Design and modal analysis of dual-slot circular patch antenna for ultra-wideband applications

A novel and high performance UWB antenna is designed in the present work. The proposed antenna consists of a slotted circular disk with Defected Ground Structure (DGS). The rectangular and bevel-shaped slots are inserted in the circular radiating patch and on the top edge of the partial ground plane, respectively, to change the mode behavior and exhibit multiple resonance modes. Characteristic Mode Analysis (CMA) is the latest emerging technique in understanding the radiation phenomena of the antenna. The developed antenna is analysed by using CMA and various modal parameters like characteristic angle, modal significance and modal patterns are used to study the performance of the antenna for wideband operation and stable radiation pattern. The antenna has the low-profile structure and small dimension of 38 x35 x1.6 mm(3) giving an impedance bandwidth ranging from 2.47 to 14.31 GHz for Voltage Standing Wave Ratio (VSWR) < 2 and a maximum gain of 3.9 dBi and a maximum radiation efficiency of 90%. Within its operating band, the antenna exhibits stable radiation patterns. The simulated and measured results of the proposed antenna are in good agreement.