A Two-Chip Cascaded FMCW Radar For 2D Angle Estimation

Recently, radar sensors with four-dimensional (4D) high resolution are demanded for point cloud processing in automotive radar field. To achieve this goal, a large amount of transmit (TX) and receive (RX) channels are required for radar systems. Commonly, a monolithic microwave integrated circuits (MMIC) chip of an automotive radar has only 3 TX and 4 RX channels. The resolution is restricted by the limited number of transceiver (TRX) channels. Hence, in this paper, a compact and affordable two-chip cascaded frequency modulated continuous wave (FMCW) radar system is presented. Based on the multiple-input multiple-output (MIMO) technology and sparse array method, the proposed module can provide an angular resolution of 3.8° in azimuth and 16° in elevation. In order to demonstrate the designed system performance, further measurement is implemented in microwave anechoic chamber. The measured results show good accordance to the simulations.

I. Introduction

Thanks to the robust performance against extreme weather and light changing, radar sensors become compelling means to detect other vehicles or vulnerable road users under full conditions [1]. Nowadays, thousands of advanced radar systems are updated every year, which are based on the mature silicon technology. The continuous maturity of highly integrated monolithic microwave integrated circuits (MMICs) [2]–[3], planar antennas and radio frequency (RF) signal processing methods, in turn, promotes the generation of more powerful and sophisticated radar systems. The increasing performance of radar sensors ensure not only the detection of single reflection of remote target but also the whole environment representation by a two-dimensional (2D) scheme. Currently, the rapid development of four-dimensional (4D) radar also requires angle estimation ability among elevational direction [4].