Abstract: A method and apparatus for detecting an object. A first collimated beam having a first frequency and a second collimated beam having a second frequency is transmitted. At least one of the first frequency and the second frequency is changed through a range of frequencies and a power level for at least one of the first collimated beam and the second collimated beam is changed through a range of power levels. A range of fundamental difference frequency signals for each power level in the range of power levels are monitored for, in response to transmitting the first collimated beam and the second collimated beam using the range of frequencies and the range of power levels. The range of fundamental difference frequency signals is generated by the object having non-linear electrical characteristics in response to receiving the first collimated beam and the second collimated beam.

Abstract: In embodiments a system to generate a dual frequency, circularly polarized beam of rotating electromagnetic radiation comprises a first radiation source to generate a first radiation beam at a first frequency, a second radiation source to generate a second radiation beam at a second frequency, different from the first frequency, and a tee. In some embodiments the tee receives the first radiation beam and the second radiation beam, outputs a third radiation beam which represents a sum of the first radiation beam and the second radiation beam, and outputs a fourth radiation beam which represents a difference between the first radiation beam and the second radiation beam, wherein the third radiation beam and the fourth radiation beam are separated by a ninety-degree phase shift. The system further comprises a combiner to combine the third and fourth beams to produce an output beam. Other embodiments may be described.

Abstract: A method and apparatus for detecting non-linear tags. In one advantageous embodiment a system for detecting non-linear tags has a transmitter and a receiver. The transmitter transmits a plurality of electromagnetic signals having a first frequency and a second frequency. The receiver monitors for an electromagnetic signal having a frequency equal to a difference between the first frequency and a second frequency that is generated by a non-linear tag in response to receiving the plurality of electromagnetic signals, wherein the non-linear tag is detected when the electromagnetic signal is detected by the receiver.

Abstract: A method and apparatus for detecting objects located underground. In one advantageous embodiment, a detection system detects objects having electrical non-linear characteristics located underground. The detection system comprises a transmitter unit, a receiver, and a processor. The transmitter transmits a plurality of pulsed radio frequency signals having a first frequency and a second frequency into a ground. The receiver monitors for a response radio frequency signal having a frequency equal to a difference between the first frequency and a second frequency, wherein the response radio frequency signal is generated by an object having the non-linear conductive characteristics in response to receiving the plurality of electromagnetic signals. The processor is connected to the transmitter unit and the receiver, wherein the processor controls an operation of the transmitter unit and the receiver, wherein the object is detected when the response radio frequency signal is detected by the receiver.

Abstract: A method and apparatus for detecting objects located underground. In one advantageous embodiment, a detection system detects objects having electrical non-linear characteristics located underground. The detection system comprises a transmitter unit, a receiver, and a processor. The transmitter transmits a plurality of pulsed radio frequency signals having a first frequency and a second frequency into a ground. The receiver monitors for a response radio frequency signal having a frequency equal to a difference between the first frequency and a second frequency, wherein the response radio frequency signal is generated by an object having the non-linear conductive characteristics in response to receiving the plurality of electromagnetic signals. The processor is connected to the transmitter unit and the receiver, wherein the processor controls an operation of the transmitter unit and the receiver, wherein the object is detected when the response radio frequency signal is detected by the receiver.

Abstract: A method and apparatus for detecting non-linear tags. In one advantageous embodiment a system for detecting non-linear tags has a transmitter and a receiver. The transmitter transmits a plurality of electromagnetic signals having a first frequency and a second frequency. The receiver monitors for an electromagnetic signal having a frequency equal to a difference between the first frequency and a second frequency that is generated by a non-linear tag in response to receiving the plurality of electromagnetic signals, wherein the non-linear tag is detected when the electromagnetic signal is detected by the receiver.

Abstract: In one embodiment a system to detect, from a remote location, one or more wires in a target location comprises a radiation targeting assembly to direct a rotating polarization radiation field at the target location, a reflected radiation collecting assembly that collects radiation reflected from the target location, and a signal processing module to monitor radiation from the rotating radiation field reflected from the target location and generate a signal when the radiation reflected from the target location indicates the presence of a wire in the target location. Other embodiments may be described.

Abstract: A system and method can use a transmission line to remotely detect border violations. For example, the transmission line can be configured to use time domain reflectometry to determine when a person and/or object crosses a border. The border can be the border of a country or the perimeter of a facility such as an airport, for example.

Abstract: A composite dipole array assembly can have a composite dipole array defined by a plurality of antenna elements and a plurality of non-linear element electrically interconnecting pair of the antenna elements. A reflector can be configured to reflect electromagnetic energy toward the antenna elements. A lens can be configured to focus electromagnetic energy upon the antenna elements. In this manner, the efficiency of the composite dipole array is enhanced.

Abstract: An electromagnetic radiation filter uses a plurality of dipole antennas to mitigate the transmission of electromagnetic radiation. The dipole antennas can form one or more arrays that scatter electromagnetic radiation. Examples of application include mitigating the reception of a difference frequency in non-linear radar, use in protective goggles, and use in a protective shield.

Abstract: An apparatus comprises a transmitter system, a receiver system, and a processor unit. The transmitter system transmits first and second collimated beams having a first and second frequency. The receiver system monitors for a fundamental difference frequency signal having a difference frequency equal to a difference between the first and second frequency and a number of harmonics of the fundamental difference frequency signal. These signals are generated by an object having non-linear electrical characteristics in response to the collimated beams. The processor unit is connected to the transmitter system and the receiver system. The processor unit controls the transmitter and receiver systems to change at least one of the first and second frequencies through a range of frequencies and detect a range of fundamental difference frequency signals and the number of harmonics of the fundamental difference frequency signal in response to transmitting the collimated beams using the range of frequencies.

Abstract: A method and apparatus for transmitting beams of electromagnetic energy. A plurality of beams having a first number of frequencies and a number of beams having a second number of frequencies are transmitted. The plurality of beams and the number of beams overlap each other at an area with a pattern of intensities in the area. Difference frequency signals having a number of difference frequencies equal to a difference between the first number of frequencies and the second number of frequencies are monitored. The difference frequency signals are generated by an object having non-linear electrical characteristics in response to receiving the plurality of beams and the number of beams.

Abstract: A transmitter system can have a higher power transmitter and a lower power that are configured to transmit a pair of unbalanced radio frequency beams to a target so as to produce a difference frequency in the target. The difference frequency can disrupt operation of a device, such as a weapon. The difference frequency can provide a radar return. The use of a higher power transmitter and a lower power transmitter reduces costs, size, and weight as compared to the use of two higher power transmitters.

Abstract: In one embodiment a system to detect, from a remote location, one or more wires in a target location comprises a radiation targeting assembly to direct a rotating polarization radiation field at the target location, a reflected radiation collecting assembly that collects radiation reflected from the target location, and a signal processing module to monitor radiation from the rotating radiation field reflected from the target location and generate a signal when the radiation reflected from the target location indicates the presence of a wire in the target location. Other embodiments may be described.

Abstract: A method and apparatus for transmitting beams of electromagnetic energy. A plurality of beams having a first number of frequencies and a number of beams having a second number of frequencies are transmitted. The plurality of beams and the number of beams overlap each other at an area with a pattern of intensities in the area. Difference frequency signals having a number of difference frequencies equal to a difference between the first number of frequencies and the second number of frequencies are monitored. The difference frequency signals are generated by an object having non-linear electrical characteristics in response to receiving the plurality of beams and the number of beams.

Abstract: A detection system comprises a transmitter unit, a receiver, and a processor. The transmitter unit is capable of transmitting a first collimated beam having a first frequency and a second collimated beam having a second frequency into a ground, wherein the first collimated beam and the second collimated beam overlap in the ground. The receiver is capable of monitoring for a response radio frequency signal having a frequency equal to a difference between the first frequency and the second frequency. The response radio frequency signal is generated by an object having non-linear conductive characteristics in response to receiving the first collimated beam and the second collimated beam. The processor is capable of controlling an operation of the transmitter unit and the receiver. The processor is connected to the transmitter unit and the receiver. The object is detected when the response radio frequency signal is detected by the receiver.

Abstract: A broadband composite dipole array (CDA) includes an array of macro dipoles on a non-conducting substrate adapted to receive radiation at two frequencies. Each macro dipole is an array of micro dipoles adapted to receive radiation at substantially the mean of the two frequencies. The micro-dipoles are coupled to each other by a parallel resonant circuit including a nonlinear element, wherein the minimum impedance of the circuit is a substantially short circuit at the difference frequency f1?f2, and the circuit has a substantially open circuit impedance in the range of frequencies from f1 to f2. The micro dipoles resonate efficiently at both frequencies f1 and f2 with low-loss. The nonlinear element in the resonant circuit generates a signal at the difference frequency which is the resonant frequency of the macro dipole antenna.

Abstract: A method and system for remotely affecting electronics within a conductive enclosure are disclosed. The method can comprise transmitting electromagnetic radiation of two different frequencies to the enclosure. The two different frequencies can be selected such that they penetrate the enclosure and therein form electromagnetic radiation of a third frequency that resonates within the enclosure. The third frequency can interact with the electronics, such as to disrupt operation thereof.

Abstract: A transmitter system can have a higher power transmitter and a lower power that are configured to transmit a pair of unbalanced radio frequency beams to a target so as to produce a difference frequency in the target. The difference frequency can disrupt operation of a device, such as a weapon. The difference frequency can provide a radar return. The use of a higher power transmitter and a lower power transmitter reduces costs, size, and weight as compared to the use of two higher power transmitters.

Abstract: An electromagnetic radiation filter uses a plurality of dipole antennas to mitigate the transmission of electromagnetic radiation. The dipole antennas can form one or more arrays that scatter electromagnetic radiation. Examples of application include mitigating the reception of a difference frequency in non-linear radar, use in protective goggles, and use in a protective shield.