Patent ID: 6373253
Filing Date: 2002-04-16
Classification: G01V

Abstract:
Apparatus for detecting components of a time-varying electric field, including fields having a frequency in the range of about 1 MHz to about 100 MHz, comprising:a compact toroidal antenna; a voltage detector connected to the toroidal antenna to detect an induced voltage proportional to a component of the electric field perpendicular to the plane of the toroidal antenna at the center of the toroidal antenna; wherein the toroidal antenna comprises: a toroid; a multi-turn continuous uniform winding around the toroid, the voltage detector being connected to the winding to detect a voltage induced therein by a time-varying magnetic field associated with the time-varying electric field; and further wherein the electric field component Eio in the i-direction at the center of the toroidal antenna is given by Eio=V/[k2NDA] where V is the measured voltage induced in the toroidal antenna, k is the propagation constant of the toroid, N is the number of loops or turns in the winding per quadrant of the toroid (4N total turns), D is the diameter of the toroid, and A is the cross-sectional area of the toroid and each loop or turn of the winding.