Radiation from groove-backed antennas with a gap

In a ground penetrating radar system, there is inevitably a gap between the antennas and ground surface. The presence of a gap strongly influences the antenna radiation and the coupling mechanism between the transmitting and receiving antennas. The radiation and coupling between two groove-backed antennas is investigated when a gap is present between the ground and antenna. The boundary conditions are used to constitute simultaneous equations for discrete modal coefficients. The characteristics of coupling reduction and radiation are illustrated in terms of antenna geometries.