Design for High Gain of Slotted Waveguide Array RADAR Antenna Combined with Grid Cavity

A design for high gain realization of a slotted waveguide array antenna combined with a grid cavity for a sea wave monitoring RADAR system was proposed in this paper. The grid cavity on the radiating antenna plays in role to suppress the sidelobe level and to increase the antenna gain. A bandwidth of 2.8% or more based on the - 10 dB reflection coefficients was observed by measurement. Due to the grid cavity, the first sidelobe level was improved by approximately 2 dB. Proposed antenna gain was observed at approximately 30.5 dBi in measurement, which improved 1 dBi compared with the without grid cavity slotted waveguide array antenna.