A DESIGN OF MINIATURIZED ULTRA-WIDEBAND PRINTED SLOT ANTENNA WITH 3.5/5.5 GHz DUAL BAND-NOTCHED CHARACTERISTICS: ANALYSIS AND IMPLEMENTATION

A design and analysis of a novel proximity-fed printed slot antenna with 3.5/5.5 GHz dual band-notched characteristics are presented. To obtain an ultra-wideband (UWB) response, a circular patch with a rectangular conjunction arm is etched concentrically inside a ground plane aperture. The antenna is proximity-fed by a microstrip line with an open shunt stub on the other side of the substrate. The designed antenna satisfies a −10 dB return loss requirement in the frequency band from 2.7 to 17 GHz. In order to obtain dual band-notched properties at 3.5 and 5.5 GHz, an open ring slot is etched off the circular patch and a π-shaped slot is etched off the microstrip feeding line, respectively. A curve fitting formulation is obtained to describe the influences of the notched resonators on the corresponding notched frequencies. The proposed antenna is designed, simulated and fabricated. The measured data show a good agreement with the simulated results and the equivalent circuit results through the use of a modified Vector Fitting technique for a rational function approximation. The proposed antenna provides almost omnidirectional radiation patterns, relatively flat gain and high radiation efficiency over the entire UWB frequency excluding the two rejected bands. Received 13 April 2013, Accepted 10 May 2013, Scheduled 21 May 2013 * Corresponding author: Mohamed Mamdouh M. Ali ([email protected]). 38 Ali, Saad, and Khaled