Broad band parasitically coupled concentric semi circular elliptically ring antenna surrounding an elliptical patch with air gap

The paper presents the performance of a parasitically coupled semi circular elliptical ring antenna surrounding elliptical patch geometry having air gap between conducting patch and ground plane. With proposed modifications in the conventional circular patch geometry, the bandwidth of modified antenna with an air gap is around seven times higher than that of a simple circular patch antenna. The gain, directivity and efficiency of modified circular patch antenna with air gap is also improved to some extent but still these are less than desired values. The E and H plane radiation patterns presented by antenna in the frequency range where broadband performance is obtained are identical in shape and nature. Direction of maximum intensity retained by antenna at both frequencies is normal to patch geometry.