Resistively-loaded Vee antennas for short-pulse ground penetrating radar

A short-pulse, ground penetrating radar (GPR) requires a broadband, directive antenna to transmit a pulse into a small spot on the ground. Distributed resistive loading has been used to extend the bandwidth of dipoles to allow pulse radiation. However, these antennas are not very directive. As an alternative, we consider resistive Vee antennas. The Vee retains the simplicity of the dipole while significantly increasing the directivity. The method of moments with an IDFT was used to evaluate the performance of these antennas in the time domain. We consider a monostatic radar where the antenna radiates a pulse which is reflected from the surface of the ground and the buried target, and the reflected pulse is received by the antenna. For a successful design, the voltage reflected at the drive point should be small and the received signal should be as large as possible. Multiple reflections (ringing) between the surface of the ground and the antenna should be minimized, so that the reflection from the buried target is not obscured. In addition, the spot illuminated on the ground should be small in order that the position of the target can be resolved.