A compact and broadband printed monopole antenna for circular polarization

Abstract

In this paper, a compact and broadband printed monopole antenna for circular polarization is proposed. The miniaturization is achieved by inserting a triangle notch to the rectangular patch. Moreover, the broadband circular polarization is achieved by designing the antenna asymmetrically to the microstrip line. The simulated and measured bandwidth of the 10 dB-return loss with a 3 dB-axial ratio is 33.3% (2.50 GHz–3.50 GHz) and 37.8% (2.55 GHz–3.74 GHz). The size of the antenna is 0.147λ_c² (λ_c is a wavelength in free space at the center frequency).