Research And Design Of X-band FMCW Radar Antenna And RF Receive

Antenna and RF receiver are important components of FMCW radar,so the research and design of antenna and RF receiver is the key to ensure the high performance of FMCW radar.This paper first introduces the important electrical parameters of transceiver antenna and RF receiver and several common receivers.Then the design of the antenna part is described in detail.Firstly,the design process of the microstrip patch antenna element and the transceiver antenna sub-array is introduced.The sub-array design adopts the form of 4-element microstrip series feed array fed by the center,and reduces the sidelobe level of the antenna by Chebyshev synthesis method.Then,an antenna array arrangement method used for 2-D interferometer direction finding is introduced.The accuracy of 2-D array arrangement method is less than 0.9°,and the range of direction finding without ambiguity can be covered(-70°,+70°).The direction finding error of this array arrangement method is analyzed.Because the isolation degree of transmitting and receiving antenna seriously affects the system performance of FMCW radar,the isolation degree is optimized after the design and processing of transmitting and receiving antenna array.The isolation degree is increased from 52 dB to 79 dB by optimizing the array layout,loading metal baffle and laying absorbing material.In the design of RF receiver,first through the analysis of radar system index requirements,the index requirements of the receiver are determined,and then through the analysis and comparison of several receivers,finally the form of zero IF receiver is determined.In the process of scheme design and chip selection,the low noise factor of the receiver is taken into account while ensuring that the receiver’s various indicators can meet the requirements.The subsequent simulation shows that the noise coefficient of the designed receiver is only 1.817 dB.After measurement,the noise coefficient of the six receiving channels is about 2.6dB.This topic also completed the design of the PCB layout of the receiver and the design of the shielding cavity,and also tested the key indicators of the real object processed.