The New C-Shaped Parasitic Strip for the Single-Feed Circularly Polarized (CP) Microstrip Antenna Design

A new single-feed circularly polarized (CP) microstrip antenna with the C-shaped parasitic strip is proposed in this paper. The proposed CP antenna is designed for the transmitting terminal in the Global Navigation Satellite System (GNSS). The square patch is surrounded by a C-shaped parasitic strip. By adjusting the parasitic strip dimension, the antenna CP operation is achieved. The main advantage of this method is that those two resonant modes for achieving the CP operation are independent from each other, which is liable to design and debug the proposed CP microstrip antenna. The designed CP microstrip antenna has the good impedance matching, the good CP radiation pattern, and the stable CP gain across the 3 dB AR (axial ratio) bandwidth.