A compact multiband circularly polarized antenna exploiting meander geometry

Abstract

A compact triple-band circularly polarized (CP) planar monopole antenna is presented for wireless communication. The proposed antenna design consists of a meander geometry and two orthogonal stubs in the top layer, whereas a vertical slot is etched in the partial ground plane. The geometry exhibits 10-dB impedance bandwidth of 450 MHz (3.83-4.28 GHz), 560 MHz (5.41-5.97 GHz), and 830 MHz (6.47-7.3 GHz) at three different resonant frequencies. The 3-dB axial ratio (AR) bandwidth obtained around these resonances are 4.29%, 4.03%, and 3.52% with respect to 4.1 GHz, 5.8 GHz, and 6.7 GHz, respectively. In addition, the proposed antenna exhibits an improved miniaturized performance having an overall size of 0.35λ × 0.39λ, where λ is the free space wavelength at the lowest CP frequency. Moreover, the antenna has a simple topology, broadside radiation, and moderate gain. The proposed structure has been fabricated and its measured responses are in good agreement with the simulated results. © 2021 IEICE.