Design of Elliptical to Circular Dielectric Resonator Antenna for Microwave Imaging Application

In this article, a stacked elliptical to circular shape Dielectric Resonator Antenna (DRA) is designed to act as sensor in breast tumor detection in the imaging (MWI) technique. The novelty of the proposed article is different size of elliptical to circular shape DRA is excited by inset feed mechanism. Two different iterations are followed to improve the performance by varying the elliptical dielectric structure of dimensions in the x-axis by = 3mm, 6mm. Later, circular DRA of radius 9mm is proposed to improve the bandwidth of the antenna. The DRA substrate layer is designed using FR4 material (εr=4.2) and the elliptical dielectrics iterations are made of alumina (εr=9.8). In addition the improvement in bandwidth is due the invasion of wheel structure in the ground plane. From the result it is observed that the antenna resonates at nearly 1.7 GHz, 2.4 GHz, 3.7GHz and 10.1GHz which comes under X-band, S band and L-band frequency range. A significant variation of return loss is identified in the analysis when the dielectric structure is varied from elliptical to circular structure.