A circularly polarized patch antenna with a slotted parasitic loop

Abstract

In the letter, a circularly polarized (CP) patch antenna is proposed, which consists of a slotted radiation patch, a slotted parasitic loop with a short pin, and a ground plane. The slot with one open and one circular end is etched in the radiation patch, and the current distribution of the radiation patch is disturbed to excite the first CP mode. The currents distributed on the slotted radiation patch and parasitic loop can superimpose or cancel each other to produce the second CP mode. Impedance matching and the performance of