Design of a W-band one-dimensional beam scanning slotted waveguide antenna with narrow beam and low side lobe

In this paper, a W-band one-dimensional beam scanning slotted waveguide antenna with narrow beam and low side lobe is presented. The antenna is fabricated by cutting 76 inclined slots on the narrow wall of a standard WR-10 rectangular waveguide. Taylor synthesis method is used to suppress the side lobe level of the antenna. A great deal of tolerance analysis by using HFSS has been performed to avoid performance deterioration due to the errors of machining. The fabricated slot waveguide antenna has been tested by a Compact Range (CR) measurement system in an anechoic chamber. Measured gain of the slotted waveguide antenna is higher than 23.5 dBi for a frequency coverage of 75 GHz to 79 GHz, while the 3 dB beam width is 1.2 degree and the side lobe level lower than -20 dB in S-plane. The beam scanning range in S-plane is -6° to -1° when operation frequency sweeps from 75 to 79 GHz. The simulation and measured results indicate that the proposed slotted waveguide antenna is suitable for implementation of narrow beam, low side lobe, beam scanning antenna for high resolution imaging and detecting system based on W-band FMCW radar.