Subarray Antenna Design for Inter-Satellite Communication Link at 60 GHz with Digital Beamforming

A 2×16 subarray antenna design is proposed, tailored for beamforming and electronic beam steering applications at 60 GHz for inter-satellite communication. The subarray design combines the phase shift architecture and the offset topology to achieve a wide 3 dB axial ratio bandwidth for circular polarization and low grating lobes below -20 dB. The proposed subarray operates from 59 - 61 GHz providing wide impedance bandwidth (>2 GHz) with broad right-hand circular polarisation bandwidth. The 2×16 subarray is further evaluated to predict the antenna performance of 64×64 array which consists of 128 subarrays. The proposed array of 64×64 radiating elements has an overall size of 195 mm × 154 mm × 0.676 mm. It provides a relatively high gain of 36 dBi and a low grating lobe with peak values less than -25 dBi when steering the beam with an angle of ±7.6°.