Ground Plane Proximity Effects in Three-Loop Antenna Systems

Three-loop antenna systems (TLASs) are one of the few sensors with the ability to simultaneously detect centrally located electric and magnetic dipole moment vectors. The theory of TLASs ignores the presence of ground planes and assumes that the responses comprise those of single dual-loaded loops in isolation. This paper investigates the ground plane proximity effects for the cases of centrally located electric or magnetic dipole moment sources, as a function ground plane separation distance. It is shown through simulations that the responses of the TLAS sensor are not significantly affected by the presence of a ground plane which is parallel to one of the loops. The only appreciable impact is that the margin of the source type discrimination decreases as the ground plane approaches the TLAS.