Dual-band circularly polarized monopole antenna

Abstract

This paper proposes a dual-band circular polarization (CP) monopole antenna. This antenna can generate a broadband impedance-bandwidth from 2.17 to 8.47 GHz, and excite a left-hand circular polarization (LHCP) at 2.48 GHz and right-hand circular polarization (RHCP) at 3.90 GHz. The measured 3-dB axial ratio (AR) bandwidths are about 140 MHz from 2.41 to 2.55 GHz approximately 5.6% with respect to the center frequency at 2.48 GHz and 900 MHz from 3.45 to 4.35 GHz approximately 23.1% with respect to the center frequency at 3.90 GHz.