i i i i i i i i i i i 1 1 i i i i i 1 i i 1 i i i i i 1 1 1 L i i hom dom hle l ol a ma a a l jl l ee mcm e m jm mom momo i L I i i 4 i i i i i i 1 i i 1 1 i i i i i i i i 1 I i i i i i i i i i i i i i 1 i ii i i i i i i i i a I es Se 5 1 L nee ml m mia mb uon cem am om emm ee
12. 1 i i 1 1 i 1 i 1 i i i i i 1 i 1 1 L LI i i i i i i i i i i 1 i a i 1 i i i i T r 3 w T4 wv 7771776073797 794737 771 34 1784776717707 T7 776 770 758777777 04 1 i i 1 1 i 1 i 1 1 1 i i 8 i i i 1 i i 1 1 E 1 i i 1 l i i 4 4 a i i i i i imm om Rom d IL t k 4 i i 1 i 1 1 i i i i 1 i 4 i i i i L i 1 i i 1 i i 1 i 1 1 i 4 i i i 1 i i 4 i i 1 1 4 1 om oom ech ete ele _ Le 1 _ _ eh Led ome ox ele m 1 1 1 i 1 i 1 i i i i i i i 1 1 1 i 1 1 1 i i 1 1 1 1 i i 1 i i i i i i i i i i i i i i i i i i i 1 4 E lh eel aap eel ee eel i i i i i i i i i i i L i i 1 i i i i 1 1 i i i i i i 1 i i i i i i i i i i 1 1
13. Fe m d Aust Pot 3 Port 2 127 Electric Magnetic Field Resonance Pattern IT 1 held Ez Electric 2 22 Fia xS Ere CES a 7 4 QUO e 2 37 i J 1 l art 3 127 amp qam 24 isa aled oulpul b 30 Rotation Electric Field Magnetic Field Resonance Pattern Fig 2 6 Operating Principle of Electric Magnetic Resonance Pattern Circulator When a DC magnetic system perpendicular to the ferrite disk is applied the input plane moves about 30 a counterclockwise direction so that the same signal as that applied at port 2 1s detected at port 2 However port 3 18 placed at an intersection between and polarities of the electric system that is a null point so that the electric system can not form and no signals are detected at port 3 Even if port 2 and port 3 are used as the input ports the power is detected only at one port as described above and it is isolated at the other ports which plays a role as a circulator In addition to the above stripline type of circulator a microstrip or waveguide type circuit can form a circulator Moreover it can be applied in various ways by changing the shape of the middle metal plate in order to reduce the size of the entire circuit Fig 2 7 shows a specification of an element used in the circulator module 1940 1 14 5 2 6 2 19 0 1 13 Isolation is VSWR CW power Sizeinch
14. i E i i L a i 1 i i i i i 1 ii i L n ee eee a a ee ee ese er er a eae ese ee Pee i 1 i i i 1 i i i i i 1 i i i I i i 1 i i i i 1 i 1 1 i i i i i i 1 i 4 I 1 i 4 i 1 i i i 1 i i om ad m me bm mim ET ee ee xL o L 1 i i i i i 1 1 I 1 1 i 1 i 1 i Li L l L L L i i L i i i 1 1 1 1 i i i i 1 l 1 i 1 o di l L J L 4 LR d4 L J lul L 0 4434 L 10 0 L LI 1 L 1 1 i 1 i i i i i L i i i i i i i 1 1 L 1 i 1 i I i i 1 i i i i i i i i i i i i i i i i i i i i 1 i i i i i i i i i i L i i i i i i i i i i I i i i i CE ee ee ee eae Pe a ae ae es a e aa ae 1 1 l i i i i L 1 L i i i i i i 1 i i a i i i 1 1 1 i 1 1 i i i i i i i i i 1 1 sre ae geom m omm modom
15. I Objective To comprehend the operational principle and purpose of Branch Line Coupler using AT RF3030 20 Branch Line Coupler module II Theory When a large amount of power is coupled for using as a divider the line length and interval are not enough for coupling the large amount of power to the desired level Therefore in case of the coupler for power dividing a branch line 15 inserted to introduce the power coupling of the great amount A coupler using the above method 15 called a Branch Line Coupler Fig 4 1 is a comparison of a Directional Coupler and a Branch Line Coupler Ini I The line length and interval ore not enough for coupling the large emount of power to the desired level tine 2 _ une 21011 branch line is inserted to introduce the power coupling of the great amount Fig 4 1 Directional Coupler and Branch Line Coupler When explaining the Coupling the lines are spatially separated so that it 1s explained by a concept of the Capacitance More specifically the coupling is a comprehensive meaning for referring to the electric magnetic power transmission between two lines and implies that the direct signal transmission using lines can be included Therefore in case of the power transmission between two separate lines to connect lines for transmitting the power or to transmit by spatial jumping does not make any difference in terms of the coupling If a direct connection is perfo
16. i L i i i i 1 i 1 1 i i i i i i i i i 1 i i I i oce ene quem 4 1 1 4 1 1 1 i i 1 i i 1 i i i i i i i i i i i i P I i i I LI i 1 i i i 1 i i i 1 i 1 1 i i i i i i i i i i i i i _ 6 L i 1 i i i i i 4 1 i i P i i i i i i i i i i 1 i i Sw oO a ii i i i i i i i I i i i i a i 1 1 1 I E i i 1 i i i i 1 i i i 1 1 i i i i i 4 i i i i i i i I P I 1 i i pem op m puo domom pm m je 4 d i 1 i 1 i L i L i i i i i i i ii ii i i i i i i i I LI a l i i i a 1 E i i i i i 1 i a i i i b d bi 1 0 a 1 1 1 l i i i i i i i i 1 i i I 1 i i i i i I i P i i i i
17. 1 i 1 1 i 1 1 i i i 1 1 1 i 4 i i i i i i i 1 ree m proe seem cmm pem poa ecu og Dolas epe eap eu i i i i i 1 1 1 1 I E i I i i j i i i E i 1 i 1 i 1 i 1 I i 1 i i i i i i i 1 1 1 i See p mmm em eo L i i 1 1 i E i i 1 i I I i i I 1 1 i 1 i i i i 1 l i 4 i i 1 i 1 1 1 E 1 1 1 1 L i i i m ma m Mn ccm mn oe m d 2 4 28 uuluuLudaalolzchl LE docuaelzleakzdazakl d lzlzlzg2LhldJd 2L LlzLk i L 1 1 i i i i i 1 i i 1 i L 1 1 i i i i i i i l L 1 1 i 1 i i i i i i 4 i 1 i i 1 i i i 1 1 i i i M 1 1 1 1 I i i i 1 i i i i i i i 1 i 1 4 1 4 i 4 V W T d 1 4 14 T17587700 a 7v 74 72 wv 37717148794 a8 10 10 84 92 V d V 1 i 1 1 1 1 i i i i i 1 i 1 i i i i i i 1 4 i 4 1
18. H plane pattern can be expressed as follows sin 2 cosi E cos d sind where a is the length of the slot Theoretically E plane and H plane patterns should be shown as Fig 112 6 Input Impedance of Microstrip Antenna Because the input impedances of the 2 slot array antenna and the 4 2 rectangular patch antenna is resistance components reactance component 0 they have good radiation characteristics The approximate for the input resistance is as follows 60 00 60 K n Where a 18 the length of the slot and NO 18 the wavelength in free space I209 uw a PLANE E FLARE Fig 14 12 Theoretical E and H plane Radiation Patterns for Two Slots Excited 74 with Same Amplitude and Phase b 2 where lt X Ideally because the input impedance of the patch is about 120 the impedances of the microstrip line and the input terminal of the coaxial cable should be 1209 However in order to connect with the 50 Q coaxial cable used in the antenna experimental set the 50 microstrip line is used To match the impedance between the 50 microstrip line and the 120 Q patch the 4 4 impedance converter as shown in Fig 14 13 is used The 4 impedance converter is useful for impedance matching at the narrow band The chracteristic impedance Zj of the 4 impedance converter for matching the impedances 4 and Z is as follows 4 p Z 2 9 Fi
19. P3 in Pg 4 E Ig 2 2 9 Therefore the right hand side of lt 2 becomes 2 so that i If 2 50 is used as a basis Z 250 and 7 35 4 Branch Line Coupler be easily formed with the simple equation by means of various transmission lines such as Stripline Microstrip Line or the like In case of Microstrip Line the characteristic impedance of 50 9 plays an standard role so that the line width becomes broader at an impedance lower than 50 and narrower at an impedance higher than the value Branch Line Coupler has a disadvantage of having a narrow available frequency band With a basic 2 Arm configuration shown in Fig 4 2 it properly operates in the band width of about 10 of the main frequency Adding one Shunt Arm in a manner that the overall shape is like a combination of two 90 Branch Line Couplers is required in order to broaden the band width Fig 4 3 shows a broadband 3dB Coupler By using this multiple shapes the operational band width can be expanded up to 2596 of the main frequency but the physical size becomes larger As a result a minimization by bending the line of each Arm to form a bent shape 15 necessary 321 240 Fig 4 3 Broadband Branch 90 Branch Line Coupler Measuring Instruments Item Module Name AT6030D Spectrum Analyzer tracking generator 1 030 20 Branch Line Coupler LX 1 1 2 2 5 5 500 Load NEN NEN
20. When the wire of the antenna is used by the resonance with RF it is called the RF excitation 70 Voltage Electric Wave fo Inttinsic Frequency The wire of a constant length is also resonant for the radio frequency having integer multiples of the intrinsic frequency fo Fig 14 5 RF Excitation of Wire The voltage and current distribution on the wire has the minimum current and the maximum voltage at both ends the maximum current and the minimum voltage at the 4 distant and this 1s reversed at every 4 period A point having the maximum voltage or current is called the anti node and a point having the minimum is called the node When the antenna wire is excited with the standing wave the power source may be connected to the current anti node or the voltage anti node as shown in Fig 14 6 The former is called the current supply while the latter 15 called the voltage supply 2 S C E Current Voltage Supply P D Fig 14 6 Current and Voltage Supplies and Their Vottage and Current Distribution for Open Straight Antenna Having Length of 2 or 34 2 In Fig 14 6 which indicates the direction of current at a certain moment as an arrow it should be iF noted that the current direction of two neighboring standing waves becomes opposite 180 and the voltage and current distribution can change according to the supplying point For example bo
21. 1 h J uf 1 0 t j t F Fig 8 3 Generating Process of Standing Wave from Incident and Reflected Waves As such a waveform which seems to stand still by mixing the incident and reflected waves while they simultaneously exist in the transmission line is called the standing wave misy 5 jit y ou X i a For 71 57 matching b For Z Z mismatching c For 71 0 short d For 715 open Fig 8 4 Effective Value Change of Standing Wave in Transmission Line 36 When the load impedance and the characteristic impedance of the transmission line are matched the voltage size of the standing wave occurring in the line is constant as shown in Fig 8 4 a However when the line and the load are mismatched as shown in b the incident and the reflected waves simultaneously exist in the transmission line and the standing wave occurs by mixing two waves The standing wave has a period of 2 and the difference between the maximum and the minimum points of the wave becomes larger as the reflection larger Not illustrated in the figure but the standing wave can also occur for the current The ratio of maximum to minimum of the standing wave 15 called VSWR Voltage Standing Wave Ratio p and defined as follows V 14 11 VSWR om y py min In general SWR Standing Wave Ratio means VSWR Voltage Standing Wave Ratio and is a real number value having no unit Or the size of the refl
22. 10 P4 P1 dB The following directivity represents the difference between the power desired for coupling and the power not desired for coupling Directivity Isolation coefficient dB Coupling coefficient dB 10log o P4 P1 d8 The directional coupler shows the same properties even if its input and output is changed That is if the signal is input to port 2 it directly is transmitted to port 1 A portion of it is coupled to port 4 and port 3 is isolated is used with each coefficient in order to obtain positive values for convenience Measuring Instruments Item Name Module Name AT6030D Spectrum Analyzer tracking generator 030 4 Directional Coupler 1 1 5 5 500 load IV Experimental Procedures 1 Connect all the lines to form a circuit as shown in Fig 3 5 ing Parker Rea C2 3 Fig 3 5 Directional Coupler Experiment 2 Adjust the center frequency of the AT6030D f 1500MHz SPAN 3000MHz use cable connecting the input and output port of AT6030D and then Calibration 3 Connect the AI RF3030 4 Directional Coupler module as figure above observing the Spectrum of AT6030D and measuring the inserted loss 17 4 Connect exchanging the port 2 and port 3 of the AT RF3030 4 Directional Coupler module that 18 the port 2 of the AT RF3030 A4 Directional Coupler module to the input of the AT6030D the port of the AT RF3030 4 Directional Coupler module with
23. 5 Shcottky Barrier Diode Fig 1 6 shows four types of the detector circuit used most frequently lt J atactor Qulp AF Le Dulp l c Voltage multiplier d Biased negative peak detector Fig 1 6 Basic Configuration of Power Detector a 15 a positive peak detector which can obtain a positive output If the amplitude modulation is not used the radio frequency signal input to the circuit the detector output is DC voltage proportional to the high frequency signal level and the output voltage is positive b is a negative peak detector where a reverse diode is arranged unlike a Therefore a negative detector output is obtained as the output c is a voltage multiplier which uses two diodes in the circuit The circuit can obtain the output twice larger than the b detector d 15 a biased negative peak detector where a portion having an IF VF characteristic of better linearity is selectively operated by flowing small DC bias to the diode This detector can increase the measuring 2 sensitivity when the high frequency signal level 1s low In case of the actual detector the input power should be transported to the key element of the detector diode without loss To increase the detector efficiency the impedance matching is very important An L C or stub is used at input terminal for matching or an inductor for DC return can be used as a part of the matching element If the impedan
24. 50 9 load and then measuring the Coupling Coefficient C of AT RF3030 4 Directional Coupler module 5 Connect exchanging the port 3 and port 4 of the AT RF3030 A Directional Coupler module that is the port 4 of the AT RF3030 4 Directional Coupler module to the input of the AT6030D the port 3 of the AT RF3030 4 Directional Coupler module with 50 load and then measuring the isolation Coefficient I of the AT RF3030 4 Directional Coupler module and directivity D C V Results Note If unused ports are not matched the reflected signal may flow back to other ports which leads to inaccuracy in the measurements lt Table 2 1 gt Characteristics of Directional Coupler Coupling Transmission Isolation Coefficient directivity Frequency Coefficient Coefficient Example Coupling Coefficient P3 dBm P dBm 10log10 P3 P dB VI Review 1 What is the average coupling coefficient dBm of the used coupler in the rage of 1 7 GHz I 9GHz In other words which decibel dB Coupler 15 it 2 What kind of problems are caused when the unused ports for the measurement are not matched 3 How much signals are detected from port 1 2 and 3 when the signal having a frequency of 1 5GHz and a power of 10 dBm is used for port 4 shown in Fig 3 4 Calculate referring to Table 2 1 4 Find and explain an example of the application circuit using a directional coupler 4 Theory and Experiment of Branch Line Coupler
25. Inside MMIC The following data sheet shows the specifications of the MMIC amplifier used the AT RF3030 21 module 64 BROADBAND DcipBGHz low power upio 13 5 dBm output AMPLIFIERS MAXUME GAM typical POWER een AMG Am mz Gb GHr I PEL i 2 8 4 8 108 Gk ima 054 121 121 a M3 61 73 32 4 Iz wb T 2 Wl uda 8i 1 Iz x 15 14 I 2 215 T HE RE M aui u TE oca 47 1 42 4 ba 13 18 mim 004 uos rii o Cur RE irons 1118 054 nz ws ui ud n x Re 12 1 53 v us HE THE i tui le i neis RE priu 14 i oe 22 1 HI re see suggested layout 1 075 for ERA modal features a low hama resstanca a Minature microwave ampliar a frequancy range DC to GHz urabla io 16 GHz a upto 18 4 dem typ 18 5 dem min output power absalute Maximum ratings Operating temperature 45 to 855 storage tampaeratuna 355 ta 15252 NETTES a zara at 1 dou 54 ES L
26. Point IP3 refers to a point where the fundamental output power and the IM3 component increase without saturation so that two power points become equal This point is used as an index for evaluating the linearity As shown in Fig 13 4 if the output power increases IM3 also increases Because increasing rate of the IM3 component 15 faster than that of the fundamental signal the increasing leads to the equal point of the fundamental and the IM3 components which is called IP3 IM3 increases faster than the fundamental signal When the input signal of x 0500 a is used in the non linear system the output y has an infinite geometrical series equation of y a bx Here the first order term b is the putout of the fundamental frequency signal Because IM3 is the signal coming from the third order term it increases with a slope of the size of the input signal to the third After all on the dB scale IM3 increases with a slope three times larger than that of the fundamental signal The above figure shows the increase of the output power and IM3 on the dB scale according to the increase of the input Dower Fower fundamental Freq Freq Freq Freq gt Output Increase of Input Signal 63 Output Pawer Power of Third term Power assumed not to be soturated Output 1 3 0123 d P PME qd IP 3 im Order Intercep Paint Signal Power actually saturat
27. a Even Mode Excitation b Odd Mode Excitation Fig 10 5 Even and Odd Mode Analysis of Wilkinson Power Divider 3 3 12 51 0 03 10 5 5 Sypty A TT 1 5 5 5 107 0 When signal is applied to port 2 it becomes 0 707 V times or half of the power at port 1 and the others 12 513 521 931 0 707 become 0 707 times in the same way and their phases are delayed by 90 Since each port is matched S11 S22 S33 0 while since port 2 and port 3 are isolated S73 S32 0 If the input is applied to port and the output port is matched power is not consumed at the resistor Therefore when the outputs are matched the divider has no loss While when port 2 and port 3 are mismatched only the reflection power is consumed at the resistor 49 vr 2 2 2 3dB I __ 75 Fig 10 6 1 X 8 Divider The Wilkinson power divider as described above is a 2 way divider By utilizing this 4 way or 8 way divider can be made Like the 8 way divider shown in Fig 10 6 the input signal is attenuated by 3 dB when it passes through one step For example if a 7 dBm signal is applied to the input eight 2 dBm signals can be obtained eventually III Measuring Instruments Item Module Name AT6030D Spectrum Analyzer tracking generator 030 8 Power Divider 500 Load SMA SMA IV Experimental Procedures 1 Connect the input and output of the AT6
28. can be divided into the electric and the structural resonances The electric resonance is formed from energy exchange of the opposite imaginary of L and C while the structural resonance occurs when the wavelength becomes a multiplied number of half wavelength or 1 4 wavelength proportional to the wavelength of the corresponding frequency One of devices using principle of the resonance is the filter In general meaning the resonance can be defined as a phenomenon having selective characteristics for the frequency the RF systems have individual frequency bands so the signal should be processed to select the corresponding components To all cases selecting the frequency the concept of resonance can be applied As such the resonance is a basic concept which is used in various RF circuit elements such as the filter the oscillator the frequency counter and the antenna Then the electric resonance commonly used in the electric circuit will be described in details The electric resonance means the so called LC resonance The inductor and the capacitor have characteristics of accumulating and discharging the electromagnetic energy and shows the opposite frequency characteristics The inductor has smaller impedance as the frequency lowered while the capacitor has smaller impedance as the frequency increases Connecting two elements of these characteristics causes the resonance at a certain frequency The resonance circuits which can be formed by 4 comb
29. can damage the circuit then display the relation curve of P2 f on the AT6030D so the gain of the MMIC Amplifier G Pj V Results Table 13 1 Measuring Gain of Each Port Gain Measuring 1 Gain Measuring 2 104 Att 204 Att dBm y GHz Output Output Output 5 dBm Gain dB Voltage V dBm Gain dB Considering the maximum measurement range of the detector the attenuator is connected to the input terminal of the amplifier VI Review 1 Find gain of the MMIC amplifier from the measured results 2 Does the gain change when the attenuator is changed from 20 dB to 10 dB in the above procedures If so what 1s the reason 3 Explain why the attenuator is used in the above P dB measuring experiment 4 Explain about P Db and of the amplifier 5 Find return loss gain and P dB for 2 5 GHz from the data sheet of MMIC used in the AT RF3030 21 module 6 Find out various active elements used in the amplifier 67 14 Theory and Experiment of Patch Antenna I Objective To comprehend the principle and characteristics of the antenna using the AT RF3030 22 Patch Antenna module II Theory 1 Antenna The antenna is a device built in the air for effectively radiating electric wave for the purpose of wireless communication or effectively maintaining the electromotive force by the electric wave That is the antenna
30. circuit 030 5 whose one end is terminated by a certain load and to learn how to match it by means of the 4 converter and the parallel stub AT RF3030 6 II Theory 1 Unmatching and Reflection 277 Fig 7 1 Reflection in Transmission Lines As shown in Fig 7 1 when the characteristic impedance Zo is different from the impedance of the load connected to the terminal part of the incident wave 15 reflected at the load and the standing wave is generated in the transmission lines The voltage reflection coefficient is pa Ve 2172 77 22 Where V is the amplitude of the reflected voltage and V is the amplitude of the incident voltage In this case the ratio of the incident power to the reflected power 1s P Where P is power of the reflected wave and P is power of the incident wave When the load at the terminal of the transmission line is same with the characteristic impedance the transmission line is called matched In this case the reflection does not occur and all the incident power is transmitted to the load That is if Z Z 0 and 0 Problems caused by the reflection are as follows Generating the standing wave in the transmission line Loss of the transmitting power Possible oscillation due to the circuit instability Damage of sensitive elements Causing arc discharge the high power circuit Undesirable interferen
31. for a signal source of microwave generates excellent oscillations in purpose but the oscillation in other circuit means the electric components undesirably caused at more than a specific level In particular the oscillation should be removed from circuits having gains such as an amplifier a frequency or a frequency doubler The oscillation is based on a concept of feedback When a loop using an output signal as an input is formed the output signal is fed back to the input and becomes bigger with having gains As shown in Fig 1 1 if the amplified signal 15 fed back the signal grows bigger and bigger Feechoack 7 Fig 1 1 Feedback Loop The oscillation is initiated by a transient phenomenon or noise at the first step and gradually approaches the stable phase An active element is required to obtain gains during the oscillation and a negative resistance is also required IMPACT Gunn diode or the like is used for a single port and FET or transistor in addition to a passive element is used for the port so that the input port has a negative resistance Colpitts or Hartley oscillator having s lumped element is used in the low microwave frequency range In this case a resonator is used for the input or output in order to increase the stability That is the oscillator can stably operate by an insertion of a resonator and the selective feedback of a certain frequency as shown in Fig 1 2 As shown above it i
32. frequency 15 easily changed by changing either of them without changing both More general and common method is to change the capacitance of the resonance part When the capacitance of the varactor diode changes due to the voltage change applied to the varactor diode the resonance frequency of the resonance part changes which eventually leads to the change of the oscillation frequency The VCO Voltage Controlled Oscillator is made based on this principle The VCO can be changed by the voltage but it has problems that it is weak for external impacts such as the temperature change or voltage instability That is the desirable oscillation frequency is not fixed but fluctuated so the system can not operate in normal condition because the source signal is fluctuated Therefore various techniques are required to increase the frequency stability of the VCO A series of the procedures is called the locking in short The PLL Phase Locked Loop is a circuit combination method used in RF for fixing the frequency source against the external impacts The VCO is usually regarded as a part of the PLL but strictly speaking in terms of RE the PLL is a powerful tool and methodology for smoothly fixing and changing the frequency of the 5 VCO Fig 1 4 shows a specification of the SZ COM 16009001 2350 VCO used as the VCO E k Contact Assignments RF Out All other contacts are Ground SSB Phase Noise dBc Hz Su
33. i i 1 r 1 i i 1 mw 1 411 3 5 53 1 14 i i i L 1 41 4 4 14 1 B i i i i i io i 1 i i i i RE l i i 1 i i i i i i 1 i LI i I 1 i 1 i i I a i i i 1 1 i i i i i i i i 1 DU l n i i i 1 i i i i ii ii i i i i i i i i i i i i baia eee cali aia Gee aa ies I i 1 1 i i i i i i i L 1 i i i i i I 1 i i i i t I i i i i 1 i i i i i i i i i i i i i i i i i i i I i i SPS a7 Prt er Pe de omo m mom mmgEo R amp LI B u L 4 pocme mocmme g 4 j eee ee lH b om mon 1 i i i i 4 l i i i i i i i i i i i i i i i F i i i i i 1 LI i i i 4 i 1 i i i I i 1 i i 1 1 i 4 1 1 1 2 2 4 4 1 4 1 i 1 L i i i i i I i i i i i i i i i 1 i i 1 1 4 1 1 i i i i l i i i i i i i i i i i 1 1 1 i i 1 1 1 1
34. isolation 122008 of the power splitter V Results Table 10 1 Division by Wilkinson Powe Divider Frequenc Input Power Py Power P Power P power Output Power Output Power Transmission Loss dB 2 GH P dBm P gt dB ee 22122222 Pi dBm P5 dBm or Loss dB P dBm ae pw ft fof tf o bo fos VI Review 1 What is the average power divided by the Wilkinson power divider in the rage of 1 7GHz 1 9GHz In other words which decibel dB divider is it 2 What kind of problems are caused when the unused port for the measurement 15 not matched 3 How much signals are expected to be detected from port 1 and 3 when the signal having a frequency of 1 8 GHz and a power of 10 dBm is input to port 2 referring to the results 4 Calculate P P P P3 P2 P3 and values from the results in Table 10 1 5 Find other type elements which combine or divides power or make coupling part of the power 6 Build an experimental set using modules of the experimental instruments in order to obtain 511 or the return loss for port 1 of the Wilkinson power divider 21 11 Theory and Experiment of Ring Resonator I Objective To comprehend the characteristics and principle of the resonance using the AT RF3030 16 Ring Resonator module and obtain the resonance frequency II Theory The resonance refers to concentration of energy to a certain frequency The resonance
35. mod i 1 i P i i i 1 i i i i i i i i i i 4 i i i i i 1 i i i i i i 1 i ii i i l i i 1 i E i i i i i i 1 i i i i 1 I i i i i i i i i i i i i 1 i 1 i i I i i 1 i CR re im in qnid i il i a 1 i i i i i 1 i i i i i i i i i i i 1 1 i i i 1 E i 1 1 4 1 1 i i i i i i 1 i i i i i i i i E i i i i i 1 mom mcm cm ccc ccm cms ae e mo co Gp moGQ GO Re c o ec mode mom m Ee i b d o 4 om od mm m jum 1 i i i i ii i i i i i i i i I i i I P i 1 i I 1 1 1 i i i i i 1 i i i i i i i 1 i i i i i i i I i i i i 1 i i C c 83 Outnput V Fig 6 Characteristic Graph III of Detector C 3 Symbol of Microstrip ransmission Line Branch Line Coupler gt Hybrid Ring Coupler gt 548 Tee i lt Wilkinson Divider gt lt Attenuator gt lt Variable Attenuator gt lt Amplifier gt lt Oscillator gt lt Antenna gt 5 4 Ar Switch lt Circulator gt lt Isolator gt xer gt Po px lec ws Phase Shifter gt lt
36. of right and left ports and not to the other port In other words the signal 15 transmitted from port 1 to port 2 18 transmitted from port 2 to port 3 and then transmitted again from port 3 to port 1 Reverse transmission of the signal is isolated due to the damping effect Note that only the reflected signal of port 2 is transmitted to port 3 when the signal is transmitted from Port 1 to Port 2 and no signals are transmitted to port 3 when there are no reflected signals at port 2 As three Cases shown in Fig 2 2 since the circulator transmits signals with having a direction by rotating in one direction it originates from a circle Rotating direction in a symbol represents the direction of the power transmission at each port 11 Part 3 200 eztehing Fig 2 3 Isolator Using Circulator If a matching circuit 01509 is connected to port 3 as shown in Fig 2 3 all the signals from port 2 are absorbed to port 3 Therefore since even the reflected signal of port 2 is not transmitted to port 1 this circuit can be used as an isolator When the circulator is applied to the wireless communication system it can be used as a duplexer by using one common antenna for transmitting and receiving As shown in Fig 2 4 amplified transmitting signals are transmitted through the antenna in a clockwise direction and the received signals by the antenna are transmitted to the receiver Transmitter Armenia Antenna E e d
37. sampled or the power is used to be divided Fig 3 4 represents a simplified structure and principle of a directional coupler An interval s between two neighboring lines 15 such an important design variable which determines the coupling amount of the directional coupler that the coupling amount can be determined by adjusting the s interval The coupler has generally four ports where some ports transmit signal but the others don t Fig 3 4 Transmission Principle of Directional Coupler When the power is input to port 1 it proceeds to port 2 along the microstrip transmission line A portion of it proceeds with coupled to port 3 and ideally the power is not coupled to port 4 so that no signals are detected With this property the coupler can have a direction Coupling coefficient transmission coefficient isolation coefficient or directivity is used for representing the electric property of the directional coupler Generally 10dB coupler means a coupler having a coupling coefficient of 10 dB Coupling coefficient 16 can be defined as follows Coupling Coefficient 10log 10 P3 P1 dB The coupling coefficient represents the electric coupling level from port to port 3 and the transmission coefficient represents the transmitted level to port 2 The isolation coefficient represents the output to port 4 which is hardly detected for actual signal Transmission Coefficient 10log 10 dB Isolation Coefficient 10log
38. specific frequency and is formed by arranging and combining the serial and parallel resonances 57 5 Pass Filter The APF passes signals of all the frequency components and only delays their phases This filter is commonly used for the phase delay circuit H f f 0 Fig 12 3 shows basic filter circuit using LC Low Pass High Pass Band Pass Band Stop 9907 000 4 E 7 12 41 Basic Filter Circuit Using LC Figs 12 2 4 show filter circuits using the microstrip transmission lines Stepped Impedance Steb line Eliptic Fig 12 5 Low Pass Filter Using Microstrip Transmission Line Direst Coupled End Coupled Edge Coupled Tapped Edge Coupled 11 t Hairpin Coupled Line Interdigital Direct Coupled Eliptic Fig 12 6 Band Pass Filter Using Microstrip Transmission Line 111 Stub Stub Edge Coupled Coupled Open Fig 12 7 Band Pass Stop Filter Using Microstrip Transmission Line 6 Measuring Insertion Loss and Skirt The most important characteristics of the filter are the insertion loss and the skirt The insertion loss means the power loss occurring during passing of the signal through the filter and in the pass band S is less than O dB and has a value of near O dB The skirt characteristic having a skirt shape of women indicates how clear it 1s to separate the pass band and the stop band The insertion loss is better as it is smaller while the skirt curve has a better characteristic w
39. terminal of the detector CC cL 2 1 iau Uf Fig 1 8 Matching Using Broad band Resistors In case of the detector not only the circuit for converting the fore mentioned frequency to the DC voltage but also the circuit for handling the detector output signal 1s also important If the input signal level has a low value like minus a few tens dBm the detector output also has a value lower than a few mV Therefore the signal amplification at the output terminal is necessary In this case when various fine properties such as offset voltage of the output terminal OP Amp are not calibrated the detector efficiency 18 degraded due to the addition of undesirable voltage Measuring Instruments Banana SMB SMA SMA X The frequency of VCO be changed by controlling the Vtune voltage Cautionl Take not to apply higher voltage than rated voltage to the power supply of the AT RF3030 1 VCO module and the terminal Higher voltage than the rated voltage can damage the circuit Caution2 Apply the power to the circuit after completely connecting all the modules as always IV Experimental Procedures 1 Connect all the lines to form a circuit as shown in Fig 1 9 1 SER Fig 1 9 Output measurement of VCO 2 In order to supply the operational voltage Vec and the tuning voltage Vu to the AT RF3030 1 VCO module set the Vec and Viune voltages of AT RF3030 1 VCO to 12 and OV respectivel
40. the current so it has the maximum at both terminals and the minimum in the middle Voltage Current The stancing wave on the sine wave is caused Fig 14 4 Voltage and Current Distribution on A 2 Wire Having Open Terminals Because the standing wave occurs on the wire sizes of the voltage and current on the wire are determined by its positions The on board antenna is a method for flowing the RF current on the wire and it causes the standing wave on the wire Fig 14 4 illustrates a case that one standing wave occurs when the wire length 15 2 What happens when the frequency of the power source in Fig 14 2 is changed to value twice three times of the resonance frequency fo The A 2 wire for fy becomes for 2fy while it becomes 2 for Therefore in any case it becomes an integer multiple of 2 and a plurality of standing waves occur on the wire so that the wire is resonant In such a case the voltage and current distribution on the wire will be as shown in Fig 14 5 The resonance frequency for the LCR serial circuit is only one It is not only one actually when performing an experiment The resonance can occur at a certain multiple frequency but the resonance occurs at several frequencies which are integer multiples of the lowest resonance frequency fo for the wire Here fo is called the basic frequency or intrinsic frequency of the wire and 2fo 3fo and so are called the harmonics resonance frequencies
41. two rows in parallel Output of one Amp 2 1 Dmider 104 Combiner Fig 13 1 Amplifying Output Power As such to increase the gain and the power simultaneously the amplifier should be connected in a structure as shown in Fig 13 2 fairey Power y al 4 Y mh 1 FM em Ir rect hain See Canr zz hon Fig 13 2 Multiple Power Amplifier Increasing Gain and Maximum Output Power 2 4 1 dB Gain Compression Point All the amplifiers cannot radiate infinite power but has a certain limiting point An index to indicate this limiting point that is the maximum power point is Assuming the output power of the amplifier is not saturated the output power where the difference between the unsaturated power and the actually saturated curve becomes 1 dB is 4 In addition the gain in this case is called For example if OdBm is input to Amp having the gain of 20 dB the output is 20dBm but it does not guarantee the output of 30dBm when 10dBm is input gain slowly decreases as the input power increases so that the saturation state where the output power is not increased any more when an input power above the certain level is used That is dB gain compression point is used for indicating the maximum power point available before reaching the saturated power E
42. 030D Spectrum Analyzer with cable and calibrate it obtain the referring voltage 2 Connect all the lines to form a circuit as show in Fig 10 7 Connect the output of the AT6030D to the port 1 of the AT RF3030 8 Power Divider module connect the input of the AT6030D to the port 2 of the AT RF3030 8 Power Divider module connect 50 9 load to the port 3 of the AT RF3030 8 Power Divider module obtain the inserted voltage P2 Because this is two sub power splitter the ideal value of the distribution loss is so the inserted loss L P 5 3 Fig 10 7 Power Divider experiment 3 Connect exchanging the port 2 and the port 3 of the AT RF3030 8 Power Divider module measure 50 the inserted voltage P5 inserted loss L P3 3 4 Connect the output of the AT6030D to the port 2 of the AT RF3030 8 Power Divider module connect the input of the AT6030D to the port 3 of the AT RF3030 8 Power Divider module connect 50 9 load to the port 1 of the AT RF3030 8 Power Divider module obtain the inserted voltage isolation coefficient IZP P 5 Connect the output of the AT6030D to the port 3 of AT RF3030 S Power Divider module connect the input of the AT6030D to the port 2 of the AT RF3030 8 Power Divider module connect 50 9 load to the port 1 of the AT RF3030 8 Power Divider module obtain the inserted voltage isolation coefficient I P Ps the effective bandwidth V is the work bandwidth of the power divider when the
43. 1 Adjust the center frequency of the AT6030D to 1500 SPAN 3000MHz Connect the input and output of the AT6030D Spectrum Analyzer with cable and calibrate it Then measure the reference level 2 Connect the T type attenuator of the 030 7 T 1 Attenuator module Connect all the lines to form a circuit as shown in Fig 6 3 Measure the accessing level sothe attenuated value A P Record the input signal dBm output signal dBm in the attenuated value table 6 12 TOLL ULE c 4 ELT fh Fig 6 3 T type attenuator Experiment 3 Connect the type attenuator of the AT RF3030 7 T Attenuator module Connect all the lines to form a circuit as shown in Fig 6 4 Measure the accessing level P so the attenuated value A P Record the input signal dBm output signal dBm in the attenuated value in table 3 12 26 T mE Ld ir Fig 6 4 II type attenuator Experiment V Results Table 6 1 Characteristics of T type and type attenuators VI Review 1 What is the average attenuated value of the used attenuator in the rage of 1 7GHz I 9GHz In other words which decibel dB attenuator is it 2 Explain the definition and principle of the attenuator 3 Design a 10dB T type Attenuator 21 7 Theory and Experiment of Matched Unmatched I Objective To measure the reflected power in an unmatched
44. 11 Theory and Experiment of Ring Resonator 2 2 2 22 00000000200000000600000000005055 8 00 000000000000000 32 12 Theory and Experiment of Low Pass and Band Pass 56 13 Theory and Experiment of MIMIC Ampliiter s ss cascsnsccanesseasuensnessuaasngesoanconscucosbenduensunasnencbeataencasesneassaasns 61 14 Theory and Experiment of Patch Antenna 68 7 5 5118 78 1 UMS 2400 A16 Output Electric Power eese nennen nnne 78 PAS 111848 TT 80 3 DVIHDOL OF s 94 EXPERIMENT 1 Theory and Experiment of VCO and Detector I Objective To measure frequency and output power changes according to the variation in the tuning voltage of an AT RF3030 1 VCO module with an AT RF3030 24 Coaxial Detector and to comprehend the basic principle of the VCO II Theory 1 VCO Voltage Controlled Oscillator The VCO is an abbreviation for the Voltage Controlled Oscillator The VCO 16 an oscillator which control output frequency f f2 within a certain range by changing the tuning voltage Viune in addition to the bias voltage VCC applied to the VCO Here the oscillation means that energy is concentrated in a specific frequency region due to the electric or structural resonance An oscillator used
45. 6030D and then press the MARKER and PEAKSEARCH to obtain the frequency power on the maximum point this data is the receiving power from antenna L The difference between the two data 1s the frequency response characteristics of the antenna Fig 14 15 Antenna Transmission Reception experiment 3 According to radar formula Lr Le Which Lr receiving power level dBm Lictransmitting power level dBm G zthe power of the transmitting antenna G the power of the receiving antenna Nz20Log 4 mR A R the distance between the transmitting antenna and the receiving antenna wavel ength Then calculate the Gr G for the two antennas are the same G G 4 To the direction angle need access two same antennas at input and output port One antenna is static and other antenna around moving so that the angle between the two antennas is changed Due to Radiation of the antenna is different in different directions the gain are also different under the changes in the relative angle between each position 76 V Results Table 14 1 Measuring Antenna Received Voltage Antenna Distance m 05 06 07 08 109 1 11 Reception Detected Voltage V VI Review 1 Explain how the detected voltage changes according to change of the modulator frequency when the square wave of the function generator 15 Lo region 2 Explain the difference between gains of the antenna and the active
46. DC voltage is used for 6 the low power measurement of few mW a few hundreds mW according to the diode capacity The Shcottky barrier diode is commonly used for the detector Hereafter it will be abbreviated as the SBD Shcottky Barrier Diode for convenience One big difference exists between the SBD and the common diode The general diode is formed by the junction of p type and n type semiconductors p n conjunction but the SBD 15 formed by the junction of metal tungsten platinum or chrome and a semiconductor n type It shows a similar characteristic for the rectification with the p n junction but there is a big difference inside The p n junction diode has both majority and minority carriers for transporting charges but the SBD has only majority carriers As a result high speed operation 1s possible and it is widely used in radio frequency region One of the important characteristics of the SBD 15 that reverse and forward voltages are low The reverse voltage is lower than that of the p n junction diode by one order of magnitude and the forward voltage is about half of that of the p n junction diode Fig 1 5 shows the SBD equivalent circuit at radio frequency region It comprises a serial resistor R a non linear junction resistor Rj and a non linear junction capacitance Cj and the and C values should be small when SBD 16 used for a detector and a mixer es gt 0 Symbol b Equivalent Circuit Fig 1
47. IV Experimental Procedures 20 1 First adjust the frequency of AT6030D in f 1500MHz SPAN 3000MHz Connect the input and output of the AT6030D Spectrum Analyzer with cable and calibrate it Then measure the refer voltage P measure observing the frequency with AT6030D measuring the inserted L lt 3dB or not when f 1800 2200MHz EA 11 E mE Fig 4 4 Branch Line Coupler Experiment 2 Connect all the lines to form a circuit as shown in Fig 4 4 Use cable connecting the port 1 of the AT RF3030 20 Branch Line Coupler and the output of the AT6030D port 2 to the input of the AT6030D port 3 and port 4 with 50 9 Load Now it can obtain relation curve between the output voltage of port 2 and frequency so the inserted loss L P gt P 3 Connect exchanging port 2 and port 4 of the AT RF3030 20 Branch Line Coupler measure the relation curve between the output voltage of port 4 and frequency so the inserted loss L2P4 P the asymmetry of this two ways is P5 P4 4 Connect exchanging port 4 and port 3 of the AT RF3030 20 Branch Line Coupler measure the relation curve between the output voltage of port and frequency so the isolation 5 In common the signal input from the port 3 output from the port 2 and port 4 without signal from port 1 Because the port 2 and port 4 are near very much so the Branch Line Coupler has another name of 3dB bridge
48. Low Pass Filter pP d A A High Pass Filter Band Pass Filter 84
49. Standing Wave Ratio I Objective To comprehend the reflected wave and the standing wave by measuring the reflection coefficient and wavelength and the standing wave formed in the transmission line when a terminal of the microstrip line 15 short open or matched Theory When the transmission line is infinitely placed as shown in Fig 8 1 a only the traveling wave exists in the line when a microwave signal 15 applied Or all the incident waves are transmitted to the load and only the traveling eave exists in the line when the characteristic impedance Z normally a line of 509 is used for the microwave and the load impedance Z of the transmission line are same 41 Zo as shown in figure b Such a state is called a matching state e AN Incident wove Incident wove V V gt Transmitter wave Reflect wave Reflect wove j li F9 3 SS m 20 1 22 Fig 8 1 Electric Wave Matched Transmission Line However if the load impedance and the characteristic impedance of the line are not same 2 gt 7 as shown in Fig 8 2 a part is reflected and the other part is transmitted to the load It is same when a transmission line of the characteristic impedance 241 1s connected to an infinite transmission line of different impedance 72 as shown in figure b which is called a mismatched state In a mismatched circuit the ratio of incident wave to
50. V Review 1 Plot the insertion loss frequency characteristic as a graph from the measured values of two filters 2 Find the stop frequency of the filter from the measured values of two filters 3 Explain about the waveguide filter 4 Design the band pass filter using L and C Ripple 0 548 Center Frequency 1GHz Band Width 10 3 Impedance 50 60 13 Theory and Experiment of MMIC Amplifier I Objective To comprehend the principle of the MMIC amplifier using AT RF3030 21 MMIC Amplifier module the amplification gain and the characteristic of P dB II Theory The amplification means increasing the amplitude of a signal while keeping the signal itself The characteristics of the amplifier in the transmitter receiver vary according to its purpose of the use Because the transmitter has to radiate the signal from its antenna at the maximum power so that the electromagnetic wave can reach the target it needs to be amplified to higher power as much as it can while because the receiver has the received signal of very small size and noise in addition to the original signal it needs to be amplified with minimizing the noise The power amplifier is mainly used for the transmitter while the low noise amplifier is used for the receiver Details on the amplifier will be described hereafter 1 Gain and Maximum Output Power The gain and the maximum output power are often thought as equal concepts but the gain represents
51. V Review 1 What is the average coupling dB of the used coupler in the rage of 1 7GHz I 9GHz In other words which decibel dB Coupler is it In addition what is the available frequency range of the coupler at the instance 2 What kind of problems are caused when the unused ports for the measurement are not matched 3 How much signals are detected from port 1 and 3 when the signal having a frequency of 1 5GHz and a power of 10 dBm is input to port 2 shown in Fig 4 4 4 Explain how the output signals of port 2 3 and 4 would change if the input signal is connected to port 1 5 Explain the definition and principle of the Branch Line Coupler 6 Find and explain the example of an application circuit using the Branch Line Coupler 21 5 Theory and Experiment of Hybrid Ring Coupler I Objective To comprehend the operational principle and purpose of Hybrid Ring Coupler using AT RF3030 9 Hybrid Ring Coupler module II Theory The hybrid ring coupler is a coupler also known as the rat race coupler Basically it is used for the half power divider as the 90 Branch Line Coupler but the difference from it is having a phase difference of 180 for the signal power The 90 Hybrid Coupler described above is used for a divider or combiner having a phase difference of 90 while the Hybrid Ring coupler is used when having a phase difference of 180 Fig 5 1 shows the external appearance of the Hybrid Ring Coupler circ
52. VSWR is more than 10 displaying on the AT6030D further more the maximum position of the slider module just is the minimum position of the slider module in shorting Note Use an average value because errors can occur during the measurements Theoretically VSWR is oo but due to the characteristics of the 1nstrument 1t 1s hard to measure the minimum voltage and the minimum point Therefore obtaining a huge standing wave ratio is satisfactory V Review 1 Is the measured standing wave ratio large enough as expected when the load is short and open 38 Otherwise what is the reason 2 Calculate the effective dielectric constant of the microstrip line Here the characteristic impedance of the line 7 50 the relative dielectric constant of the dielectric substance amp 2 4 thickness h 0 063inch and 126 69inch 3 When finding the maximum minimum point by moving silder module for the standing wave ratio side to side what is the reason for a case that the voltage at the measured maximum minimum point is different as the probe moves to the signal source 4 Calculate inversely the size of I from the standing wave ratio obtained In addition the load impedance can be obtained from the reflection coefficient When the characteristic impedance of the line Zo is 50 Q what 15 Z 39 9 Theory Experiment of PIN Diode Switch I Objective To comprehend the PIN diode switch which turns on off the signal or con
53. atching circuit shown in b of Fig 7 5 by using the transmission line will be explained When the load impedance of the circuit for matching with Zois 1 connect the transmission line as shown in a of Fig 7 6 and adjust the length amp in such a way that the admittance Y becomes 1 71 1 50 41 Independently as shown in Fig b adjust the length gt in such way that the admittance Y of the transmission line having a short or open terminal becomes Y5 1 Z5 jB 30 2 ay al oa LP X Sy ci Fig 7 6 Matching Using Stub Connect Fig a and b in parallel as shown in Fig c As such the transmission line connected in parallel as a distributed constant element is called a stub In this case the overall admittance Y is Yit Y 5 398 3 480 dE Therefore the overall impedance Zr becomes r E 50 Zi the matching is possible Matching with this method 15 called the parallel stub matching But it has a disadvantage of having very narrow bandwidth 4 Matching Using 4 transmission line Fig 7 7 Impedance of 4 Transmission Line As shown in Fig 7 7 if the load impedance Zi is connected by a transmission line having a length of 4 the overall impedance 18 2 L By using this property the resistive load be matched 7 means the impedance of the 4 transmission line F
54. cable and calibrate it 2 Open the TPR3002 3C DC Power and adjust the output to zero 3 Connect all the lines to form a circuit as show in Fig 9 6 Connect the output of the AT6030D to the port 1 of the AT RF3030 IO PIN Diode Switch module connect the port 2 of the AT RF3030 10 PIN Diode Switch module to the output of the AT6030D connect the 50 Q Load to the port 3 of the AT RF3030 10 PIN Diode Switch module Fig 9 6 Measuring Characteristic of PIN Diode Switch 4 Open the controlling voltage of the port 4 V 5 V that 15 V5 25V input from port 2 Note The voltage can t over 5V it will damage the AT RF3030 10 PIN Diode Switch 5 Connect the input of the AT6030D to the port 3 of the AT RF3030 10 PIN Diode Switch module 45 connect the 50 Load to the port 2 of the AT RF3030 10 PIN Diode Switch module Open the controlling voltage of the port 5 of the AT RF3030 10 PIN Diode Switch module madding V 5V input from port 3 When the voltage of the port 5 1s invariability connect the input of the AT6030D to the port 2 of the AT RF3030 10 PIN Diode Switch module connect the 50 Load to the port 3 of the AT RF3030 10 PIN Diode Switch module and then measure the isolation coefficient V Review 1 What 15 the reason for increasing narrowing the bandwidth the impedance of the 4 line for the DC bias in AT RF3030 10 PIN Diode Switch 2 2 Referring to the experimental results about the transmission and th
55. ce matching is not done properly the sensitivity of the detector 1s decreased so that accurate measurements are hardly expected 3 Impedance matching of detector The detector is a circuit for converting AC power to the proportional DC voltage In addition it requires transporting of the input power to the diode the key element of the circuit without loss The input impedance matching is of great importance in increasing the detector efficiency If the target for detecting 15 determined so that the frequency band is narrow and the efficiency and sensitivity are required the matching circuit is formed by using reactance elements distributed line such as L C stub or the like As shown in the figure the inductor used for DC return may be used a part of the matching circuit In addition when the circuit connected to the input is not open DC circuit a capacitor for isolating the DC may be necessary haaetaneg Elemert Detector Perctunre Element Fig 1 7 Matching Using Narrow band Reactance Elements If a broad band detector is required for the broadband the circuit is formed by inserting resistors in parallel In this case the impedance matching should be done by adjusting the resistance in a manner that the impedance 18 as close to 50 as possible With this circuit the input signal power 185 partially consumed so that the sensitivity of the detector is decreased for the broadband Therefore an amplifier is often used at the input
56. ce with other signal As described above when the reflection occurs system performance is degraded and many problems are caused Therefore it is very important to protect the element and minimize the reflection by matching the load in the input output lines transmitting the microwave energy in the system 2 Impedance Matching When the light proceeds in the air and encounters a medium part is penetrated and the other 18 reflected In the same manner when the electromagnetic wave proceeds along the line having the characteristic impedance Zo and encounters the transmission line having different impedance or the circuit part is 28 transmitted and the other 1s reflected As such certain condition should be satisfied order to transmit the maximum power to the load without generating the reflective wave A case where the condition is satisfied is called the impedance matching When the characteristic impedances are same there occurs no reflections regardless of structures of the line or circuit That 15 when the coaxial line and the microstrip line each having a characteristic impedance of 509 are connected there is no reflection 1 Impedance change according to the length of the transmission line Characteristic Impedance of line ZINE 12 Arg PL Fig 7 2 Load Impedance Change according to the length of Transmission Line As shown in Fig 7 2 when observing a certain load with connected by the tran
57. creased by 1 1000 However since a decrease of 1 1000 can be assumed to be negligible it will not significantly affect on the signal If the decreased power is too small to detect the accurate signal state by means of 30 dB other coupler that can detect greater power such as 20 dB 1 100 or 13 dB 1 20 coupler can be used In this case the decrease can be bigger than that of 30 dB so detecting proper power according to the condition is preferable Fig 3 2 illustrates 30 dB coupler 15 Insut Oder Input f 0004dBm Imi 0 999 8 outpul 2048 000118 Fig 3 2 30dB Coupler Another application of the coupling is a power divider A power divider means a coupler not used for identifying the signal property or the power level by sampling a small amount of power but for coupling the desired amount of power when the large amount of power is needed In addition when the power is coupled by means of the power divider the loss of power in actual signal lines will be greater As such it is used not for sampling power but for dividing power Fig 3 3 illustrates a power divider i ui 3 CHITI 0 Sm Fig 3 3 Power Divider Both the power sampling and the power dividing have a same principle but they can be divided to the power sampler and the power divider according to their application The power level used for coupling is different according to a fact that a small portion of the signal is
58. d region so that it can be radiated at the maximum In another direction the distance between two slots are different so they cannot be added with the same phase Accordingly the radiation pattern will have the main lobe of the maximum size in the y axis direction Maximum Main Lobe in Y axis Direction by Same Phase Radiation Attenuation in Another in Same Distance Direction by Phase Difference Different Distance F Fig 14 10 Analysis of Radiation Pattern in E plane Far Field Region for Rectangular Patch Fig 14 10 illustrates one slot in a three dimensional way In this figure each axis and 0 are used as variables for the basic equation a and b in the following equations and 0 are related values with the width a and the length b of the patch shown in Fig 14 10 The height h of Fig 14 10 16 related with the thickness of the dielectric substrate in Fig 14 7 and Fig 14 8 The radiation pattern on the E plane for two slots excited to equal amplitude and same phase can be 73 expressed as the following equation sin cos 7 ph MUS cos 00 cos where h is the height of the slot same as the thickness of the patch antenna substrate b is the distance between two slots same as the length of the patch antenna B 22 4 Radiating Slot Fig 14 11 Shape for Calculating Radiation Pattern on E and H plane for Radiation Slot
59. e isolation of the switch reasonable 3 Explain the principle of the switch composed of the microstrip line 46 10 Theory and Experiment of Wilkinson Power Divider I Objective To comprehend the operational principle of the Wilkinson power divider and the difference between the coupler and the divider though the power division of the Wilkinson power divider II Theory 1 Power Divider The coupler refers to the passive element which makes coupling part of signals in the RF signal path while the power divider means the passive element for dividing power That is the divider is a common name of the element used for dividing large amount of power and the coupler is more general name which includes not only the coupler s concept and the dividing power but also a concept of detecting power Among the coupler one that makes coupling large amount of power and divides the power can be called the power divider and the divider may be thought as one of the application concepts of the coupler The power divider divides power to equally 1 2 or EN or can divide power unequally The power divider can be easily formed by changing the input and output Fig 10 1 shows some examples of the coupler according to their P Power 2 Power 0 Divider pe Po Splitter H 1 wc ba b 2 Power Po Divider Pan 55 2 Fo 6 4 Fig 10 1 Functional Classification of Couple
60. ection coefficient can be known from the VSWR value VSWR In fact SWR is a same phenomenon as the reflection coefficient known as the degree of reflection of the load Matched load has a reflection coefficient of and VSWR of 1 The standing wave is mainly expressed as a non dimensional number and has a value from to Often VSWR is expressed in dB as follows VSWR dB 2000 VSWH The reflection coefficient 1 when the load is short as shown in c while 1 when the load 15 open as shown 10 d In both cases the perfect reflection occurs and the VSWR value becomes For the short the voltage in the load becomes minimum at a position of 0 while it becomes maximum for the open The standing wave occurring in the line is repeated in the microstrip line with a period of half of the guided wavelength 2 Therefore the guided wavelength can be obtained by measuring the interval between the minimum or maximum values which can be used for obtaining the wavelength of That is the frequency of the incident microwave can be calculated If the frequency is known the effective dielectric constant of the microstrip line can be obtained from the guided wavelength That is x 3x10 F 7 m Example 8 1 When the interval between the maximum or minimum values of the measured voltage 1s 54 mm calculate the followings D What is the
61. ed eee m m et ee Input Power Input IPS Fig 13 4 Characteristic Curve 5 MMIC Monolithic Microwave Integrated Circuit HBT Heterostructure Bipolar Transistor or MESFET Metal Semiconductor Field Effect Transistor is mainly used as an active element in the microwave amplifier This 1s used for forming the matched circuit at the input output terminal and the capacitor and the inductor are used for forming the MIC Microwave Integrated Circuit type in the microstrip line Recently it has developed to the MMIC Monolithic Microwave integrated Circuit where the active and passive elements are manufactured on a semiconductor die as a batch process MMIC 1 a key technology which can not only achieve minimization and light weight of the RF system but also increase the production yield by significantly decreasing used parts As shown in Fig 13 5 MMIC 15 simultaneously manufactured using the connection of unit element in addition to the passive and active elements on a semiconductor substrate as a batch process Therefore it has smaller size than the existing RF circuit substrate high reliability and uniform characteristics while it has disadvantages of difficult design almost impossible tuning and very long manufacturing time spiral Inductor Capacitor Transistor Compound Semiconductor Substrate Fig 13 5 Schematic Diagram of
62. element 3 Explain characteristics and types of the microwave antenna 4 Convert the detected voltage in lt Tablel4 1 gt then calculate the actually received signal with considering gain of the reception amplifier 5 Explain the principle of the PIN modulator 77 APPENDIX 1 VCO UMS 2400 A16 Output Electric Power Table 1 Output Frequency and Output Electric Power of VCO 24 C when 24 C when o 10 96 137 10 86 1 449 11 63 1571 4 0 1 623 10 89 1 664 o __ 1021 1375 L aw H0 OA 90 11 99 2 043 1 37 2 316 11 08 2 328 10 80 2 384 14 0 10 48 2 397 14 5 10 07 2 410 15 0 2441 2 458 2 468 2 12 2231 11 74 2 302 78 830 2221694 BM Ast 12241222 Varactor bias yoltagel Fig 1 Tuning Voltage versus Output Electric Power and output Frequency graph of VCO AR oaa eA Varartor bias voltage V 2 Tuning Voltage Versus Output Frequency error of VCO 79 tOFod 5 2C 04 8 oW Wo verartar bias Fig 3 Tuning Voltage Viune Versus Output Electric Power Error of VCO 2 Characteristic of Detector lt Table 2 gt Detector Detected Voltage on the Electric Power wem en 0 3 Voltage V 0 3dB Voltage V 000055000 00031 0 00726 eee 3 9
63. emp designers kits available KIT Model Mo of Price 4 NO Type Units in Kit Description per kit K1 ERA ERA 30 10 of each 1 2 3 49 95 2 20 10 of each 4 5 69 95 KI ERASM ERA SM 30 10 of each 15M 25 35 49 95 K2Z ERASM ERA SM 20 10 of each 45 55 69 95 K3 ERASM ERA SM 30 10ofeach 45 55M 65M 99 95 Ill Measuring Instruments Module Name AT6030D Spectrum Analyzer tracking generator TPR3003 3C DC Power AT RF3030 21 MMIC Amplifier Accessory SMA SMA 2 1 Accessory 7 Bamm SMB 2 V Experimental Procedures Caution Higher voltage than rated voltage can damage the circuit Take care not to apply high voltage than rated voltage to the 030 2 Amplifier modules ee Fig 13 6 MMIC Amplifier Gain Experiment 1 Connect the input and output of the AT6030D Spectrum Analyzer with cable and calibrate it Then display the relation curve of P f on the AT6030D 2 Adjust the the frequency of the AT6030D to 1500 SPAN 3000MHz In order to ensure amplifier in the signal amplification connect the 20dB Attenuator to the output of the AT6030D connect as following figure and then use cable to connect the input of the AT RF3030 21 MMIC Amplifier connect the output of the AT RF3030 21 MMIC Amplifier to the input of the AT6030D 3 Access the MMIC Amplifier adjust the DC Power to less than 15V Note higher voltage than rated 66 voltage
64. ength Lie Zy coti away after opening the terminal of the transmission line we That is 7 can 29 play a role of a capacitor C 1 Zo 6 I c dut Fig 7 4 Impedance of Open Transmission Line 3 Impedance Matching Using Stub As shown in Fig 7 5 if the characteristic impedance 40 50 when the load impedance is 41 4jXj the reflection occurs In this case if setting Z 50 by inserting a matching circuit as shown in Fig b Zr Zo So that the reflection coefficient becomes 0 and the matching is done The matching circuit uses lumped and distributed constant elements and also may use the complex form of the two elements The distributed constant element has small loss and its size can be reduced while it 1s difficult to find an element having a desired value For an instance of matching adjust the length of the transmission line so that a new impedance of 50 be obtained by adding a transmission line when Z 4jX Then if jX is connected again to the circuit in serial the overall impedance becomes Z1 504jX j X 50 and the matching is possible Because connecting the circuit in serial has a practical difficulty generally the matching is done by connecting in parallel 1 E cl b matching circuit Fig 7 5 Matching Unmatching Circuit Now the design method for a m
65. fficiency varies The problem is thinking about how to make the optimum current flow through the wire When the current flow through the wire having open terminals for RF the resonance similar to the LCR serial circuit in B occurs at a certain frequency 10 68 4 fa Current A B L C R Serial Resonance Circuit Fig 14 2 Antenna and Resonance Circuit As shown in Fig 14 2 A connect the RF ammeter to the middle of a straight wire having a length of 6 then connect the RF signal generator As the frequency increases gradually from the low frequency the current starts to flow through the antenna As it keeps increasing the current also keeps increasing so that it will have the maximum at a specific frequency fo When the frequency increases over that value the current now decreases The relation between the frequency and the antenna current is very similar to the LCR serial resonance characteristics shown in figure B Therefore a center fed wire having open terminals is resonant at the frequency fo In such a case the wire length is almost 1 2 of the fo wavelength Why the wire of the length 1 is resonant at RF having the wavelength twice longer That can be explained as follows Reflected Wave st C 4 5 Time elt Traveling Wave Traveling Wave Wire and Transmitting Lengih of Reflected Wave D Fig 14 3 Reason Why Electric Wave of Wavelength
66. for operation ta 3 GHz The HSMP 4820 diode is ideal for limiting and low inductance switching applications up to 1 5 GHz The 4880 15 optimized for low current switch ing applications up to 3 GHz The 286 series of general purpose diodes are designed for two classes of applications The first 15 attenuators where current coreumption is the most important design consideration The second application for this series af diodes is in switches where low cost is the driving issue for the designer The HSMP 385X series Total Capacitance and Total Resistance are typical specifications For applications that require guaranteed perfor mance the general purpose 383 series recom mended For low distortion HSIMP 38XX and HSMP 48XX Series Package Lead Code Identification SINGLE n COMMON SERIES ANODE 22 za a UNCONMECTED CATHODE PAR 25 DUAL ANODE DUAL CATHODE 14 attenuators the HSMP 38UX 381 series recommended For high performance switching applications the HSMP 380x seres is recommended A SPICE model is not available for diodes as SPICE does not provide key diode characteristic carrier lifetime Absolute Maximum Forward Current Ems Total Device Dissipation mW Peak Inverse Voltage EN Junction Temperature storage Temperature 65 to 150 Notes 1 Operat
67. g 14 13 4 Stub of Impedance 7 for Matching Impedance 74 72 If Z is the impedance of the microstrip line or the 50 9 coaxial cable and Z is the impedance of the patch antenna the characteristic impedance of the A 4 impedance converter connected to the patch and the microstrip line can be expressed as the following equation Z y ZZ V 501120 789 Fig 14 14 shows the 78 O 4 4 impedance converter and the single patch antenna included in the antenna set 4 PATCH IMPEDANCES ot QUARTER WAVE STB MPEDANCE a FEED MO aa TO THE COAKAL F PAICHES FOR THE 4 AL CABLE Fig 14 14 Single Patch Antenna Unit mm Ill Measuring Instruments Item Module Name AT6030D Spectrum Analyzer tracking generator AT RF3030 22 SMA SMA IV Experimental Procedures 1 First adjust the center frequency of the AT6030D to f 1500MHz SPAN 3000MHz Connect the input and output of the AT6030D Spectrum Analyzer with cable calibrate and record the display data on the AT6030D this data is the transmitting power of the antenna Lr 2 Connect all the lines to form a circuit as show in Fig 14 15 Connect the output of the AT6030D to one of the antenna 1 connect the input of the AT6030D to antenna 2 The distance between the two antennas L 25cm observing the receiving signal spectrumfromantenna 2 on the AT
68. ge P 2 Connect all the lines to form a circuit as show in Fig 5 3 Fig 5 3 Hybrid Ring Coupler Experiment 3 Connect the port lof the AT RF3030 9 Hybrid Ring Coupler module to the output of the AT6030D the port 2 of the AT RF3030 9 Hybrid Ring Coupler module to the output of the AT6030D the port 3 and port 4 with 50 9 load measure the input voltage Then Connect the port 4 of the AI RF3030 9 Hybrid Ring Coupler module to the input of the AT6030D the port 2 and port 3 with 50 9 load measure the input voltage P4 together it can measure the P3 5 1 Frequenc o power Output Lus ema Output P Output us ona p V eL dBm V _ dBm L V ea 4 Connect the other ports of the AT RF3030 9 Hybrid Ring Coupler module to the output of the AT6030D repeat step 3 and obtain the level of the relation isolation port V Review 1 What is the average coupling of the used coupler in the rage of 1 85GHz 2 4GHz In other words which decibel dB Coupler is it In addition what is the available frequency range of the coupler at the instance 2 What kind of problems are caused when the unused ports for the measurement are not matched 3 How much signals are detected from ports 2 3 and 4 when the signal having a frequency of 1 8GHz and a power of 10 dBm is input to port 1 shown in Fig 5 3 Calculate the value referring to lt Table 5 gt 4 Explain how the output signal
69. guided wavelength wavelength in the microstrip line 2 What is the wavelength in free space 3 In such a case what is the frequency D X 22X54mm 108mm VE uy For the Duroid 6002 substrate having a characteristic impedance of 50 The effective dielectric constant e 2 387 2 4 2x54mmxv 2 387 167mm 0 167m 37 e speedoflight 3x 10 9 _ 8 Ag ravelength 0 167 2 We 2 GHz Measuring instruments Item Module Name AT6030D Digital Spectrum Analyzer AT RF3030 23 microstrip line SMA 509 Load IV Experimental Procedures 1 Adjust the frequency of the AT6030D on some point of f 1O0MHz 3000MHz SPAN 0MH z Connect the input and output of the AT6030D Spectrum Analyzer with cable and calibrate it 2 Connect all the lines to form a circuit as show in Fig 8 5 the slider distance of the microstrip line more than 170mm Fig 8 5 Connect 50 Q oad experiment 3 Connect the 50 9 Load to the microstrip line move the slider module the VSWR 15 less than 1 05 displaying on the MMIC Amplifier 4 Connect Open to the microstrip line move the slider module VSWR is more than 10 displaying on the AT6030D 5 Connect Short to the output of the microstrip line then record the peak value and its position measured with slowly moving the probe from the left to the right ends Here take care to apply constant force to the probe during moving it The
70. he attenuator of a few dB 1s commonly used In the mixer it is used for improving the matching with Lo Local Oscillation Circuit and IF Intermediate Frequency Circuit For example if an attenuator of 3 dB is connected to a port having bad characteristic of return loss the return loss is improved by 6 dB 5dB gt 4 Adli Alt MN Ai p gt a Fig 6 1 improving Return Loss by Attenuator As shown in a of Fig 6 1 if a 3 dB attenuator is connected to the input terminal of the amplifier having the return loss of 5 dB the return loss is improved to 11 dB added by 6 dB As such by inserting in a circuit where the impedance matching 15 difficult the attenuator is also used for the matching improvement through forced reducing the reflective wave Fig 6 2 shows the appearance and the circuit configuration of type fixed attenuator 20 Oo 17 2 WV Wo 2 its p i UT Fig 6 2 T type attenuator When the attenuated value by an attenuator 15 L dB the resistance considering the matching be calculated by the following equations 25 For example the attenuator has the following calculated values Zo 50 9 N type Ry 296 5 2 17 6 2 T type 8 60 i R3 141 90 III Measuring Instruments Module Name AT6030D Spectrum Analyzer tracking generator AT RF3030 7 T Attenuator 5 5 IV Experimental Procedures
71. he diode without affecting the microwave line The following figure shows the specifications of the element used in the PIN diode switch module 42 Surface Mount PIN Diodes Technical Data Features Diodes Optimized for Low Current Switching Low Distortion Attenuating Ultra Low Distortion Switching Microwave Frequency Operation Surface Mount 50 23 SOT 143 Packages Single and Dual Versions Tape and Reel Options Available Low Failure in Time FIT Note l For more information sec the Surface Mount PIN Reliability Data Sheet Description Applications The HSMP 380X and 381 series are specifically designed for low distortion attenuator applica tions The HSMP 3824 series 15 optimized for switching applica tions where ultra low resistance 15 required The HSMP 38860 switch ing diode is an ultra low distortion device optimized higher power applications from 50 to 1 5 GHz The HSMP 389X series is optimized for switching applica tions where low resistance at low current and low capacitance are Absolute Maximum Ratings T 25 C Symbol Parameter required The HSMP 48x X series are special products featuring ultra low parasitic inductance in the SOT 23 package specifically designed for use at frequencles which are much higher than the upper limit for conventional SOT 23 PIN diodes The HSMP 4810 diode is low distor tion attenuating designed
72. hen the slope of skirt curve is steeper Fig 12 8 1s the frequency characteristic of the low pass filter for representing the insertion loss and the skirt characteristic S dB Fig 12 8 Frequency Characteristic of LPF III Measuring instruments AT RF3030 14 Band Stop Filter AT RF3030 15 Band high Filter 10dB Att I OdB attenuator 5 5 IV Experimental Procedures 1 First adjust the frequency of the AT6030D f Z1500MHz SPAN 3000MHz Connect the input and output of the AT6030D Spectrum Analyzer with cable and calibrate it Then measure the reference voltage 2 Connect all the lines to form a circuit as show in Fig 12 9 Connect the output of the AT6030D to one port of the AT RF3030 12 Loss Pass Filter module connect the output of the AT6030D to the other port of the AT RF3030 12 Loss Pass Filter module then measure the relation curve between the output voltage and frequency so that obtain the inserted loss L frequency response bandwidth and so 59 EJ FR E E Fig 12 9 Loss Pass Filter experiment 3 Repeat step 1 and 2 measure the parameters of the AT RF3030 13 Band Pass Filter or other filter as AT RF3030 14 Band stop Filter and AT RF3030 15 High Pass Filter V Results Table 12 1 Measuring Loss Pass Filter Loss Pass Filter Frequency Input Output Output Voltage Power dBm Voltage Power dBm Insertion Loss mW V
73. i 4 a L m mom m eA mm m E mmm i i i 2 GE LI E E L mom om L L E E 1 L L L m GE ee L i L a L i i i i daa asl i i i L L i i 1 i L i i L L i i a i L 1 E ct L 1 L L Fae m ems i 1 i 1 z omm om um db oae mo s s doe m m m m cm ca E ow xm m um ee ke Gm QS UN i 1 1 1 1 Liz memi n as 1 1 1 ssf i L a L SS mmo um tom om m Rm oom Gum m m Gm UM zm xm s ES dm dm E em mo m me mk E L n i 1 i mW 1 i L i 1 1 i i L i i L 1 i 1 i b
74. in a variety of types and shapes Before understanding the filter in various points of view first take a look at the filter by using a representative RF characteristic graph S parameter 48 Port Transmission Line Fig 12 1 Transmission Characteristics of S Parameter When the RF signal is applied to a common line all the RF signals are obtained as the output except for a tittle transmission line loss as shown in Fig 12 1 521 of OdB in the S parameter means that the ratio of the output to the input is unity That is since 10 log 1 0 the input power is transmitted to the output without loss 511 locating lower than 521 indicates that the reflected amount is very small S d8 Pass band Stop band Fig 12 2 S Parameter Transmission Characteristics of Low Pass Filter Such a case that 521 is maintained as about 0 dB and lt has a small value in Fig 12 2 means that the input signal of the corresponding frequency is transmitted to the output at its maximum and the reflection occurs at its minimum That is it corresponds to the frequency pass band Contrarily when 521 is small and 511 is about 0 dB it means the input signal of the corresponding frequency is mostly reflected and not transmitted which becomes the frequency stop band Passing a specific frequency to the output at its maximum without loss and reflecting the other frequencies are main roles of the filter Generally the filter can be divided into five type
75. inations of L and C are shown in Fig 11 1 n Ea 5 LE c S E E 0 4 1 i i cA tata i e i c Fig 11 2 Four Basic Resonance Circuits and Their Transmission Characteristics The resonance frequencies for the four circuits are 2 EC fd 21V LC Because the LC serial impedance is 0 at the resonance frequency f and the LC parallel impedance is 92 the signal is transmitted without loss for and b of Fig 11 1 While the signal is perfectly reflected for b and c Assuming f 1 5 GHz S parameters according to the frequency can be expresses as Fig 11 2 524 dB Fig 11 2 Frequency Characteristics of Resonator Having Loss OdB 68 pm Safa Fig 11 3 Bandwidth of Resonator according to Q Values little loss R exists in actual resonator where Quality factor is an important factor in determining the energy loss and the frequency selecting characteristics The Q factor can be defined as follows Oo dJe Resonance requency fa i Bandwidth Fig 11 3 shows the change of the frequency bandwidth according to Q values Smaller Q values mean the broad band while larger Q values mean the narrow band Similar to the LC resonance the resonance can occur in the microstrip line and the waveguide and some examples are illustrated Fig 11 4 33
76. ion in excess of any one of these conditions may result in permanent damage to this device 2 CW Power Dissipation at 29 C Derate to zero at maximum rated temperature 43 Same as 150 PIN Attenuator Diodes Electrical Specifications 25 C Each Diode Series Common Cathode Series Common Anode Common Cathode Test Conditions Vp Vor Measure Ip 10 pA Maximum Minimum Maximum Total High Maximum Series Ip 100 mA f 100 MHz Typical Applications for Multiple Diode Products RF COMMON Figure 22 Simple SPDT Switch Using Only Positive Current RF COMMON BIAS RF 1 Lo RF 2 Figure 24 Switch Using Both Positive and Negative Bias Current RF 1 RF COMMON RF 1 BIAS BIAS Figure 23 High Isolation SPDT Switch Dual Bias RF COMMON RF 2 BIAS Figure 25 Very High Isolation SPDT Switch Dual Bias Tepical for Pile Products CARY KW OT EF COMMOH HF 12 BIRS 1 BIAS 2 HI AS 4 3 ns Five 7 SPU Bibel Fizure 5 Tigh Isolation SPOT Switch Daal Bias Curren Measuring Instruments Item Module Name AT6030D Spectrum Analyzer tracking generator IV Experimental Procedures 1 Adjust the frequency of the AT6030D on some point of f ZI00MHz 3000MHz 5 7 Connect the input and output of the AT6030D Spectrum Analyzer with
77. is a device for sending or receiving the electric wave for the communication and usually called the aerial in Britain The antenna means a feeler of the insect and it originates from its role to capture the electric wave The aerial means in the air and the antenna is called the aerial due to this reason The transmission path in the wireless communication is not a wiring transmission line but free space It is the antenna that transmits and receives the signal in such free space as the terminal Voltage Electric Field Antenna time Fig 14 1 Function of Antenna Because the electric signal is transmitted as the flow of charges through a conductor charges cannot flow through a nonconductor such as free space However the electromagnetic wave cannot pass through a conductor and proceeds by forming the electric and magnetic fields on a nonconductor The antenna plays a role in inter converting the electric signal expressed as voltage and current and the electromagnetic wave expressed as the electric and magnetic fields as shown in Fig 14 1 By interconnecting the electric signal on a conducting line of the antenna and the electromagnetic field change outside of the antenna the electric electronic device can detect the electromagnetic signal in the air and vice versa 2 Resonance of Wire Even the shortest wire can radiate the electric wave proportional to the current intensity when the RF current flows although the radiation e
78. is almost the half wave length in the dielectric substance 0 49 X 4 That is why the opposite slots become the antenna excited to the opposite phases However the electric field radiating to two parallel slots becomes the same phase and is added in the normal direction of the antenna element broadside that is y direction Fa T w PLANE ELECTRIC Y CURRENT 5 a a ELECTRIC ELECTRIC FIELD 8 X LD hs q 2 Y Fig 14 8 Current Distribution and Common Type of Electric Field 72 5 Radiation Pattern When Two Waveguide Slots Are Arranged One simple method to calculate the characteristics of the rectangular patch antenna 15 comparing the patch antenna in Fig 14 7 with the waveguide slot antenna having 2 slots in Fig 14 9 The 2 slots waveguide antenna in Fig 14 9 is basically equivalent to the patch antenna in Fig 14 2 so the radiation patterns of these antennas will be identically shown To comprehend the radiation pattern of the 2 slots waveguide antenna it should be noted that the distance b is selected in such a way that the electric fields radiated from two slots have same phases At any point in the y axis the distance between two slots will be same X F Yz H PLANE A lt gt mq 2 PO WU Fig 14 9 Two Parallel Slots Waveguide Therefore the electric fields by two slots become the same phase and are added to each other in the far fiel
79. is resonant at Wire of 2 In Fig 14 3 the RF current travels along the vertical direction of the wire by the RF voltage e t which is fed to the O point of the wire This is called the traveling wave and its traveling speed 15 same as that of the electric wave radiating space After reaching the vertical point A of the wire the current is perfectly reflected by oo impedance so that it returns to the power source This is called the reflected wave Therefore the traveling and reflected waves continuously sent from the power source exist on the wire If the frequency of the power source 15 set to the resonance frequency the traveling and reflected waves 69 make a round trip on a wire between OA OA as shown in the figure When the polarity of the power source changes at the moment the reflected wave is returning to the power source the traveling and reflected waves on the wire becomes stronger In this case the relationship between the wire length And the resonance frequency fo 1s as follows E 150 MHz Ln 3 Excitation of Antenna When the wire is resonant the traveling and reflected waves of same size occur on the wire These waves interfere each other so that the voltage and the current on the wire will be as shown in Fig 14 4 The figure shows sizes of the voltage and the current at each part on the wire The current is maximum in the middle while minimum at both terminals In addition the voltage is opposite to
80. is subject to change without prior notice to improve its appearance specifications and performance Table of Contents EXPERIMEN 4 1 Theory and Experiment of VCO and 9 EAR pe 4 2 Ih ory and Experiment OF CI culatOL isiooasieceose 11 3 Theory and Experiment of Directional Coupler 15 4 Theory and Experiment of Branch Line Coupler nennen nnne 19 5 Theory and Experiment of Hybrid Ring Coupler sss eene nnne 22 6 Theory and Experiment of Aten al Or 25 7 Theory and Experiment of Matched Unmatched 28 8 Theory and Experiment of Measuring Standing Wave Ratio 11212 22 0000000000000 0 35 9 Theory and Experiment of PIN Diode S sese ope ue too poto use Ex eeu EHE 40 10 Theory and Experiment of Wilkinson Power Divider 1212 310000000000000000000000000000000000 47
81. l without damping in one direction and isolating the progress in the other direction as shown in Fig 2 1 It transports the signal from port 1 to port 2 with less than 3dB but damps all the signals from port 2 to port 1 Commercial isolators have a insertion loss transportation from port 2 to port 1 more than 15dB and a reflective index of about 0 0 1 Port Fig 2 1 Operation of Isolator Fig 2 2 illustrates operation of the 3 port circulator which is a key element for forming the isolator port input port port r EU mea EN E uem w m 24 Lieclric Power is Electric Power not transmissian M 1 Transmission d D E P E E at a Te i L 4 port port pert port Input port Input portz 2 2 Operation of 3 port Circulator port means an input or output terminal of the microwave signal A term of a terminal is used for low frequency circuits because just connecting two lines forms a connection However for the microwave a term of a port 1 separately used because a series connection of transmission lines wave guides coaxial cables or microstrip lines 1s necessary for a complete transmission of a signal As shown in Fig 2 2 when the power is input to port 1 the power is transmitted to port 2 but not to port 3 by the operation of the circulator That is when the power is input to a certain port the power is transmitted to either port
82. le II Theory Cross talk also exists in the low frequency region but its effect is not significant because of the low frequency As the frequency increases each line becomes an antenna to radiate the electron wave energy and affects the neighboring lines As such an interaction between energy of lines is called coupling and a coupler is made based on the coupling phenomenon The coupling is controlled to the desired level by adjusting the interval and the length between the neighboring lines Main applications of the coupler are 1 For power sampling 2 For power dividing Power sampling means detecting a signal of very little amount from the original signal When the properties of the actual signal needs to be checked from the line flowing an RF signal the coupler is used for detecting the power without disturbing the flow of the signal With the detected power of little amount the signal information its properties or power level of its actual flow can be identified In fact itis commonly used to identify the power instead of the signal information or its properties For example the detected power by a 30dB Coupler is 17dBm it can be seen that actual power of 17 30 13 dBm flowing through the circuit Fig 3 1 shows a coupler for power sampling Coupler Inaut A Coupling Fig 3 1 Power Sampling It should be noted that if a 30 dB coupler samples 1 1000 of the actual power the actual power would be de
83. n he 4 Receiver Receiver Fig 2 4 Duplexer Using Circulator Circulator can be formed with using a waveguide as shown in Fig 2 5 a but the most commonly used circulator is a SMD Surface Mount Device type Ferrite circulator shown in Fig 2 5 b This circulator uses a soft magnetic ferrite which arranges its magnetic domain according to the external magnetic system Each port is arranged with a 120 interval and the basic structure is illustrated in Fig 2 5 stripline type a Waveguide Circulator CU Pam T lt ZU 2 CER D CUN am 3 Eo i pL 4 P mU w wo d Drax b Microstrip Circulator Fig 2 5 Structure of Circulator 12 Ferrite 18 placed at the top and bottom of metal Plates having three ports and a fixed magnet is located outside the ground metal plate The fixed permanent magnet is used for causing the magnetization of ferrite and only ferrite without a permanent magnet may be used In an attempt to explain its operation Fig 2 6 a illustrates a Case the power is input to port 1 out of 3 ports Strip disk operates like a resonator so that the electric system exists perpendicular to the disk and the magnetic system on the surface of the disk Therefore Weaker signals than that of port 1 are identically detected at port 2 and port 3 pom nou ra _ Part 2
84. nd a wave propagating A 4 from in the clockwise direction reach 8 These two waves have same phase so that they are output at 8 with combined with each other From the A point of view D 15 located at a position which is separated 3 4 from A both in the clockwise and the counterclockwise directions so that two waves having same phase are combined and output At a wave propagating 2 from A in the clockwise direction and a wave propagating A from A in the counterclockwise direction are reached These two waves have opposite phase Therefore C becomes an isolation port where no output is detected Therefore while C is a negligible port the circuit has a symmetric arrangement of 8 and D ports from A point of view The 22 power input to A is equally divided to B and D not as equally divided to and D with having same phase as the input signal is applied to C Instead it is equally divided to B and D with having opposite phase As such characteristic of the Hybrid Ring Coupler is explained in brief In fact matching of each port is also an important factor so the literatures should be referred for the detailed design method III Measuring Instruments Module Name AT6030D Spectrum Analyzer tracking generator AT RF3030 9 Hybrid Ring Coupler SMA SMA 509 load 2 IV Experimental Procedures 1 Connect the input and output of the AT6030D Spectrum Analyzer with cable and calibrate it Then Obtain the refer volta
85. nect the input and output of the AT6030D Spectrum Analyzer with cable and calibrate it Then measure the refer voltage 2 Connect all the lines to form a circuit as show in Fig 11 6 Connect the output of the AT6030D to one port of the AT RF3030 16 Ring Resonator module connect the output of the AT6030D to the other port of the AT RF3030 16 Ring Resonator module then measure the relation curve between the output voltage of the AT RF3030 16 Ring Resonator module and frequency Fig 11 6 Ring Resonator experiment 3 Measure the resonator frequency inserted loss L bandwidth and so on V Review 1 Plot the frequency characteristics of the ring resonator with using the measured values 2 Find the resonance frequency fr and Q value of the ring resonator with using the measured values 3 Does the circumference of the actual AT RF3030 16 module agree with 6 value of the ring resonator calculated from the measured resonance frequency f Here 2 4 4 Examine the waveguide resonator 55 12 Theory and Experiment of Low Pass and Band Pass Filter I Objective To comprehend the principle of the filter with the low pass filter and the band pass filter using the microstrip transmission lines II Theory The filter allows for passing a certain frequency and attenuates the others out of various frequency components It is one of the most frequently used circuit 1n the entire RF systems and can be formed
86. nect the microwave signal from one transmission line to another II Theory The microwave switch can be divided into the mechanical and the electric switches The electric switch mainly uses the PIN diode The PIN diode is commonly used not only for the switch but also for the variable attenuator the limiter and the modulator 2 Bigs my e P E Reverse 2125 PIN Diode b Equivalent Circuit of PIN Diode Fig 9 1 Structure of PIN Diode The PIN diode in formed by a junction of the semiconductor I Intrinsic area having high resistance with hardly doped between the PIN junction as shown in Fig 9 1 a When the forward current flows through the diode the electron and the hole are inserted to the area but they cannot recombined entirely so that part of them kept as the stored charges Due to these charges the resistance of the 1 area becomes lower It shows the same rectifying characteristics as the common diode up to 100 MHz but shows the characteristics of the variable resistor at higher frequency This is due to time necessary for passing the stored charges and the 1 area and it shows the resistance of about 1 at the short state according to the forward DC voltage The equivalent circuit of the PIN diode at the forward and reverse bias conditions 1s shown in figure b with excluding the inductance of the lead and the parasitic capacitance of the package Rp is the eq
87. o the ultrahigh frequency As a result it can be mainly used for the calibration of a measuring instrument which requires the wide frequency range However it can be used in the broadband while the insertion loss becomes larger because it uses the resistor Fig 7 10 Broadband Resistance Impedance Transformer Fig 7 10 is a modified type of the type attenuator and the resistors symmetrically arranged in the 32 type attenuator are removed Because the input and output impedance of the matching element are not symmetric two resistors positioned at both sides should not be symmetric III Measuring Instruments Module Name AT6030D Spectrum Analyzer tracking generator AT RF3030 5 Unmatched Load AT RF3030 23 SMA SMA IV Experimental Procedures 1 Adjust the frequency of the AT6030D on some point of f 100MHz 3000MHz SPAN 0MHz Connect the input and output of the AT6030D Spectrum Analyzer with cable and calibrate it 2 Connect all the lines to form a circuit as shown in Fig 7 11 That is connect the output of the AT6030D to the input of the AT RF3030 23 microstrip line module connect the output of the AT RF3030 23 microstrip line module to the AT RF3030 6 Matched Load connect the output of the slider to the input of the AT6030D move the slider and then observe the changes of the Spectrum line and measure the VSWR of the AT RF3030 6 Matched Load toa 208 Fig 7 11 connec
88. or matching Zy to Zo 7118 determined by 31 eircuitz B Fig 7 8 Matching Using 4 Transmission Line If Zi 2100 for matching the line of 7 50 9 71 is determined by Z 50 100 70 7 That is if the characteristic impedance of the 4 line is Z 270 7 9 the overall impedance is mat ched to ZiN 50 0 Verifying the result when Z 270 7 9 Zm becomes _ 10 71 aw 10 9 and the circuit is matched Such a method is called matching using the 4 transmission line In order to match an arbitrary complex number load instead of the resistive load connect another transmission line first to convert the complex number to the resistive load as shown in Fig 7 2 then perform the 4 4 matching However it has disadvantage that the bandwidth becomes very narrow Fig 7 9 shows an example of matching by means of the microstrip transmission line X c al 1 2 l 1 a 1 rr Quarter wave Transformer Short Stub Fig 7 9 Matching Circuit Using Microstrip Transmission Line 5 Resistance Impedance Transformer The circuit shown Fig 7 10 is a input output matching circuit using the resistor This circuit can be assumed that the minimum amount of attenuation is achieved by performing an appropriate matching from inserting the attenuator between different impedance terminals The characteristic of the resistance impedance transformer 15 that it can match the broadband from the DC t
89. pacitor to remove the AC noise Therefore if all the capacitors in Fig 9 3 are opened and the inductor is short the DC equivalent circuit as shown in Fig 9 4 a can be obtained On the contrary if all the capacitors are short and the inductor is opened the AC equivalent circuit as shown in figure b can be obtained When the forward and the reverse voltages are respectively applied to V2 and turns ON and DI turns OFF so that the signal from port 1 to port 2 is transmitted while the signal is not transmitted to port 3 Of course port 2 and port 3 are isolated Or in the opposite way if the reverse and the forward voltages respectively applied to V2 and V3 the signal from port 1 to port 3 15 transmitted while the signal is not transmitted to port 2 Fig 9 3 Circuit Diagram of SPOT Switch 4 EAS x Ar 2125 wur 38 a DC Equivalent Circuit Port Port Porta b AC Equivalent Circuit Fig 9 4 DC and AC Equivalent Circuit of Switch Fig 9 5 Switch Using Microstrip Line The PIN diode SPDT switch shown in Fig 9 5 is a real circuit formed by inserting the diode in serial to the microstrip line The DC bias V5 and V3 is supplied to 4 of higher impedance In the microwave signal point of view one end of this line has an impedance of 0 grounded but an impedance of go at the 4 point Therefore the DE bias is supplied to t
90. pply Current mAd 1 30 Output Power 6 0 420 48 Tuning Port Capacitance p 47 3dB Modulation Bandwidth Hz 300 Fig 1 4 Specification of the SZ COM V6009001 2350 VCO 2 Diode Power Detector Power is defined as a consumed amount of energy per unit time It is hard to measure the voltage and current of the microwave so usually the power is measured The power of the microwave can be divided into three levels Low power mW 0dBm or lower Intermediate power 1mW 10W 0 40dBm High power 10W 40dBm or higher A power meter is necessary to detect the power of the microwave The power meter can be divided into a calorimeter bolometer or microwave diode type When the Oower is low a bolometer type is used because error caused by the temperature increase of water may be large The bolometer is inserted to the wave guide and the microwave is absorbed Then the power is obtained from the resistance value after equilibrating the changed resistance by means of the bridge circuit Commercial power meters have this configuration Using a calorimeter the power is measured from the temperature change of water by absorbing the microwave to water Various methods are required to increase the sensitivity and it is useful for the power measurement higher than a few Watts A diode power detector converting the power of microwave into the proportional
91. r functions When the power is required to be divided equally into two paths the transmission line the power be divided equally using the transmission line of the T junction structure as shown in Fig 10 2 a However because the T junction line has no loss and it cannot be calibrated or converted when there exists an impedance difference between ports three ports in the T junction line cannot be matched perfectly To solve this problem of the T junction a resistor is used for inserting between two paths as shown in Fig 10 2 b outputi output input e input outputz output a Simple T junction Line b When Balance Resistor is added Fig 10 2 T junction structure For dividing power with perfectly matched state in the radio frequency RF region the impedance converting and balance between ports are required The Wilkinson power divider is made with considering various characteristics of the radio frequency RF Fig 10 3 shows the structure and impedance relationship of the Wilkinson power divider 47 output mput 2 70 UN gt output2 4 Fig 10 3 Structure and Impedance Relationship of Wilkinson Power Divider 2 Wilkinson Power Divider The Wilkinson power divider 15 a three port divider having loss made in such a manner that the output ports are isolated and all the ports are matched This divider has no loss when the output port is matched but only loss of the reflec
92. reflected wave of the voltage that is the voltage reflection coefficient Gamma 18 4123 42114 Fj Ert Where V is size of the reflected voltage V size of the incident voltage Z the characteristic impedance of the line and 41 the load impedance Here the rato of incident power to reflected power is P Y where is power of the reflected wave and P indicates power of the incident wave 35 Incident wave AN Incident wave transmission wav reflected wove reflected wave i ave 13 22 Fig 8 2 Electric Wave in Mismatched Transmission Line The incident and the reflected waves simultaneously exist in the line but actually they are observed as a mixed form Fig 8 3 shows a process forming the standing wave from mixing two waves in a case of perfect reflection which is 1 due to the short of the load In the figure a is the reflected wave b 1s the incident wave and c is a waveform resulting from mixing the reflected and incident waves As time goes on the size changes but intersections with x axis are fixed n 5 un D 3 1 E E D x UM 1 RE a th CX y X gt e 5 1 28 5 E s L 2 P E ES b 1 1 E 1 I l
93. rmed using a branch line it increases the capacitance value so that a branch line coupler is the same as a directional coupler Fig 4 2 shows a 90 Branch Line Coupler fr Sees Arr T n Fuat 3 4 Fig 4 2 90 Branch Line Coupler 90 Branch Line Coupler is frequently used as a equally dividing couple having a coupling of 3dB By using this a coupler having a relatively high coupling can be made easily Branch Line Coupler has an advantage of simple design but also has a disadvantage of large circuit size because it is made using a 19 transmission line 90 Branch Line Coupler basically operates as follows If all the ports of 90 Branch Line Coupler in Fig 4 2 are matched when the signal is input to port 1 port 2 and port 3 show an output having a phase transition of 90 while there is no output in port 4 90 Branch Line Coupler has both vertical horizontal symmetry and the output port and the isolation port are placed at the opposite side and at the top bottom of the input port respectively That is it operates in a fully symmetric structure which shows the output in port I and port 4 and no output in port 3 when the signal is input to port 2 The coupling is determined by a Shunt Arm to Series Arm ratio where the impedance can be determined by the following equation Pa Z VIZ j 2 2 al Hay ye P a i 1 y d b l For a commonly used 3dB Coupler 2 because P gt
94. s according to the frequency pass band 1 Low Pass Filter 56 This filter is a basic type of all the filters The LPF Low Pass Filter blocks the radio frequency signals and transmits only the necessary low frequency signal within the block frequency It is formed as the simplest form and other types of filters can be made by converting this basic form in variety This type of filter 15 fairly used in the various areas such as removing the low frequency ripple removing the radio frequency spurious suppressing the harmonic and various detections H f 098 308 2 High Pass Filter The HPF High Pass Filter has a characteristic that blocks the low frequency signals and transmits only the radio frequency signals higher than the necessary bandwidth higher than the block frequency The biggest problem of the HPF is that it cannot be formed using the distributed element 4 4 i 1 J 3 Pass Filter f The BPF Band Pass Filter transmits signals the desirable bandwidth while it blocks signals in the undesirable bandwidth When the transmission terminal receives or transmits the exactly necessary frequency out of many frequencies the BPF 15 used 4 Band Stop Filter or Band Reject Filter Hf h f In contrast to the BPF the BSF blocks signals in the desirable bandwidth while it passes signals in the other bandwidth This filter is mainly used for blocking inflow of the
95. s of ports 1 3 and 4 would change if the input signal is connected to port 2 5 Explain the definition and principle of the Hybrid Ring Coupler 6 Find and explain the example of an application circuit using the Hybrid Ring Coupler 24 6 and Experiment of Attenuator I Objective To comprehend the operational principle and purpose of Attenuator using AT RF3030 7 Attenuator module II Theory In brief the attenuator can be defined as a device for reducing amplitude of the electric signal Because the attenuator only reduces the signal amplitude without changing the signal waveform all the input output impedances of the attenuator should be matched with the characteristic impedance of the transmission lines The attenuator is mainly used for three purposes in a circuit that is the level control the stability improvement and the matching improvement Here if one of the stability or the matching is improved the other also improved together In addition to the control of power level the attenuator is also used for the output terminal of the oscillation circuit the LO input terminal of the mixer the output terminal of IF or the output terminal of the amplifier The oscillation circuit is affected more or less by the load connected to the its output Here the attenuator is used for reducing the effect of the load so as to improve the stability of the frequency and the output level in the oscillation circuit In general t
96. s the resonator that determines the frequency The resonance implies a selectivity of a certain frequency so the resonance frequency can change by adjusting the property of the resonator Operating Temperature Range 40 to 70 degrees Storage Temperature Range 55 to 125 degrees C Voltage Vde Vtune Voltage Vdc Pirincin ue Fig 1 2 Oscillator Circuit Rs 21 La 1010 Symbol b Reverse Bias Equivalent Circuit Fig 1 3 Varactor Diode That can be achieved by using a varactor diode as shown in Fig 1 3 The varactor varactor variable capacitor diode is manufactured from semiconductors and it is a variable capacitor having variable values according to applied voltages When the diode is reverse biased at both sides of the p n junction is formed a space charge region which forms a depletion region The width of the depletion region is controlled by the reverse bias and the transition capacitance is generated by isolated space charges As the voltage of the reverse bias increases the width of the depletion region also increases which results in the decrease of the transition capacitance Basically the resonance frequency changes according to the inductance L and the capacitance C Therefore adjusting the inductance L or capacitance C can change the property of the resonance part The resonance
97. smission line it can be seen that the impedance varies according to the length of the transmission line The load at x 0 1 71 but as Increases to 7 5 27145 205 Even if the load impedance Zi is pure resistance 7 Z3 complex numbers Combined type of the resistance and the capacitance or the inductance components In other words the impedance can be changed to the desired value by adding the transmission line to the load and adjusting its length For reference such change of the impedance is repeated every 2 of the line length 2 Impedance of Short or Open Transmission Line When the load at the terminal of the transmission line is shorted or opened the overall impedance becomes the capacitive or inductive load according to the length of the transmission line As shown in Fig 7 3 when the impedance 7 is measured at a point of length l away after shorting the terminal of the transmission line having a characteristic impedance of Zo Z jZ tan j o L However the length C should be 0 lt 4 and 22 1 That is 7 can play a role of an inductor L Zo 0 lt As such an element which has an inductance component by using the transmission line 15 called the distributed constant element BU Zs ja Fig 7 3 Impedance of Short Transmission Line In the same manner as shown Fig 7 4 when the impedance is measured at a point of l
98. t the matched load 3 Repeat the step 2 measure the VSWR when the open and short of the load 4 Change the AT RF3030 6 Matched Load to the AT RF3030 6 Unmatched Load and then repeat the steps 2 3 The two measure methods are same just the VSWR of the AT RF3030 6 Unmatched Load is bigger When the VSWR is more than 5 measure with the method of the double the minimum obtain the index d at two times the minimum distance between two points and waveguide wavelength and then calculate the VSWR as following formula V Review 1 Identify the relationship between F and the return loss 201ogI Return Loss dB 2 Describe advantages and disadvantages of matching by comparing the stub matching with the 33 matching using the 4 transmission line 3 When the load impedance is 509 matching using the 4 transmission line is tried What is the characteristic impedance and length of the A 4 transmission line Here the frequency is 1 GHz and the relative dielectric constant s 1s 1 4 Calculate the load resistance expected to be 100 by using the measured reflection return loss What is the accuracy and what is the reason if the accuracy is not good 5 10log oP 15 used in a calculation for converting the power to value in dB and 2010g oP is used for converting the return loss to value in dB Why are the coefficients used in these equations different 34 8 Theory and Experiment of Measuring
99. ted power The Wilkinson power divider can be fabricated to divide power arbitrarily and can be manufactured in the microstrip or stripline type Here an equal division 3 dB 1s targeted and the Even odd mode analyzing method is used as an analyzing method which analyzes by making two simple circuits with the application of the symmetric and unsymmetric signals to the output port As shown in Fig 10 4 in order to analyze the divider with the principle of superposition by the even mode and the odd mode if the 2 V power having the internal impedance 40 is applied to port 2 and only Zo is terminated for port 1 and 2 it can be considered as a superposition of the even and odd modes as shown in Fig 10 5 a and b Such an Even Odd mode analyzing method is also used for analyzing the directional coupler the branch line coupler and the hybrid ring coupler and also applied to the analysis of the differential amplifier which is commonly used for the input terminal of the operational amplifier in an electric circuit fo Ports mU Po 42 30 v2 E E ra _ Ld ud MAI T Furt NJ ro aE Fig 10 4 Wilkinson Power Divider Having Symmetry In Fig 10 5 resulting equation for each terminal by the superposition of two modes from the applied input to port 2 is as follows Voz VoerVoo 1 Vi Vie Vio j0 707 V2e V 0 48 Port Wraymmiatrict short Port b
100. th figures and E show the RF antenna having length but the current direction 71 and voltage polarity change because the supplying points are different Also the radiation characteristics especially the directionality becomes completely different 4 Characteristics of Rectangular Patch Antenna FEED cu Fig 14 7 Basic Rectangular Microstrip Antenna Fig 14 7 shows size of the basic rectangular microstrip patch antenna The conductance of the antenna is a function of the width a and the resonance frequency 15 a function of the length b bz 0 494 0 49 T7 where A ais the wavelength in the dielectric substance o is the wavelength in free space 6 15 the relative dielectric constant of the substrate Because of the dielectric constant and the change of the supplying inductance it needs to define the accurate length of the patch for the measurement Fig 14 8 shows the current flowing inside of the patch and the electric field around it The electric field mainly exists around the patch connected by the supplying lines and the opposite edges The electric field 1s caused by the radiation characteristics of the antenna A wave radiated from the antenna shown in Fig 14 8 has the horizontal polarization characteristics That is the horizontal direction means E plane x y plane while the vertical direction means H plane y z plane The interval b between two edges of the patch antenna
101. the size of output signal relative to the input signal That is if the size of output signal becomes ten times larger than the input signal the gain of this amplifier will be 10 dB Contrarily the maximum output power represents how much power can be operated at the output terminal of the amplifier and it means the maximum power W dBm to be output Therefore sizes of the maximum output power and the gain should be regarded as different concepts The following illustrates how to increase the gain by the dependent connection When the gain cannot be obtained with one amplifier many amplifiers are connected for obtaining the gain 12d8m 20d8m BdBm 40dBm x10 20 16001 1068 134 352ddB As the gain of the amplifier increases the output also increases When 12 dBm 15 applied to the input of the amplifier having total gain of 32 dB the output becomes to 40 dBm 10 W so that it 1s beyond the acceptance of the normal amplifier Therefore the maximum available power of the terminal amplifier should be increased to more than 40 dBm in order to obtain the desirable output and gain In order to increase the maximum output power two amplifiers are connected in parallel at the terminal as shown in Fig 13 1 so that the desirable output can be obtained while keeping the gain constant If necessary more amplifiers can be additionally connected in parallel 61 10dBm Output with the connection of
102. uit M4 co MA ta we M ee 5 i Not me i O e B D a ase 226 age EL 2 T Fig 5 2 Hybrid Ring Coupler As shown in the figure all the intervals between ports 8 and C D are 4 while only that between ports A D is 3 4 It will be explained how the input and output relationship of each port is defined due to this configuration When a signal is input to C a wave propagating about 52 4 from C in the clockwise direction and a wave propagating about 4 4 from C in the clockwise direction reach B In addition because these two waves have same phase they are output with combined with each other Also at D like at B two waves propagating in the clockwise and the counterclockwise directions are output with combined with each other At A a wave propagating A from C in the clockwise direction and a wave propagating 2 from C in the Counterclockwise directions are reached These two waves have opposite phase so that they cancel each other Therefore A becomes an isolation port where no output is detected Accordingly while A is a negligible port the circuit has a symmetric arrangement of B and D ports from C point of view That is the power input to C is equally divided to B and D with having same phase When a signal is input to A a wave propagating about M4 from A in the counterclockwise direction a
103. uivalent resistor for the forward voltage has a value of 0 1 and decreases as the forward current increases RR 15 the reverse resistor having a value of about 10 1 C is the reverse junction capacitance having a value of 0 1 2 pF and decreases as the reverse voltage increases 40 SPST Switch b SPDT Switch c SPST Switch d DPDT Switch Fig 9 2 Various Switches Fig 9 2 shows various switches using the PIN diode A portion shown as a dashed line in the figure indicates the PIN diode Figure a is a switch which connects or disconnects one signal to or from another port and called the SPST Single Pole Single Through switch Figure b 16 the SPDT Single Pole Double Through switch and according to the purpose various switches such as the SP3T and the DPDT Double Pole Double Through switches as shown in figure c and d can be formed Fig 67 shows the circuit diagram for the SPDT switch using the PIN diode where the path is selected according to two biased voltages V5 and The element 15 HSMP 3824 of Hewlett Packard Ltd which has a common cathode type of two diodes in one package The forward bias is supplied through the resistor Rg for controlling the forward current so that it prevents the PIN diode from damaging due to the excess current In such a case the current flows through Rg L DI L to the ground and the blocking capacitor Cg is connected to prevent from flowing to each port Cp is the bypass ca
104. ventually P dB means the power at a point where the gain is decreased by 1Db 4 has various meanings depending whether the actual amplifier is used for the linearity purpose or not but basically it can be regarded as the maximum linear input output power stably available for that amplifier When using the amplifier in normal condition use it up to the range a few dB lower than the 4 point in order to have the table characteristic Fig 13 3 shows the input output at the point where the gain 15 decreased by 1 dB than the maximum power point of the amplifier 62 For Unsaturated and ideal Linear Amp Output Power 1 2 2 d Actual Output Power Dynamic Range um dud Minimum Detectable Power 2 2 Noise Baseline Input Power Input Prag Fig 13 3 Power Characteristic Curve of Amplifier 3 IMD Intermodulation Distortion When a frequency fi is applied to the non linear amplifier harmonics such as 2 fj 3 4 fi and so on occur at the output Similarly if many signals are simultaneously applied to the amplifier the intermodulation distortion among these signals are caused which is call the IDM Intermodulation Distortion The IMD partly occurs in the passive element having very high output and mainly occurs in the active element especially the amplifier The power amplifier having drastically decreased distortion 15 called the LPA Linear Power Amplifier 4 IP3 Third Order Intercept
105. y 3 Change the Viune voltage of the AT RF3030 1 VCO module from to 20V Then measure outputting frequency and power values with the AT6030D and record in Table I gt Caution Higher voltage than rated voltage can damage the circuit Take care not to apply higher voltage to the Vec and Viune terminal of the AT RF3030 1 VCO module 4 Plot a graph by using results of Table 1 Keep these results because they are further used as basic data for all the experiments presented in this book 5 Adjust the Viune to some value and then use AT6030D to observation frequency and two tuning wave V Results Table 1 Output Measurement of VCO Viune V Frequency GHz Output Voltage V Output Power dBm Output Power W Record frequencies GHz output voltage V output power dBm output power W with the reference of the output frequency table according to the tuning voltage in Table 1 gt VI Review 1 Explain the definition of the VCO and the principle of the oscillation 2 Explain about which can control the VCO output frequency 3 Explain the types of the detector and detecting methods 10 2 Theory and Experiment of Circulator I Objective To comprehend the purpose and operational principle of a circulator by applying signal to each port with the AT RF3030 3 Circulator module II Theory 1 Isolator and Circulator An isolator is a circuit used for transporting signa

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