A Low-Profile High-Gain Circularly Polarized Antenna Using Quarter-Mode Substrate Integrated Waveguide Technique

A high gain circularly polarized antenna with a single-layer is proposed in this paper. The antenna consists of a chamfered microstrip patch at the center and four identical quarter-mode substrate integrated waveguide (QMSIW) cavities connected to the corners of the microstrip patch. The electric fields distribution of the central microstrip patch under radiation of TM
120
and TM
210
modes are studied in this paper to design the proposed antenna. The gain of the proposed antenna is enhanced due to the equivalent magnetic currents around the radiating edges are in the same direction. The simulated peak gain of the proposed left-hand circularly polarized (LHCP) antenna has achieved 13.1 dBi at 7.79GHz, the 3dB axial ratio bandwidth and −10dB impedance bandwidth are 7.78GHz-7.80GHz and 7.73GHz-7.83GHz, respectively.