A Low Sidelobe Waveguide Slot Antenna with Loading Patches Array

In this paper, we propose a low sidelobe waveguide slot antenna with loading patches array. We use SIW structure at the bottom of the antenna to form a rectangular waveguide cavity, etch eight equally sized gaps above it, and load patches array at the top of antenna. Eight different sized patches are used to achieve a low sidelobe design. The simulation results indicate that the antenna maintains a low sidelobe level, below -19.6 dB, across the frequency range from 76 GHz to 77.25 GHz, and boasts a broad operational bandwidth extending from 76 GHz to 80.5 GHz. a high gain of 13.85 dBi and a high radiation efficiency of 96.3% at 77 GHz.