A Square Patch Partially Reflective Surface for Improving the Antenna Gain Characteristic of Low-Cost Dual Polarized Microstrip Antenna

Abstract

This paper presents an improvement gain of a dual-polarized microstrip patch antenna by using the partially reflective surface (PRS). The PRS is designed from a $10 \times 10$ array patches structure, which is patterned on a 0.8-mm FR-4 substrate. A-dual-port fed by two SMA connectors, which is selected to use as the source of an experiment. The square metallic patch is used to design the PRS layer. The dimension of the square patch is 5 mm $\times 5$ mm. The length of the square patch is varied from 3.0mm to 4.5 mm by step of 0.5 mm to investigate the reflection coefficients, e.g., magnitude response and phase response. Based on the simulated results, a 4.5-mm square patch provides the highest reflection coefficient of 0.53. To prove the design concept, the size of a square patch of 4.5 mm is selected to fabricate and measure the radiation pattern. At an operating frequency of 3.5 GHz, the maximum gain at the zero degrees is increased from 1.2 dBi to 4.96 dBi when compared without and with PRS.