Millimeter-wave Variable Pulse Width Pulsed Solid-state Oscillator Technology

A key element in many millimeter-wave systems is the solid-state pulsed sources.These sources,because of their small size,light weight,low voltage power supply requirement and long use life, are widely applied to tracking radar,missile seeking,and communication systems. The distance performance of radar mostly lie on the power of the transmitter,not peak but average.So with the same repetition frequency,the wider the pulse-width is,it is the higher average power to the transmitter,and the larger the operation distance of radar is.But the resolving power of radar is in inverse proportion to the pulse-width. The pulse is the narrower in width , then the wider frequency spectrum is, it is the more accurate to find range. So we have launched the research of variable pulse-width pulse solid state oscillator technology. This paper first describes the theory of pulsed modulator,which is the key item in the development of highly stable,high power pulsed oscillators,especially in millimeter-wave radar systems of pulsed mode.Then we have made two kinds of different circuit structure pulsed modulators,corresponding the different require of Gunn oscillator and IMPATT oscillator. The pulsed modulators made by us have been successfully used for multistage injection locked oscillator-chain at 94GHz.A two-stage injection locked 94GHz IMPATT oscillator-chain is used to amplify an input power of roughly 12mW at 47GHz to an output power of 100mW peak.The oscillator-chain is operated at a pulse repetition frequency of 50kHz and output adjustable pulse-width of 200ns or 2us.