Design of a Dual-Circularly-Polarized Stacked Patch Antenna for SOTM application at Ka-band

A dual-circularly-polarized stacked patch antenna subarray block for satellite on the move (SOTM) applications at Ka-band is presented. The proposed multilayer antenna is designed for the downlink band operating in the region of 18 to 20 GHz with compliant scan performance up to ± 40° in both E- and H- planes. The subarray includes a highly integrated miniaturised 90° hybrid such that the antenna can operate in switchable circular polarisation. It also includes an integrated power splitting network based on Wilkinson. The antenna element size is 8.0 mm x 8.0 mm x 2 mm and achieves an impedance bandwidth and circular polarization bandwidth (3-dB axial ratio) of 2 GHz (18 – 20) GHz.