A compact and broadband printed monopole antenna for circular polarization

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 0.147 lambda(2)(c)(lambda(c) is a wavelength in free space at the center frequency).