8 Rx, 1 Rx 79 GHz Sparse Array FMCW Radar System

This paper describes a 79 GHz frequency modulated continuous wave (FMCW) radar system with a sparse array to achieve high angular resolution with fewer Rx channels. The system consisted of one Tx channel and eight Rx channels placed in a nonlinear sparse array. The 79 GHz Tx and Rx chips were designed using a 65 nm CMOS process, and the measured transmission power was 10.93 dBm, conversion gain of the Rx was 30.1 dB, and noise figure is ~13 dB at a 1 MHz IF signal. The Rx antenna array consisted of a 1×8 array of azimuth directions and a microstrip patch antenna with a simulation gain of ~16.5 dBi was designed for the Tx and Rx antennas. The chirp time of the system is 100 μs, and the data was given a gain of 20 dB on the baseband board with filtering and sampled at a rate of 5 MSPS with an eight-channel 12-bit ADC. The corresponding ADC data were acquired by the FPGA, and the target distance and angle information were obtained based on the FFT. Subsequently, the distance and angle estimation of the target and angle resolution of the system were verified through measurements.