A single feed microstrip patch elliptically annular antenna array has been proposed for high gain circularly polarized (CP) radiation. An array of elliptically annular patches antenna resonates at a frequency of 3.77 GHz which can be used in satellite communication and radar application. A corporate feed network with quarter-wave transformer has been used for uniform excitation of all the array elements. Thus a good circular polarization is obtained by using a single feed with enhanced gain 15.62 dB compared to single patch. The radiation pattern, axial ratio and input impedance of the proposed elliptically annular antenna array is compared with single element elliptically annular antenna. A substantial gain enhancement with low side lobe level (SLL) is observed keeping circular polarization intact. Further, simulated and measured results of the proposed antenna array have been compared and found that axial ratio and gain are in good agreement.
Broadband circularly polarized high-gain antenna design based on linear-to-circular polarization conversion focusing metasurface
