Research On Key Circuits Of 220GHz Multichannel Radar Front-end

Gesture recognition is a more natural and convenient way of human-computer interaction,which has broad application prospects in the future of "Internet of Everything and Intelligence of Everything".Terahertz radar is flexible,convenient,highly recognizable and can capture subtle gesture information,which meets the application requirements of gesture recognition.Therefore,this thesis studies the front-end of220 GHz one-transmitter and three-receiver radar based on FMCW system,and designs,processes and tests some key devices needed by it.Starting from the radar front-end system architecture,the driving signals are transmitted by frequency multipling and received by direct down-conversion through power dividers,and the 220 GHz third harmonic mixer and 220 GHz tripler are driven through one link,thus ensuring the coherence of signals and realizing the miniaturization of radar structure.Based on this system scheme,a 220 GHz passive balanced tripler,an E-band four-way power divider,two E-band amplifiers and various E-band switching components are developed in this thesis.The experimental results show that the efficiency of the tripler is higher than 1.7% in the range of 212.4-229.2 GHz;in the range of 64-80 GHz,the insertion loss of E-band four-way power divider is lower than 6.9 d B,the amplitude unbalance is lower than 0.7 d B,and the isolation is lower than-20 d B;the output power of the two E-band amplifiers is higher than 16 d Bm and 20 d Bm respectively in the range of 66-79 GHz.Combined with other radar sub-modules such as 220 GHz third harmonic mixer,220 GHz antenna and 220 GHz low noise amplifier provided by the three parties,a complete 220 GHz radar front-end system is built.The radar system is divided into transceiver and transceiver,which are tested respectively to verify the radar performance.Experiments show that the transmission power of the radar transmission link is higher than 3m W in the range of 211.8-229.1 GHz;In the range of 210-230 GHz,the receiving link gain is higher than 3d B,and the receiving noise temperature is lower than 1000 K,which meets the short-range test requirements of gesture recognition radar front-end.To sum up,this thesis provides a feasible scheme for the front-end design of terahertz multi-channel radar based on gesture recognition technology.