Notched Circular EBG based Circularly Polarized Antenna for Performance Enhancement

Abstract

In this article, a novel Compact Circularly Polarized Antenna with a notched circular Electromagnetic Band Gap (NCEBG) structure is put forward. This proposed structure comprises of a truncated rectangular patch antenna having its ground plane defected by slots etched on it to achieve compactness and wide impedance bandwidth. Electromagnetic Band Gap structures have the attractive feature of in-phase reflection and stopband creation for surface waves, enabling the surface waves to be suppressed; this, in turn, leads to enhanced performance of the antenna when loaded with such structures. For enhancing the functioning of the antenna with regard to its impedance bandwidth, axial ratio bandwidth and gain, seven NCEBG's are etched on the substrate which surrounds the truncated patch. Additionally, the antenna proposed in this research exhibits compactness with a low profile of 0.473 λo x 0.473 λo x 0.039 λo (λo at center frequency of 7.46GHz represents free space wavelength). The measured outcomes of the prototype-fabricated antenna match well with the results of the simulation, showing 3-dB axial ratio bandwidth of 13.66% and an impedance bandwidth of 73.29% having a peak gain of 7.32dBi in the operating band. The improved functioning of the proposed antenna marks it as a favorable applicant for wireless communication techniques and thus finding its application in various ways.

Index Terms
Circularly polarized; Defected Ground Structure; Gain; Impedance Bandwidth; Notched Circular Electromagnetic Band Gap