An Antipodal Vivaldi Antenna for a Drone-Mounted Ground Probing Radar

An antenna operating between 300 MHz and 700 MHz, designed to be used on a ground penetrating radar installed on an Unmanned Aerial Vehicle (UAV) for the exploration and characterization of the buried ice deposits on Mars, is presented. To this end, a lightweight, high-gain Vivaldi antenna having compact dimensions and high operating bandwidth has been taken into consideration. This antenna, equipped with circular-loaded rectangular slots etched on its radiating arms, exhibits improved performance in terms of size, return loss, gain, and fidelity factor with respect to a conventional antipodal Vivaldi antenna. Experimental measurements performed on a prototype of the Vivaldi antenna with slots showed a return loss lower than −12 dB with realized gains between 4 dBi and 6.5 dBi in the 300–700 MHz frequency band.