DESIGN, MANUFACTURE AND TEST TECHNIQUES FOR MULTIPACTOR FREE RF DEVICES. Troy Rodriguez, Khosro Shamsaifar, James Haas

Transcription

1 DESIGN, MANUFACTURE AND TEST TECHNIQUES FOR MULTIPACTOR FREE RF DEVICES Troy Rodriguez, Khosro Shamsaifar, James Haas Sierra Microwave Technology One Sierra Way, Georgetown, TX 78626, USA 1

2 INDEX Introduction Waveguide Circulator (Design, Analysis and Test for Multipaction) Lumped Element Filter (Design, Analysis and Test for Multipaction) Isolator-Combiner (Design, Analysis and Test for Multipaction) 2

3 INTRODUCTION Examples of high power RF devices that were designed and successfully tested for multipaction at Sierra Microwave will be presented, Including: A WR112 waveguide circulator in X-band tested to 3000 Watts peak A VHF lumped element band pass filter tested to 80 Watts peak An L-band coaxial isolator-combiner tested to a combined output power of 2000 Watts peak The design approach, multipaction mitigation methods, test methods and test results for each of these parts will be presented and discussed 3

4 WR112 High Power Circulator NuSil RTV (CV ) 2 mil bond line between Ferrite and W/G Housing. High power waveguide circulator covering 7-9 GHz Power handling requirement : 1000 Watts peak (500 Watts average) Device tested for multipaction with 3000 Watts peak (600 Watts average) Teflon spacer between Ferrites for matching Gaps between waveguide, Ferrites and Teflon Insert filled with RTV to prevent Multipaction 4

5 CIRCULATOR MULTIPACTION ANALYSIS Multipaction Analysis Performed Using SPARK3D 1 Electro Magnetic Field Distribution Obtained by HFSS Uniform DC Magnetic Field Used in Circulator Operation Included in the Analysis The Presence of Magnetic Field Significantly Reduces Multipaction Threshold It has been shown 2 by analysis and verified by testing that parallel magnetic fields inhibit electron diffusion which results in lower breakdown voltage and lower Multipaction threshold 1 SPARK3D is a SW Developed by Aurorasat 2 A.A. Hubble et al, Diffusion-Limited Resonant Electron RF Breakdown, MULCOPIM

6 Circulator 3-D Model used in Multipaction Analysis with SPARK3D 6

7 Multipaction Analysis of the Ferrite Region - DC Magnetic Field Included Ferrite Region Ferrite Region DC Magnetic Field: 0 Gauss Breakdown Threshold: Watts DC Magnetic Field: 500 Gauss Breakdown Threshold: 3781 Watts Ferrite Region Ferrite Region DC Magnetic Field: 1000 Gauss Breakdown Threshold: 3344 Watts DC Magnetic Field: 1500 Gauss Breakdown Threshold: 3031 Watts 7

8 Multipaction Analysis of the Ferrite Region - DC Magnetic Field Included DC Magnetic Field: 0 Gauss Breakdown Threshold: Watts 8

9 Multipaction Analysis of the Ferrite Region - DC Magnetic Field Included DC Magnetic Field: 1500 Gauss Breakdown Threshold: 3031 Watts 9

10 The Presence of Magnetic Field Significantly Reduces Multipaction Threshold DC Magnetic Field (Gauss) Multipaction Threshold (Watts) The operating point of DC Magnetic Field between the Ferrites is approximately 1500 Gauss 10

11 CIRCULATOR MULTIPACTION TESTING Test Parameters Parameter Setting Notes Frequency 7.00 GHz Power 3000 W peak 600 W average (150W+450W CW) Pulse Width 100 µs, 5% duty factor Pressure Temperature <1.0e-5 Torr. -10 and +23 Deg. C Electron Source Cs 137 Source, 3 sources, 10 µc each Sample Rate Detection Methods 50 KHz Input Return Loss, Through Power Input/Output Third Harmonic Current Probes (all ports) Instant Change in any two parameter and/or anomaly in Pico ammeters # of Samples Tested 20 11

12 CIRCULATOR MULTIPACTION TESTING Test Conditions Test Set-up calibrated prior to Multipaction testing Multipaction standard used to verify the test set-up Power level ramped from 1600 Watts peak, 315 Watts average to 3000 Watts peak, 600 Watts average, in 200 Watts intervals with 5 minutes dwell at each level. 30 minutes dwell at maximum power of 3000 Watts peak, 600 Watts average Forward, reflected and output powers continuously monitored and recorded Third harmonic signals at input and output continuously monitored and recorded Current Probes (Pico ammeters) placed at all ports through the vent holes to detect possible anomalies Several thermocouples placed on DUT and base plate to continuously monitor and record the temperature. Thermal vacuum chamber pressure continuously monitored Visual Inspection after multipaction testing using a microscope at 10x magnification and RF test according to the test plan 12

13 CIRCULATOR MULTIPACTION TESTING GPIB To Computer RF Shutdown Switch (not used for standard test) Agilent Synthesizer E8257C 3dB COAXIAL HYBRID Merrimac, QHM2M-6G or Midisco, MDC7226A Pulse Modulator 100 µsec Pulse Width 5% Duty Factor Variable Attenuator Arra, AR4824 Variable Phase Shifter ATM P1607D THIS EQUIPMENT DISCONNECTED DURING THE HP TVAC TEST TWT Ametek/IFI PT86-6KW-TMS (Peak Amp) TWT Ametek/IFI T P (CW Amp) To TMX D06 GPIB To Computer HP WR112 Load SMT High Power WR112 Circulator SMT SM24475 High Power WR112 Circulator SMT SM24475 HP WR112 5dB Hybrid SMT SM80219 To Computer Top Temp To TMX D03 Bottom Temp To TMX D04 To Shutdown Switch, Ch 6 To Shutdown Switch, Ch 5 To Shutdown Switch, Ch 2 To Data Acquisition Unit Ch 301 (DC Voltage) To TMX B06 To TMX B02 To TMX B01 To Shutdown Switch, Ch 7 Chamber Pressure To TMX B03 To Data Acquisition Unit, Ch 111 High Power WR112 LP Filter SMT SM41354 J1 Temp To TMX D05 J2 Temp To TMX D06 J3 Temp To TMX D07 Baseplate Temp To TMX A08 GPIB Data Acquisition Unit Agilent 34970A Fluid Temperature Huber Unistat 705 Vacuum/Temperature Controller Unitronics V350-PLC Picoammeter (See Figure 7) Picoammeter (See Figure 7) Picoammeter (See Figure 7) Alarm Tempco TEC-90 Test Computer 5 DUT Thermocouples, Type T Baseplate Thermocouple, Type T Ch 301 from Vac/Temp Controller Ch 111 from Huber Unistat Ch 109 Baseplate Thermocouple Chamber Controller Thermocouple Shutdown Thermocouple USB GPIB 3X 10 µc SOURCE CS137 (One on each port) Thermal Vacuum Chamber LACO VC-2000 Multipaction Test Set-up THIS CONNECTION FOR HP TVAC ONLY Variable Attenuator Arra, AR4824 To Shutdown Switch, Ch 4 To TMX B05 USB To Computer GPIB To Computer Spectrum Analyzer Agilent N9030A HP WR112 Load SMT 3rd Harmonic 30dB Attenuator Fairview Microwave SA18N-30 or Equivalent Harmonic Tee SMT SM dB Forward Reverse 30dB Crossguide Coupler IFI DDCC-WR112-50F-30R WR112 Window J1 DUT J3 J2 Base Plate Chamber Thermal Platten Forward 50dB Reverse 30dB Harmonic Tee SMT SM41355 HP WR112 Load SMT 3rd Harmonic 30dB Attenuator Fairview Microwave SA18N-30 or Equivalent Spectrum Analyzer Agilent N9030A To TMX B04 USB To Computer Shutdown Switch Ch 3 To TMX A01 3dB COAXIAL HYBRID Merrimac, QHM2M-6G or Midisco, MDC7226A Diode Detector Krytar 203A Power Sensor Agilent N1922A To Shutdown Switch, Ch 1 To TMX C06 USB To Computer 3dB COAXIAL HYBRID Merrimac, QHM2M-6G or Midisco, MDC7226A Diode Detector Krytar 203A Power Sensor Agilent N1922A Power Meter Agilent N1912A Forward Power To TMX C01 Reflected Power To TMX C02 3dB COAXIAL HYBRID Merrimac, QHM2M-6G or Midisco, MDC7226A Diode Detector Krytar 203A To TMX A04 Power Sensor Agilent N1922A Power Meter Agilent N1912A USB To Computer Forward Power To TMX C05 50dB Forward HP WR112 Load SMT Crossguide Coupler IFI DDCC-WR112-50F-30R 3dB COAXIAL HYBRID Merrimac, QHM2M-6G or Midisco, MDC7226A Power Sensor Agilent N1922A Power Meter Agilent N1912A Reflected Power To TMX C04 Forward Power To TMX C03 Diode Detector Krytar 203A 3dB COAXIAL HYBRID Merrimac, QHM2M-6G or Midisco, MDC7226A Power Sensor Agilent N1922A To TMX A02 USB To Computer 10dB Attenuator HP 8491A or Equivalent Diode Detector Krytar 203A To TMX A03 10dB Attenuator HP 8491A or Equivalent 6dB Attenuator HP 8491A or Equivalent 13

14 CIRCULATOR MULTIPACTION TESTING J3 J3 TC J1 J2 J2 TC J1 TC Cesium Sources BTM TC B/P TCs Images of the Unit in Thermal Vacuum Chamber, Including Current Probes, Temperature Sensors and Electron Sources 14

15 MULTIPACTION TEST RESULTS Multipaction Test on Standard Showing Event at 600 Watts peak 15

16 Circulator Multipaction Test Input/Output Power, Temperature & Pressure Profile 16

17 Circulator Multipaction Test Data-No Event J1 detector #1 J1 detector #2 RF On 1600 W PK J2 detector #1 J2 detector #2 J3 detector #1 J1 Probe J2 Probe J3 Probe Max Hold Reset on Spectrum Analyzer J1 3rd Harmonic J2 3rd Harmonic J1 Power Sensor 1 J1 Power Sensor 2 J2 Power Sensor 1 J2 Power Sensor 2 J3 Power Sensor 1 Multipaction Test at 7.0 GHz, -15 C, 1600 Watts peak 17

18 Circulator Multipaction Test Data-No Event Test at -15 C, Watts peak Test at -15 C, Watts peak Test at -15 C, Watts peak Test at -15 C, Watts peak 18

19 Circulator Multipaction Test Data-No Event Test at -15 C, 3000 Watts peak Dwell Test during temperature transition 3000 Watts peak Test at +25 C, 3000 Watts peak Dwell 19

20 Band Pass Filter Design Schematic of the Band Pass Filter SM41350 Internal ISO-View Filter assembly with housing, cover and connectors removed Lumped element filter in the MHz frequency band Pseudo-elliptic response with 10 poles and one transmission zero Uses air core inductors and ceramic single layer capacitors Coils made of pure silver with minimum unloaded Q of 125 at 85 C Ceramic capacitors or thick with much higher Q, typically >2000 Mounting base made of a controlled expansion alloy to reduce thermal stress on shunt capacitors Coils placed in individual cavities inside the housing to improve Q and avoid direct coupling between them Inductors soldered on Copper-Tungsten carriers which are soldered to shunt capacitors to achieve high Q and robust attachment 20

21 High Power and Multipaction-Free Design Table shows peak voltages at different nodes with 37.5 Watts peak power Voltages calculated at Fc = 200 MHz and at frequencies of maximum group delay, (141 MHz and 256 MHz). Maximum voltage build-up 128 Volts, occurring at node 4 at 141 MHz This voltage value is well below the break down voltage of all the material in the filter, but it s not known if it will not cause a multipactor breakdown Peak Voltage (Volts) Node Number, Refer to Schematic Frequency MHz MHz MHz

22 High Power and Multipaction-Free Design To protect the filter against Multipaction, it will be filled with low loss syntactic foam with high breakdown voltage (2.5KV/mm) Multipaction not possible with dielectrically impregnated RF cavities due to the free mean path of the electron being much smaller than the physical gap Theoretically, over the pass band frequency ( MHz), gaps smaller that will not multipact; however, all gaps will be filled with synthetic foam or with thin layers of Silicone RTV RTV filling in small confined regions will also minimize iso-thermal stresses. RTV is not ideal for bulk filling if cold processing temperatures are used due to the RTV mechanical properties as the temperature approaches Tg Due to the large organic load in the filter, substantial venting must be used to allow for outgassing and prevent a Corona discharge. The foam and RTV is considered an infinite source of gas 22

23 High Power and Multipaction-Free Design Filter with cover removed before adding foam Filter with cover removed foam filled 23

24 BPF Multipaction Testing Test Parameters Parameter Setting Notes Frequency 150 MHz and 250 MHz Power 80 W peak 4 W average Pulse Width Pressure Temperature 2ms, 5% duty factor <1.0e-5 Torr. -45 and +85 Deg. C Electron Source Cs 137 Source, 3 sources, 10 µc each Sample Rate 10 KHz and 10 Hz Detection Methods Return Loss Nulling Input/Output Third Harmonic Current Probes # of Samples Tested 10 Instant Change in any two parameter and/or anomaly in Pico ammeters 24

25 Test set-up calibrated prior to testing BPF MULTIPACTION TESTING Test Conditions Multipaction standard used to verify the set-up is capable to detect an event Power level ramped from 10 Watts to 80 Watts with 5 minutes dwell at each level. At the maximum level of 80 Watts peak, 4 Watts average, dwell time was 30 minutes Forward, reflected and output powers continuously monitored and recorded Return Loss Null and third harmonic continuously measured and recorded Pico ammeters placed at input and output through the vent holes to detect any possible anomaly Thermocouples placed on DUT and base plate continuously monitor and record the temperatures. Thermal vacuum chamber pressure continuously monitored Visual Inspection after multipaction testing using a microscope at 10x magnification and RF test according to the test plan 25

26 BPF MULTIPACTION TESTING 150 MHz Setup FORWARD/REVERSE POWER DUAL DIRECTIONAL COUPLER NARDA 3020A J1 INPUT RETURN LOSS NULL & 3RD HARMONIC DUAL DIRECTIONAL COUPLER NARDA 3020A J1 INPUT REFLECTION DETECTED DIRECTIONAL COUPLER NARDA USB TEST COMPUTER GPIB TO DATA ACQUISITION UNIT BP FILTER SM41350 ( MHz) POWER AMP IFI SMCC-500 SIGNAL GENERATOR AGILENT E8257C 20dB JFW 50-FH-C20-30 TRIGGER OUT TO SPECTRUM ANALYZERS, POWER METERS AND ASTROMED TMX B01 POWER SENSOR AGILENT N1922A RS-232 TO VACUUM/TEMPERATURE CONTROLLER -20 db FORWARD 20dB MACOM POWER METER AGILENT N1912A FORWARD TO ASTRO-MED TMX B04 Test Set-up Input -20 db REVERSE POWER SENSOR AGILENT N1922A REVERSE TO ASTRO-MED TMX B05 VARIABLE WEINSCHEL 905 (0-10 db) 10dB HP 8491A-010 STEP HP 355D (0-120 db) TERMINATION PASTERNACK PE db FORWARD IN USB TO TEST COMPUTER? DIRECTIONAL COUPLER NARDA 3020 VARIABLE WEINSCHEL (0-10 db) 10dB HP 8491A-010 PHASE SHIFTER ARRA 9425A (10 ) COAXIAL HYBRID NARDA 4029C -20 db IN S REVERSE FORWARD SPECTRUM ANALYZER #1 SPECTRUM ANALYZER AGILENT N9030A RETURN LOSS NULL TERMINATION PASTERNACK PE6009 HP FILTER PASTERNACK PE8718 (f c ~ 300 MHz) SPECTRUM ANALYZER #2 SPECTRUM ANALYZER AGILENT N9030A INPUT THIRD HARMONIC USB TO TEST COMPUTER 30dB MECA TERMINATION PASTERNACK PE6009 TO ASTRO-MED TMX A04 FROM E8257C TRIGGER OUT TO TRIGGER IN -20 db REVERSE DIODE DETECTOR KRYTAR 203BK TO DUT J1 IN TVAC CHAMBER 20dB MACOM TO ASTRO-MED TMX B02 TO SHUTDOWN SWITCH Ch 1 TO ASTRO-MED TMX A05 TO SHUTDOWN SWITCH Ch 3 FROM E8257C TRIGGER OUT TO TRIGGER IN 26

27 BPF MULTIPACTION TESTING J2 OUTPUT 3RD HARMONIC DUAL DIRECTIONAL COUPLER NARDA 3020A J2 OUTPUT POWER DIRECTIONAL COUPLER NARDA 3039B-20 FROM DUT J2 IN TVAC CHAMBER HP LOAD BIRD TERMALINE 8251N 20dB MACOM db FORWARD FILTER PASTERNACK PE db REVERSE TERMINATION PASTERNACK PE db FORWARD 20dB MACOM TERMINATION PASTERNACK PE6009 SPECTRUM ANALYZER #3 SPECTRUM ANALYZER AGILENT N9030A OUTPUT THIRD HARMONIC TO ASTRO-MED TMX A06 TO SHUTDOWN SWITCH Ch 4 FROM E8257C TRIGGER OUT TO TRIGGER IN POWER SENSOR AGILENT N1922A POWER METER AGILENT N1912A Test Set-up Output TO ASTRO-MED TMX B06 USB TEST COMPUTER 27

28 BPF MULTIPACTION TESTING TO SHUTDOWN SWITCH, Ch 6 DUT MOUNTING PLATE INCIDENT POWER: 75/85 WATTS PEAK 5% DUTY 2 ms PULSE WIDTH FROM TEST EQUIPMENT TO DUT J1 IN TVAC CHAMBER TO TMX A02 TO SHUTDOWN SWITCH, Ch 7 TO TMX A03 TO SHUTDOWN SWITCH, Ch 5 TO TMX A01 Picoammeter (See Figure 7) Picoammeter (See Figure 7) Picoammeter (See Figure 7) THERMAL VACUUM CHAMBER LACO VC-2000 DUT in Vacuum Chamber 10 µc SOURCE CS137 FROM DUT J2 IN TVAC CHAMBER TO TEST EQUIPMENT TO SHUTDOWN SWITCH, Ch 2 TO DATA ACQUISITION UNIT Ch 301 (DC Voltage) TO TMX B03 Chamber Pressure TNC MULTIPACTION TEST STANDARD VACUUM/TEMPERATURE CONTROLLER UNITRONICS V350-PLC Huber Unistat 705 CHAMBER CONTROLLER THERMOCOUPLE VACUUM CHAMBER HEAT EXCHANGER SHUTDOWN THERMOCOUPLE DUT AND BASEPLATE THERMOCOUPLES FLUID TEMPERATURE Ch 111 Ch 109 DATA ACQUISITION UNIT AGILENT ALARM TEMPCO TEC-90 D08 D06 D04 D03 CHART RECORDER ASTRO-MED TMX D05 VACUUM TELEMETRY TEMPERATURE TELEMETRY GPIB RS-232 TEST COMPUTER AGILENT VEE CONTROLLER 28

29 BPF MULTIPACTION TESTING Standard DUT Image of the DUT and Multipaction Standard in Thermal Vacuum Chamber 29

30 BPF MULTIPACTION TESTING Images of the Unit in Thermal Vacuum Chamber, including Thermocouples, Current Probes and Electron Sources 30

31 BPF Multipaction Test Data Power, Temperature and Pressure Profile 31

32 BPF Multipaction Test Data - Standard Multipaction Standard Test Showing an Event at 6.93 Watts peak 32

33 BPF Multipaction Test Data DUT, No Event Test at 150 MHz, -45 C Watts peak Test at 150 MHz, -45 C Watts peak 33

34 BPF Multipaction Test Data DUT, No Event Test at 150 MHz, Cold to Hot Transition 80 Watts peak Test at 150 MHz, Hot, 80 Watts peak Dwell 34

35 BPF Multipaction Test Data DUT, No Event Multipaction Test at 150 MHz, Hot, 80 Watts peak Dwell 35

36 High Power L-Band Iso-Combiner 36

37 High Power L-Band Iso-Combiner Input 200 Watts Termination Input 400 Watts Termination 400 Watts Termination Iso-Combiner Schematic Iso-Combiner Layout A high power L-band iso-combiner designed and tested for multipaction A 3-port device composed of a power combiner and two isolators, one at each input port Iso-combiner required to handle 450 Watts combined average power Iso-Combiner tested for Multipaction with combined input power up to 2028 Watts peak, Watts average with no evidence of multipaction 37

38 ISO-COMBINER MULTIPACTION ANALYSIS Combiner EM simulation with CST Microwave Studio to calculate Electric Field distribution of the combiner and obtain the peak voltages over critical gaps with 3170 Watts CW (200 Watts+12 db) power at each input port Voltage monitor #1 in the connector area with volts peak and a 2.48 mm gap Voltage monitor #2 in the combiner area with volts peak and a 3.24 mm gap. Voltage Monitor 1 Voltage Monitor 2 Voltage Monitors on the Combiner for EM Simulation 38

39 ISO-COMBINER MULTIPACTION ANALYSIS Gysel Combiner Worst Case Peak Voltage and Multipaction Safety Margin Voltage Monitor # Gap (mm) V M V P 20Log (V M /V p ) V P is the calculated voltage V M is Multipaction threshold (63 F gap for Silver) Multipaction Safety Margin= 20 Log(V M /V P ) Safety margins are negative numbers, indicating that an unprotected device would multipact with the specified power levels. 39

40 ISO-COMBINER MULTIPACTION ANALYSIS Isolator.128 [3.251] Circuit to housing floor.254 [6.448].130 [3.312].029 [.731] Circuit to Termination Carrier.275 [6.985] Minimum Gap.147 [3.740].108 [2.743] Ribbon to cover The minimum gap in the isolator is the distance between circuit trace and termination carrier, mm. At 1.55 GHz, fd = GHz mm and peak voltage threshold, V P for aluminum will be 33.7 V, using ESA/ESTEC calculator And maximum safe power is calculated from : P = V P 2 /Z = With Z = 50 ohms (the highest impedance in the isolator). This represents dB margin over the 3170 Watts CW requirement Without protection, the isolator would multipact with the specified power level 40

41 ISO-COMBINER MULTIPACTION ANALYSIS To increase multipaction threshold, the iso-combiner is filled with a low loss Syntactic foam with high breakdown voltage (2.5KV/mm) Foam will block any free path of secondary electron that may be released from the surface due to high RF power In addition, thin layers of silicone RTV is used to fill any gap between different parts of the device RF connectors are TNC Wedge type known for high breakdown threshold 41

42 ISO-COMBINER MULTIPACTION ANALYSIS Thermal Analysis Summary Different temperatures inside the device with 450 Watts combined average power and 0.35 db Specified Insertion Loss (The actual Insertion Loss was <0.3 db) Ambient Temperature Base plate Temperature Connector Temperature (TNC pin) Ferrite Temperature Foam Temperature 81 C C C C C These temperatures can affect the outgassing of the materials which may facilitate an eventual corona discharge with catastrophic results, and therefore needs to be verified by testing 42

43 ISO-COMBINER MULTIPACTION TESTING Test Parameters Parameter Setting Notes Frequency Combined Power Output Power (0.25dB component loss) Pulse Width Pressure Temperature 1575 MHz 2028 W peak W average 2ms, 40% duty factor <1.0e-5 Torr. -5, +25 and +85 Deg. C Electron Source Cs 137 Source, 3 sources, 10 µc each Detection Methods Dual Input Return Loss Nulling Input Third Harmonic Output Third Harmonic # of Samples Tested 2 Simultaneous increase in any two parameters 43

44 ISO-COMBINER MULTIPACTION TESTING Test Conditions Test-up calibrated before prior to Multipaction testing A Multipaction standard used to verify the test set-up Power level at each input port ramped from 50 Watts peak to 1014 Watts peak in 200 Watts intervals with 10 minutes dwell at each level. 60 minutes dwell at maximum power of 1014 Watts peak Forward, reflected and output powers continuously monitored and recorded Return loss nulls and third harmonic signals continuously monitored and recorded Several thermocouples placed on DUT and base plate to continuously monitor and record the temperature Thermal vacuum chamber pressure continuously monitored Visual Inspection after multipaction testing using a microscope at 10x magnification and RF test according to the test plan 44

45 20dB MULTIPACTION TEST SET-UP FORWARD/REVERSE POWER INPUT RETURN LOSS NULL 3 RD HARMONIC TRIGGER OUT TO SPECTRUM ANALYZERS DUAL DIRECTIONAL COUPLER NARDA 3022 DUAL DIRECTIONAL COUPLER NARDA 3022 TO DUT J1 IN TVAC CHAMBER SIGNAL GENERATOR AGILENT E8257C GPIB -20 db -20 db FORWARD REVERSE FORWARD -20 db -20 db REVERSE THIRD HARMONIC SIGNAL RF SHUTDOWN CIRCUIT 30dB MECA dB NARDA dB HP 8491A COUPLER NARDA 3024B-10 10dB HP 8491A SOLID STATE AMPLIFIER AMETEK IFI S2505-2KW-4KWP FILTER SM41347 SM80193 GYSEL DIVIDER POWER SENSOR POWER SENSOR AGILENT AGILENT N1922A N1922A POWER METER AGILENT N1912A TO USB ASTRO-MED TMX VARIABLE HP 394A 20dB MACOM IN S VARIABLE ARRA V PHASE SHIFTER NARDA 3752 IN COAXIAL HYBRID NARDA 3032 MACOM NULLING SIGNAL HP FILTER MINI CIRCUITS VHP-26 SPECTRUM ANALYZER #3 SPECTRUM ANALYZER AGILENT N9030A THIRD HARMONIC USB TO ASTRO-MED TMX FROM E8257C TRIGGER OUT TO TRIGGER IN TERMINATION USB SPECTRUM ANALYZER #1 SPECTRUM ANALYZER AGILENT N9030A RETURN LOSS NULL TO ASTRO-MED TMX FROM E8257C TRIGGER OUT TO TRIGGER IN DUAL DIRECTIONAL COUPLER NARDA 3022 DUAL DIRECTIONAL COUPLER NARDA 3022 GPIB TO DUT J2 IN TVAC CHAMBER TEST COMPUTER RS db -20 db FORWARD REVERSE FORWARD -20 db -20 db REVERSE THIRD HARMONIC SIGNAL USB 30dB MECA dB NARDA dB HP 8491A COUPLER NARDA 3024B-10 10dB HP 8491A POWER SENSOR AGILENT N1922A POWER SENSOR AGILENT N1922A VARIABLE HP 394A VARIABLE ARRA B HP FILTER MINI CIRCUITS VHP-26 USB POWER METER AGILENT N1912A TO ASTRO-MED TMX 20dB MACOM IN S PHASE SHIFTER NARDA 3752 IN COAXIAL HYBRID NARDA dB MACOM NULLING SIGNAL SPECTRUM ANALYZER #4 SPECTRUM ANALYZER AGILENT N9030A THIRD HARMONIC USB TO ASTRO-MED TMX FROM E8257C TRIGGER OUT TO TRIGGER IN Test Set-up Input TERMINATION USB SPECTRUM ANALYZER #2 SPECTRUM ANALYZER AGILENT N9030A RETURN LOSS NULL TO ASTRO-MED TMX FROM E8257C TRIGGER OUT TO TRIGGER IN 45

46 MULTIPACTION TEST SET-UP TNC MULTIPACTION TEST STANDARD THERMAL VACUUM CHAMBER LACO VC-2000 INCIDENT POWER: 1014 WATTS PEAK 40% DUTY CYCLE 2 ms PULSE WIDTH 5x 10 µc SOURCE CS137 (See Figure 3 for placemant) FROM TEST EQUIPMENT TO DUT J1 IN TVAC CHAMBER FROM DUT J3 IN TVAC CHAMBER TO TEST EQUIPMENT DUT MOUNTING PLATE VACUUM/TEMPERATURE CONTROLLER UNITRONICS V350-PLC Huber Unistat 705 J1 J3 J2 FROM TEST EQUIPMENT TO DUT J2 IN TVAC CHAMBER CONNECTOR THERMOCOUPLES THERMAL SHUTDOWN THERMOCOUPLE VACUUM CHAMBER HEAT EXCHANGER Alarm Tempco TEC-90 DUT AND BASEPLATE THERMOCOUPLES CONTROL/FLUID THERMOCOUPLE VACUUM TELEMETRY Data Acquisition Unit (MUX) Agilent TEMPERATURE TELEMETRY RF SHUTDOWN CIRCUIT GPIB RS-232 Chart Recorder Astro-Med TMX TEST COMPUTER DUT in Vacuum Chamber AGILENT VEE CONTROLLER 46

47 MULTIPACTION TEST SET-UP FORWARD/REVERSE POWER DUAL DIRECTIONAL COUPLER NARDA 3022 OUTPUT 3 RD HARMONIC COUPLER NARDA 3042B-20 FROM DUT J3 IN TVAC CHAMBER HP LOAD BIRD TERMALINE 8251N -20 db -20 db FORWARD REVERSE 10dB BIRD N 20dB JFW 50-FH-C20-30 Test Set-up Output POWER SENSOR AGILENT N1922A POWER METER AGILENT N1912A TERMINATION PASTERNICK PE6009 USB TEST COMPUTER HP FILTER MINI CIRCUITS VHP-26 SPECTRUM ANALYZER #5 SPECTRUM ANALYZER AGILENT N9030A THIRD HARMONIC TO ASTRO-MED TMX FROM E8257C TRIGGER OUT TO TRIGGER IN TO ASTRO-MED TMX 47

48 ISO-COMBINER MULTIPACTION TESTING Thermocouple W.L. Gore Wedge TNC Interface (PTFE Base Cable) Meggitt Safety Systems Wedge TNC Interface (SiO2 Base Cable) Cs137 Electron Seed Source Thermocouple Image of the Unit in Thermal Vacuum Chamber, Including Temperature Sensors and Electron Sources 48

49 ISO-COMBINER MULTIPACTION TESTING Vent Holes Image of the Unit in thermal Vacuum Chamber Showing Vent Holes 49

50 ISO-COMBINER MULTIPACTION TESTING Multipaction Standard Showing Event Return Loss Null Input, 5 Watts Return Loss Null Input, 70 Watts Multipaction Event Third Harmonic Input, 5 Watts Third Harmonic Input, 70 Watts Multipaction Event 50

51 ISO-COMBINER MULTIPACTION TESTING Multipaction Test on DUT Showing No Event Power Increase Combined Input Power Level Increased to 2028 W peak 51

52 ISO-COMBINER MULTIPACTION TESTING Multipaction Test on DUT Showing No Event Temperature Rise At Max. Power, Temperature Raised to 85 C 52

53 THANK YOU Sierra Microwave Technology 53