A Compact Loaded DETSA Antenna With Enhanced Directivity Using Characteristic Modes Optimization

This paper presents the design of an Ultra Wideband (UWB) antenna mainly dedicated for Ground Penetrating Radar (GPR) application in the frequency band between 150 MHz up to 550 MHz. With its compact electrical size in the low band, the initial double exponentially tapered slot antenna (DETSA) exhibits a low directivity and Front-to-Back ratio. With the guidance of the Characteristic Modes Analysis (CMA), it was possible to identify the best loading position as well as the optimized load values to enhance these antennas properties. The optimized loaded DETSA demonstrated a significant directivity enhancement and a Front-to-Back ratio that exceeds 4dB inside the band.