High-Gain Circularly Polarised Beam Scanning in Slotted Waveguide Antennas

This manuscript presents a slotted waveguide antenna array design that operates at the D band (140-180 GHz) of the Terahertz regime. The proposed geometry provides a wide bandwidth (140-175 GHz), owing 22.5% fractional bandwidth and a high gain up to 14 dBi. The design enables beam scanning property, scanning over a range from 8° - 45°. A single Z slot shifts the polarisation of the driving element from linear polarisation to circular polarisation, providing an axial ratio bandwidth of 35 GHz.