Patent ID: 8704721
Filing Date: 2014-04-22
Classification: G06K,H01Q,Y10T

Abstract:
1. An antenna system for use with very low frequency or low frequency RF tag systems, the antenna system comprising: a plurality of ferrite core primary coils, each of the ferrite core primary coils has a longitudinal axis being at an angle with respect to each other; and a secondary coil disposed around at least one of the ferrite core primary coils, wherein the ferrite core primary coils are in series and coupled to a capacitive element to form a resonant circuit and wherein the capacitive element comprises a variable capacitor coupled between an end of one of the ferrite core primary coils and an end of another of the ferrite core primary coils, wherein the variable capacitor is a varactor diode, a multi-turn trim capacitor, or a single turn capacitor.