Bandwidth Enhancement of a Compact Slot Antenna with Frequency Scale Up/down Capability

Abstract

In this paper, a printed wideband slot antenna is proposed and investigated. The antenna geometry consists of a 45° rotated square slot and a circular parasitic patch situated at its center. In addition, the slot consists of four rectangular notches at every corner. It brings close the resonances of both slot and circular patches and enhances bandwidth. The antenna achieved the measured impedance bandwidth of 111.7% from 2.24 to 7.91 GHz, with almost stable pattern. Furthermore, a comprehensive parametric study has been carried out to prepare a set of guidelines to scale up or down the antenna for a specified impedance bandwidth (111.7%) between different frequency ranges. The frequency scaling feature has been verified by simulating a set of antennas for different frequency bands. The result demonstrates that all antennas under test yield almost equal impedance bandwidth.