Investigation of dual-polarised printed slot antenna for folded reflectarray unit cells at Ka band

A novel dual-polarised slot type printed antenna with superior high beam scanning performance in a unit cell boundary condition for the folded reflectarray is presented and characterised. This antenna is intended for operation at Ka-band and designed using multi-layer printed circuit board (PCB) technology. The proposed design incorporates shorting vias around the slot as well as a dielectric grid on the top of the antenna in order to achieve improved performance at the higher scanning angles for both polarisations. The effectiveness of beam scanning of the proposed unit cell design, especially at higher scanning angle at 60°, is evaluated with incident waves at various angles in the periodical boundary. The simulation results have shown the proposed unit cell antenna has the capability of beam scanning with good performance up to 60° for both E-plane and H-plane at the designated operational band, indicating that a folded reflectarray with excellent beam scanning performance, designed on the basis of this novel unit cell antenna element, can be realized.