A Wide-Beam Circularly Polarized Asymmetric-Microstrip Antenna

Abstract

A wide-beam circularly polarized (CP) asymmetric microstrip antenna with four unequal circular-patches is proposed for global navigation satellite systems. Four unequal circular-patches are integrated symmetrically onto corners of a square microstrip radiator for CP radiation with wide-beamwidth. The measured 3-dB axial ratio (AR) bandwidth of the proposed antenna is 24.0 MHz (1.568-1.592 GHz) with a 3-dB AR beamwidth of around 180° across the bandwidth and a 10-dB return loss bandwidth is 56.0 MHz (1.556-1.612 GHz) with a gain of more than 5.0 dBic. The overall size of the antenna is 0.373λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">o</sub> ×0.373λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">o</sub> ×0.016λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">o</sub> at 1.6 GHz.