Pin-loaded circularly-polarized patch antenna with enhanced gain

The directivity and gain of a circularly-polarized patch antenna are enhanced by introducing two sets of shorting pins in this paper. The resonant frequency of the antenna is at first studied to demonstrate its increment by making use of the shunt-inductive effect of shorting pins. As a result, its electrical size of a square patch radiator is effectively enlarged so as to enhance its radiation directivity. Next, the two degenerate modes of this resonating patch antenna are properly separated for circularly-polarized radiation by varying the spacing of a pair of shorting pins. In final, the simulated and measured results demonstrate that the directivity of the proposed antenna can be enhanced to 10.8 dBic, with about 2.8 dB increment.