Double circular ring compact antenna for ultra-wideband applications

Abstract

A simple, low-cost and compact antenna is presented for ultra-wideband applications. The proposed antenna design has improved characteristics as compared to the available different designs reported in the recent literature. The antenna is designed on FR4 substrate with microstrip feed line. Better results are obtained by optimising the geometrical parameters of patch and the lengths of ground and strip line. According to the criteria of -10 dB matching bandwidth, the designed antenna covers a high bandwidth ranging from 3.1 to 16 GHz. It was identified that the voltage to standing wave ratio is less than 2 which is also the desired characteristic for matching of an efficient antenna. The maximum dimension of this antenna is smaller than 0.27λ0 at the lowest frequency of operation, where λ0 is the free space wavelength. Further, low-cost, smaller size and simple design of the proposed antenna makes it very suitable for biomedical applications.