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: 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: 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: 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: 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 terahertz spectroscopy system includes a source of terahertz radiation, a detector of terahertz radiation, a source of sample gas, and a sample cell that can be cooled to cryogenic temperatures. The sample cell may be configured to receive the sample gas, received terahertz radiation from the source of terahertz radiation, provide the terahertz radiation to the detector after the terahertz radiation has passed through the sample gas, and facilitate cryogenic cooling thereof. The sample cell may be cryogenically cooled to freeze the sample gas and subsequently warmed either continuously or in steps in temperature so that individual components or groups of components of the sample gas may evaporate and thus have absorption spectra formed therefor. Enhanced resolution of absorption spectra is provided when a gas sample contains a large number of components of different gases.

Abstract: A terahertz spectroscopy system includes a source of terahertz radiation, a detector of terahertz radiation, a source of sample gas, and a sample cell that can be cooled to cryogenic temperatures. The sample cell may be configured to receive the sample gas, received terahertz radiation from the source of terahertz radiation, provide the terahertz radiation to the detector after the terahertz radiation has passed through the sample gas, and facilitate cryogenic cooling thereof. The sample cell may be cryogenically cooled to freeze the sample gas and subsequently warmed either continuously or in steps in temperature so that individual components or groups of components of the sample gas may evaporate and thus have absorption spectra formed therefor. Enhanced resolution of absorption spectra is provided when a gas sample contains a large number of components of different gases.

Abstract: A high-frequency two-dimensional antenna includes a plurality of dual-frequency antennas configured to receive signals having first and second frequencies above the microwave band of the electromagnetic spectrum. The dual-frequency antennas of the two-dimensional antenna are arrayed to an effective length to re-radiate signals at a third frequency, which is down-converted from the first and second frequencies. Each dual-frequency antenna of the two-dimensional antenna includes a plurality of dipole antennas, and a plurality of nonlinear resonant circuits. The nonlinear resonant circuits interconnect the dipole antennas and are configured to permit re-radiation of signals having the third frequency over the effective length. A method of down-converting signals having at least first and second electromagnetic radiation frequencies is also provided.

Abstract: A high-frequency two-dimensional antenna includes a plurality of dual-frequency antennas configured to receive signals having first and second frequencies above the microwave band of the electromagnetic spectrum. The dual-frequency antennas of the two-dimensional antenna are arrayed to an effective length to re-radiate signals at a third frequency, which is down-converted from the first and second frequencies. Each dual-frequency antenna of the two-dimensional antenna includes a plurality of dipole antennas, and a plurality of nonlinear resonant circuits. The nonlinear resonant circuits interconnect the dipole antennas and are configured to permit re-radiation of signals having the third frequency over the effective length. A method of down-converting signals having at least first and second electromagnetic radiation frequencies is also provided.

Abstract: A compact three axis ring laser gyroscope having six laser corner mirrors which are positioned on the faces of a parallelopiped laser block, and method for making. Preferably the laser block is a cube. The laser block has a plurality of conduits therein for defining a plurality of closed laser beam-paths for guiding counterpropagating laser waves. Each laser beam-path has a gain medium therein and is formed to define a sensing axis for detection of rotations of the laser block. A single cathode is positioned inside the laser block, preferably substantially at its geometric center, and a plurality of anodes are mounted to the laser block and spaced apart from the cathode. A ion flow path is formed between each anode and the cathode such that application of a suitable electrical potential difference between the anodes and the cathode produces counterpropagating laser beams in each laser beam-path.