An Ultra-Wideband Modified Aperture-Coupled Millimeter-Wave Reflectarray Antenna

A modified aperture-coupled patch antenna element is presented in this paper to improve the operating frequency bandwidth of a Ka-band reflectarray. The proposed antenna consists of four metallic layers and three dielectric substrates. Ultra-wideband frequency bandwidth can be achieved when both the patch and the slot are excited for radiation. Simulation results show that the proposed reflectarray unit-cell operates over the frequency band (29-40 GHz) similar to 32% with a low reflection loss less than 0.5 dB for both normal and 45 degrees incident angles.