Design of a Wideband Antenna for a Narrow Borehole Radar Using FDTD Modeling

For the design of a narrow wideband antenna (with diameter less than 3 cm) to serve in a borehole radar in the band [0.5,1.5] GHz for moisture content measurements, we have considered five different geometries. These geometries have been modeled using the finite-difference time-domain approach. The frequency- and time-domain responses have been analyzed in detail in the transmission configuration in the presence of a dielectric soil. We present radargrams for the multiple offset gather configuration. This study will help to define the best antenna geometry for the present application.