Rectangular Grating Waveguide Slot Array Antenna for SATCOM Applications

This paper introduces a rectangular grating waveguide slot array antenna that provides a method for the design of satellite communication (SATCOM) receiving antennas. By integrating the radiating slots with a rectangular grating waveguide, which functions as a frequency-selective transmission line, the antenna realizes an extra filtering response. The operation bandwidth and out-of-band rejection of the antenna can be tuned by adjusting the rectangular grating waveguide parameters. In order to verify the proposed design concept, a prototype $Ku$ -band eight-slot rectangular grating waveguide slot array antenna is designed, fabricated, and measured, and its performance is compared with that of the conventional eight-slot rectangular waveguide slot array antenna. The results show that the proposed antenna works well in the receiving frequencies of 12.25-12.75 GHz and suppresses the realized gains with additional measured 14.8-21.3 dB in the transmitting frequencies of 14.0-14.5 GHz, which confirms its extra filtering response. Simultaneously, the measured antenna efficiency of the proposed antenna (68.3%-88.8%) is similar to that of the conventional antenna (66.9%-84.6%).