Wide Beam Antenna for MIMO-Based Automotive Radar Applications

Abstract

In this article, a new microstrip antenna design is proposed that offers a wide half-power beamwidth over a frequency range of 77-81 GHz. The antenna has a size of 7x7x0.508µm³ and is built on a Taconic substrate (εr=2.2). Parasitics are used in the antenna to enhance the beamwidths to 158.6°,149.6°, and 139°, at 77 GHz, 79 GHz, and 81 GHz, respectively. A 2x2 MIMO arrangement is also studied to increase the overall gain of the system up to 12.2 dB, although there is a slight reduction in the beamwidths to 139.9°, 142.7°, and 133.5° at 77 GHz, 79 GHz, and 81 GHz respectively. The single element as well as the MIMO configuration achieve side lobe level suppression of -10.9 dB. The analysis of different MIMO performance metrics, including envelope correlation coefficient, channel capacity loss, diversity gain, mean effective gain, TARC, etc., has shown that they are all within acceptable ranges.