Novel circularly polarized dielectric resonator antenna for microwave image sensing application

In this article, a novel, simple, and compact structure of dielectric resonator antenna is proposed, which provides wide bandwidth across proposed mm wave band for microwave image sensing with considerable gain using a lossy FR-4 epoxy substrate and thick FR4 as DRA. A DR can be excited using four-line feed using a circular loop type feed network. These line feeds maintain phase difference of 90° to produce CP. This antenna provides approximate constant gain of 8.6 dB on 25-26 GHz band and 3 dB axial ratio bandwidth is almost 1 GHz from 25.2 to 26.2 GHz, Impedance bandwidth of the proposed antenna is 3 GHz (24-27 GHz). This antenna can be used in microwave image sensing and wearable sensors applications, due to its compactness (30 × 30 mm 2 ), in mm wave band.