Design of UWB Antenna for Microwave Imaging using Modified Fractal Structure

Abstract

UWB is increasingly advancing as a high data rate wireless technology after the Federal Communication Commission announced the bandwidth of 7.5 GHz (from 3.1 GHz to 10.6 GHz) for ultra-wideband (UWB) applications. Furthermore, designing a UWB antenna faces more difficulties than designing a narrow band antenna. A suitable UWB antenna should be able to work over the Federal Communication Commission (FCC) of ultra-wide bandwidth allocation. Furthermore, good radiation properties across the entire frequency spectrum are needed. This paper presents an optimization of a modified fractal structure based on a square microstrip patch antenna with the partial ground using computer software technology (CST) simulation software for a microwave imaging application. The optimized antenna proposed a small fractal structure to meet the ultra-wideband characteristic in terms of reflection coefficient and bandwidth. The overall size of the designed antenna is 39 mm ×39mm ×1.65 mm and reduced the size by cutting the edges and the center of the patch. The optimized results reported concentrating on the rerun loss, voltage standing wave ratio (VSWR) and gain. The projected antenna is fabricated and the results are validated using measurements indicating an important enhancement. Thus, the optimized design is suitable for the microwave imaging system.