Microwave Amplifier Power SupplySlide 2Key Notes of TWTA:Application of TWTASlide 5Key Notes for Reading the Specification of TWTA:Who are in Business? (Power Supply Manufactures)Left: 600W Tri-band CW TWTA Right: Power SupplyMore ProductsHigh Voltage Filters Ready to be TestedTesting High-VoltageOur CustomersBlock Diagram of Switching PSMy Current Machine: 10kV 4-Collectors Test Set for L3Major ComponentsSlide 16Slide 17Slide 18Slide 19Slide 20Slide 21Slide 22Slide 23Slide 24Slide 25Slide 26Microwave Amplifier Power SupplyHigh Voltage Switching Power Supply Designat System Level Sharing Industry Experience with EE136Alex Chen MONDAY December 1, 2003Reference: http://www.twtas.com/pictures/factorywalk/faccathode.htmlBASICS of Traveling Wave Tube (TWT) AmplifierKey Notes of TWTA:•Heater/Filament is closest to Cathode Voltage.•Heater and Cathode act as electron gun, and they are on the side RF Input.•Collectors sits on RF output.•Electrons are fired from Cathode and received from Collectors.•RF signal is amplified through bunching effect after traveling along the path of Helix coil.*•Higher Cathode voltage  Higher RF Power *•Advantage of TWTA (over solid state amplification) is the linearity and output power*•TWTA Efficiency: 50% to 60% vs. Solid State: 25% to 30%•Ranges of Frequency for TWTA: 1Ghz – 40 Ghz•*Additional Information:– http://www.djmelectronics.com/articles/twt-vs-solid-state.htmlApplication of TWTA•Point to Point Communication•Satellite communication and Rader Appz•Missile tracking application for military•Television live broadcasting –LIVE news vans with satellite dishes on the roof carry TWTA insideSpecification of Communication TWT: MODEL NO. MEC 5417D From TELEDYNE ElectronicsTYPICAL OPERATING CONDITIONS POWER SUPPLY REQUIREMENTSELEMENT VOLTAGE CURRENTVOLTAGE MINVOLTAGE MAXCURRENT MAXHEATER -6 Vdc 1.6 A -5.8 Vdc -6.6 Vdc 2 AHELIXW/RFGROUND7 mAGROUND 10 mAW/O RF 1 mA GRID ON 200 Vdc 0.5 mA 100 Vdc 250 Vdc 10 mAGRID OFF -200 Vdc 0.1 mA -200 Vdc -500 Vdc 1 mACATHODE (Ek) -10.95 kV 290 mA -10 kV -11 kV 325 mA COLLECTOR W/ RF#1 6.1 kV 75 mA 56% x Ek + 2% 125 mA#2 4.4 kV 208 mA 40% x Ek + 2% 125 mAKey Notes for Reading the Specification of TWTA:•Cathode (Ek) Voltage is NEGATIVE.•Collector 1/2 reference to Cathode Voltage–Collector Voltages read POSITIVE•Heater Voltage also references Ek•Test Equipments (Ex: 1kX Divider) are reference to GroundGROUNDCollector 1Collector 2Cathode Heater Comparing Relative Voltages-6V+4kV+6kV-10kVWho are in Business? (Power Supply Manufactures)Left: 600W Tri-band CW TWTARight: Power SupplyProducts of ETM Electromatic Inc.www.etm-inc.com Interchangeable module-type Power SupplyMore Products•Astrium Project for Skynet: -15kV Cathode Voltage Power Supply (Far Left)-RF Amplifier by CPI (Right) with input RF source (front)Output dummy load (back)4-Astrium Units Combined for Project SkynetHigh Voltage Filters Ready to be TestedRight: High-Voltage Filters after assembly ready to be testedLeft: Potted filters to be retested (*Potting materials = High-Voltage Insulation)Testing High-VoltageHigh-Voltage modules are tested in flouriner (liquid insulator) before potted with liquid silicone rubberOur CustomersACinputPFCInputFilterorSecondaryBuckDriveC3DCtoACMOS4PrimaryMOS6Collector2Collector1CathodeGroundHeaterGRID PWMController~ -~ +~ -~ +~ -~ +~ +~ -Block Diagram of Switching PSDIODEHV FilterMy Current Machine: 10kV 4-Collectors Test Set for L3Major Components •Input Filter or PFC•H-Bridge: Buck + Full-Bridge•Pulse Width Modulation for H-Bridge•Diode•High-Voltage Filter•Heater •Grid Modulator•AC Fan Driver for cooling•Logic & Control•Human Interface Control•Low Voltage Power SupplyRED: Topics will not be discussed in class•Input Filter–LRC filtering with delay and soft-start–Phase Loss detection circuit•H-Bridge–Isolated Buck Converter to Full-Bridge–PWM controls Buck Converter.–Duty of Full-Bridge is fixed at 50%.–The use of transformers for gate driver circuits•PWM Board–Controls both buck drive and full-bridge.–Master/Slave Configuration for Buck to Full-Bridge–Gate Driver Chips–Pre/Post Regulation•Diode –Primary and Secondary Transformers–Voltage Doublers Circuit–High-Voltage diodes are used for rectification•High-Voltage Filter–RC Low Pass Filter–Feedback sense from Cathode Voltage to PWM•Post Regulation–Arc Detection Presentation Notes:•Fast Heater–Forward Regulator–Same chip as PWM chip–Two different voltage reference –Single-shot re-triggerable chip–Voltage Sense / Current Sense•400Hz Sinus Fan Driver–Boost, Half Bridge, Flyback –Hi/Low sides driver–Microcontroller with oscillator–Over voltage / Over Current DetectionPresentation Notes