A 2 × 2 Ka-Band Wideband Circularly Polarized Sub-Array Antenna Based on U-shaped Slots and Gap Waveguide Technology

Paper in proceeding, 2023

This paper introduces a novel 2 × 2 U-shaped sub-array antenna with circular polarization, specifically designed for Ka-band satellite communication terminals. The sub-array is composed of a gap waveguide feed layer, a cavity layer and a radiating layer. U-shaped radiating slots are placed on the top plate. In the second layer, a coupling slot and circular polarization-generating ridges are placed in a gap waveguide cavity and the cavity layer is fed by a ridge gap waveguide feeding. The simulation of the proposed array antenna exhibits good performance, including a low axial ratio (below 3 dB) over a bandwidth of 28-34.6 GHz, high gain (12.3 dBi at the center frequency of 31.5 GHz) in the broadside direction, low relative sidelobe level (SLL), and also low-profile and planar design. All these characteristics make the proposed antenna a very promising solution for next-generation satellite communication systems.