Low-Profile Circularly Polarized Antenna with Wide AR Beam-width for WIFI Application

A low-profile circularly polarized (CP) antenna with wide axial ratio beam-width (ARBW) for WIFI application is proposed. A circular slot is etched on the patch and multimetallic vias are loaded around the corner of patch, which not only achieves antenna miniaturization, but also results in a high purity E-field distribution. Due to that the ground folds to the surface of substrate by loading metallic vias, pure horizontally polarized E-field is produced around the slot and a wide ARBW is obtained. Two degenerate modes in a single-fed patch antenna is slightly separated by the metallic vias, so a CP radiation is achieved. The proposed CP antenna exhibits a low-profile of 0.015 `λ. Its measured -10 dB bandwidth, AR bandwidth, ARBW, peak gain and efficiency are 2.36-2.49 GHz (5.4 %), 2.37-2.41 GHz (1.7 %), 155°, 5.2 dBic and -0.28 dB (93.7 %), respectively. It features a low-profile, simple design, wide ARBW and high radiation performance, which is very suitable for IOT systems.