A Triple-Frequency Circularly Polarized Microstrip Patch Antenna

Abstract

In this paper, a circularly polarized microstrip patch antenna is proposed for triple-frequency operation. To achieve triple-frequency operation, the proposed antenna has three layers. The proposed antenna is designed and experimentally analyzed at three different frequencies. From the measured results, the resonator frequencies of this antenna are 1.207GHz, 1.268GHz and 1.561GHz, and the measured impedance bandwidths are 22MHz, 10MHz, and 40MHz for VSWR<2. The measured gains are 4.15dBi, 3.75dBi, and 3.05dBi, respectively, and the lowest gain at low-angle (at an elevation of 10 degrees) is -0.5dBi. The measured results and analyses are presented