X-band Uav Sar Development Of The Traveling Wave Tube Transmitter,

Along with Travelling Wave Tube(TWT) invented in the early 1940's,This micor-wave power device already extended radar,electron-war,telemetry,communication industry ,TWT is a type of microwave device which transform electron beam kinetic energy into radio frequency electromagnetic wave.TWT has a lot of characters , such as broadband,high gain and efficiency,small size,light weight,control grid.Although vacuum device is replaced by solid state device in lots of fields, a great deal of uses which need high output RF power,high freqency , high efficiency and broadband is no other than vacuum device. With the advantage of high power,high efficiency and broadband, TWT which use to be the last stage amplifer device of transmitter has long life in the future development all the same.This paper introduces the design of a X band transmitter using TWT with peak output power 4kW,work pulse width 1μs-30μs,repetition frequencies 1kHz-2kHz variations.The article entirely introduces the TWT transmitter design of engineering-oriented principle including the project selection and caculation;the working principle of TWT; the design of the accessorial power supply of TWT;the transmitter system's control and monitor;the adaptability design of environment. This transmitter used in certain unmanned aerial vehicle SAR system .The subject mostly key technologies are listed as the followings:1,high voltage high power supply design and analyse based on series resonant topology;2,grid pulse modulation technology based on MOSFET;3,transmitter's control and monitor technology based on CPLD/FPGA;4,transmitter's adaptability design of environment .The subject mostly innovation1,developed a peak output power 4kW X band transmitter working on 12000m altitude successfully;2,solve the problem of high voltage insulate and heat dissipation on high altitude and low air pressure;3,improved the ability of design the aerial vehicle transmitter...