A Single Feed Circularly Polarized Planar Antenna Array

A design of a circularly polarized planar antenna array of elliptical patches is presented. The designed prototype has been verified experimentally. Elliptical patches produce circular polarization by using a single feed only. A corporate feed network with quarter-wave transformers are used for uniform excitation of all the array elements. Primary advantages of the presented antenna array are structural simplicity, good circular polarization characteristics and no side lobes. Here, the design example is given for 2×2 elliptical patches at 2.8 GHz. Similar procedure can be extended for more number of array elements at the desired frequency of operation to cater the need of communication systems where circular polarization is essential.