Design of Broadband Slotted Ridge Waveguide Antenna for Lightweight SAR

With the increasing application range of miniature SAR satellites, the antenna needs to further reduce the weight and compress the volume while ensuring high resolution to meet the needs of the SAR system. The waveguide slot traveling wave array has broadband, and a single waveguide slot traveling wave array can be designed with more slots. In this paper, a light-weight spaceborne SAR waveguide slot array antenna operating in the X-band is designed. The antenna works in the quasi-traveling wave mode and consists of 6 single-ridge waveguide slot sub-arrays, each Broadband sub-array contains 24 radiation slots. The antenna sub-array efficiency is over 80%, and the mass density is 6.4Kg/m2. The maximum side lobe level and the zero-depth position measured on the azimuth plane all meet the indicators. On the premise of ensuring the bandwidth, the design achieves more slots in a single waveguide and reduces the weight of the antenna.