Abstract: An embodiment of an antenna system comprising a radio frequency (RF) current-sensing and current injecting antenna device for coupling RF energy, wherein the antenna device comprises an outer conducting non-magnetic housing, a magnetic core having a central aperture, said core insulated from said housing, and a first winding wound about said core, said first winding having a first end receiving said RF energy and a second end, said first winding insulated from said housing between said first end and said second end, wherein a conductor is positioned within said aperture, and said conductor has a length of at least 0.1 wavelength of said RF energy. Wherein, in a transmitting mode said antenna device couples RF energy, created in an RF transmitter, to the conductor. In a receiving mode said antenna device couples RF energy, developed in the conductor intercepting an RF field, to the input of an RF receiver.

Abstract: Controlling the common mode impedance for a circuit, conductor, or multiple conductor cable by incorporating the circuit or conductor into the primary of a transformer. The secondary of the transformer is coupled to a secondary impedance selected so that the desired impedance is obtained. A capacitive shunt may be added to buffer the intrinsic primary impedance. The intrinsic impedance of a conductive antenna structure is controlled by deploying a portion of the antenna structure as the primary of a transformer and coupling the secondary of the transformer to a selectable secondary impedance.

Abstract: Controlling the common mode impedance for a circuit, conductor, or multiple conductor cable by incorporating the circuit or conductor into the primary of a transformer. The secondary of the transformer is coupled to a secondary impedance selected so that the desired impedance is obtained. A capacitive shunt may be added to buffer the intrinsic primary impedance. The intrinsic impedance of a conductive antenna structure is controlled by deploying a portion of the antenna structure as the primary of a transformer and coupling the secondary of the transformer to a selectable secondary impedance.