Abstract: An antenna array feed network includes two or more antenna elements, a 180° hybrid coupler, one or more combiners, two or more transceiver systems including a secondary transceiver system with a transceiver, a diplexer, and amplifier with each remaining transceiver system including a transceiver, a diplexer, a directional coupler, a RF switch, a preamplifier, a network circulator, a programmable attenuator, and an amplifier. The two or more antenna elements form an antenna array. The 180° hybrid coupler provides amplitude controlled null steering and two separate RF signals for an individual port of the antenna array. The programmable attenuator provides automated null steering algorithms for the antenna array feed network. The analog phase shifter equalizes magnitudes of a phase of the two more antenna elements. The one or more combiners feed two or more transceiver systems into the 180° hybrid coupler or the antenna elements into the 180° hybrid coupler.

Abstract: An antenna array feed network includes two or more antenna elements, a 180° hybrid coupler, one or more combiners, two or more transceiver systems including a secondary transceiver system with a transceiver, a diplexer, and amplifier with each remaining transceiver system including a transceiver, a diplexer, a directional coupler, a RF switch, a preamplifier, a network circulator, a programmable attenuator, and an amplifier. The two or more antenna elements form an antenna array. The 180° hybrid coupler provides amplitude controlled null steering and two separate RF signals for an individual port of the antenna array. The programmable attenuator provides automated null steering algorithms for the antenna array feed network. The analog phase shifter equalizes magnitudes of a phase of the two more antenna elements. The one or more combiners feed two or more transceiver systems into the 180° hybrid coupler or the antenna elements into the 180° hybrid coupler.

Abstract: An antenna comprising: a loop made of conductive material; two baluns connected to, and intersecting, opposing sides of the loop, wherein each balun has an output; a 180° hybrid coupler having two input ports, a sum output port, and a delta output port, wherein the two input ports are connected to the outputs of the baluns; a first low noise amplifier (LNA) connected to the sum output port; a second LNA connected to the delta output port; first and second receivers connected to the first and second LNAs respectively; and wherein the antenna is electrically small and is designed to simultaneously receive wideband signals in real time from 3 to 30 MHz.

Abstract: An antenna comprising: a loop made of conductive material; two baluns connected to, and intersecting, opposing sides of the loop, wherein each balun has an output; a 180° hybrid coupler having two input ports, a sum output port, and a delta output port, wherein the two input ports are connected to the outputs of the baluns; a first low noise amplifier (LNA) connected to the sum output port; a second LNA connected to the delta output port; first and second receivers connected to the first and second LNAs respectively; and wherein the antenna is electrically small and is designed to simultaneously receive wideband signals in real time from 3 to 30 MHz.

Abstract: Methods for remote detection of humans can include the step of transmitting vertically polarized electromagnetic signals into an area of interest (AOI) when no humans are present. A first time domain measurement of return response signal energy from the AOI can be accomplished to establish a background signal. A second time domain measurement of response signal energy from the AOI can be made when at least one human is present, to establish a background-plus-human signal. The two signals can be subtracted to yield a reference time domain human signal. The electromagnetic signal is periodically re-transmitted. The background subtracted from subsequent response energy, and the result compared to the reference time domain human signal. A visual or audible indication occurs when the resulting signal matches the reference signal. Fast Fourier Transforms (FFT) of the time domain signals can be used to yield frequency responses, which can be monitored.

Abstract: An apparatus for remotely detecting metal objects carried by a person includes an antenna and a signal generator coupled to the antenna operable to cause the antenna to emit a first electromagnetic signal to the person at a frequency that is known to be resonant with the human body. The apparatus further includes a data capture device operable to capture response signal energy received by the antenna, the response signal energy being provided from the person in response to the first electromagnetic signal. Processing circuitry for the apparatus is operable to determine whether the response signal energy is indicative whether or not the person is carrying an appreciable amount of metal, based on reference response templates for persons that are known to be metal-free.