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: A TEM mode cell having an internal TEM element and at least one port on the cell comprising a stepped transmission line transformer coupling said element to the port. The cell comprises a hollow metallic housing having an enlarged center with opposite open ends, and a pair of end sections closing off said center open ends and tapering to a distal end of reduced cross sectional area. A connector at the distal end of each end section, and a stepped septum mounted within the housing and insulated therefrom, the septum coupled to and extending between the connectors. The septum having a central portion joining a pair of end portions each having a stepped contour reducing in size toward its connector. Each end portion has at least three steps in contour, with transition slopes between the steps being greatest leading to said central portion and the least leading to its connector.

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: An apparatus for, and method of, replacing conventional antennas which transmit radio frequency energy from radio frequency transmitters. The invention provides for the use of any conductive surface as a transmitting antenna by taking advantage of the fact that any electrical conductor or surface that is 0.1 wavelengths or longer will radiate RF energy when injected with sufficient current. The RF current injecting antenna device, employing the principles of an instrument transformer, couples RF energy from a transmitter to a linear conductive element or a conductive surface. The useful frequency range that has been demonstrated for the device is 2 MHz to 1 GHz.

Abstract: An apparatus for, and method of, replacing conventional antennas which intercept radio frequency fields and develop electrical signals for input to an RF receiver. The invention eliminates the use of antennas by taking advantage of the fact that any electrical conductor or surface develops significant current when its length is approximately 0.1 wavelength long or longer of an intercepted RF field. The RF current-sensing coupled antenna device, employing the principles of an instrument transformer, transforms the current in a wire filament or metallic surface and conveys it to a receiver. The useful frequency range that has been demonstrated for the coupled antenna device is 100 kHz to 2 GHz.

Abstract: A TEM mode cell having an internal TEM element and at least one port on the cell, the cell comprising a stepped transmission line transformer coupling the internal TEM element to the port. The stepped transmission line transformer of the TEM mode cell has transfer characteristics selected to give maximum cancellation of VSWR in the cell and thereby enable optimum cell bandwidth. The TEM mode test cell comprises a hollow metallic housing having an enlarged center section with opposite open ends, and a pair of end sections, each end section closing off a respective one of the center section open ends and tapering to a distal end of reduced cross sectional area. A connector is provided at the distal end of each end section, and a stepped septum is mounted within the housing and insulated therefrom, the septum coupled to and extending between the connectors.