Design of a reflectarray antenna at 300 GHz based on cells with three coplanar dipoles

Simulated results are presented for a reflectarray antenna designed to produce a collimated beam at 300 GHz within a 13% bandwidth. The reflectarray cells are made of three parallel dipoles printed on one side of a 110-μm Quartz wafer coated with a conductive ground plane on the back side, where the phase is adjusted by varying the length of the dipoles. A practically linear phase variation is achieved in a range greater than 360° and frequencies from 280 GHz to 320 GHz. A reflectarray antenna was designed taking into account the angle of incidence and the polarization of the incident field. The simulated radiation patterns show a fixed collimated beam with variations in gain lower than 2.6 dB within a 13% bandwidth.