Wideband loaded bicone antennas for GPR applications

The bicone antenna is known for its wideband applications. Past publications and development of this type of antenna concentrate on radiating into the air. For GPR use the antenna needs to radiate into the ground. In this work the effect of dielectric loading of the antenna to produce a better match to the ground is investigated. This is developed for both traditional GPR schemes where transmit and receive antennas are placed at or near the surface of the ground, and for the more novel in-pipe deployment where a transmitter or receiver antenna are placed in a buried pipe. Dielectric loading is seen to be beneficial in both Finite Difference Time Domain theoretical analyses and in measurements. While with optimal dielectric loading there is seen to be a benefit in reducing the direct signal between the transmitter and receiver antennas, multiple reflections within an array of dielectric loaded bicone antennas appears to present largely similar problems as an unloaded array.