Reception of dipole sources using dual-loaded loop antennas

The dual-loaded loop antenna is a canonical electromagnetic field sensor that can simultaneously measure two field components instead of the single component of a single-port dipole or loop. This thesis re-visits the formulation for the port currents on a dual-loaded loop and introduces minor modifications that are validated with simulations. It investigates performance impacts due to practical aspects, such as the presence of the other loops when the dual-loaded loop is configured as a three-loop antenna system and the proximity effects of ground planes. The theory of the dual-loaded loop is extended to cases for sensing arbitrarily located electric and magnetic dipole sources, and new general expressions are presented for the tangential electric field on a loop resulting from electric and magnetic dipole sources. These field expressions are used to derive closed-form approximations for the current at the ports. The approximations are shown to be very accurate through simulation but can degrade when the separation distance between the electric dipole source and loop is small. These expressions provide a benchmark for checking numerical and physical results for this class of sensor. Finally, a new wireless system architecture is introduced for a dual-loaded loop sensor for extremely low-frequency applications. The system was fabricated and used to validate the theory of the port currents from an offset magnetic dipole.