A High-Performance SIW Slot Antenna Array for mmWave Radar

In this paper, a high-performance millimeter-wave radar antenna is designed. This antenna is Substrate Integrated Waveguide (SIW) planar slotted array with narrow beam width, high gain and low sidelobe level at 77 GHz. Firstly, the excitation amplitude distribution of the array element corresponding to −20 dB sidelobe level is obtained by Taylor synthesis method. Thus, the design parameters of the array elements can be obtained. The feed network of the antenna is composed of an air-filled rectangular waveguide (RWG) to Substrate Integrated Waveguide (SIW) transition and a power division feed network. Finally, the array element and the feed network are combined to form an $8\times 16$ slot array. The overall simulation design is carried out in HFSS. In the simulation, RWG is used to replace SIW equivalently to accelerate the simulation speed and save design resources. The simulation results show that the gain at 77 GHz is 21.4 dB with 75 % radiation efficiency, and the front-to-back ratio is 45.5 dB. Within the relative bandwidth of 2 %, the VSWR of the feed port is less than 1.78. The design can satisfy the antenna requirements in millimeter-wave radar systems.