Circular Polarization Switchable Planar Array Antenna Based on Gap Waveguide Technology

A dual-band circular polarization switchable planar array based on gap waveguide (GW) technology is presented. The array consists of a dual-circularly polarized (DCP) waveguide radiator that utilizes a septum polarizer, a metal plate with pins, and a 1 to 4 power divider. The polarization of the array can be switched between right-hand circular polarization (RHCP) and left-hand circular polarization (LHCP) by moving the radiator position relative to the other two parts. The simulated results show that the proposed array antenna works in dual bands of 19-21.2 GHz and 27.5-30 GHz, with return loss better than 12 dB, an axial ratio below 3 dB, and an antenna efficiency higher than 68%.