Abstract: A system for pulse based wideband signaling comprises a transmitter that performs physical layer encoding of both digital and analog data into a pulse repetition rate signal, and modulation of the pulse repetition rate signal into wideband radio frequency pulses, and transmission of the pulses as a wideband RF signal, a receiver that performs physical layer demodulation of the wideband RF signal into a pulse repetition rate signal, and decoding of the pulse repetition rate signal into digital and analog data, wherein the system provides improvement in controlling and balancing the variables of bandwidth, signal to noise ratio, range, and power consumption.

Abstract: A single Vivaldi antenna plate (half Vivaldi antenna) over a ground plane can be used to achieve a 50-ohm impedance, or two or more single plates over a ground plane to achieve other impedances. Unbalanced 50-ohm transmission lines, e.g., coaxial cables, can be used to directly feed the antenna.

Abstract: A secure passive RFID tag system comprises at least one base station and at least one passive RFID tag. The tag includes a fiber optic cable with the cable ends sealed within the tag and the middle portion forming an external loop. The loop may be secured to at least portions of an object. The tag transmits and receives an optical signal through the fiber optic cable, and the cable is configured to be damaged or broken in response to removal or tampering attempts, wherein the optical signal is significantly altered if the cable is damaged or broken. The tag transmits the optical signal in response to receiving a radio signal from the base station and compares the transmitted optical signal to the received optical signal. If the transmitted optical signal and the received optical signal are identical, the tag transmits an affirmative radio signal to the base station.

Abstract: A smart passive RFID reader includes an RFID reader, a microcontroller providing a means for increasing the probability of detecting correct passive RFID tags and decreasing the probability of detecting incorrect passive RFID tags, and antennas connected to the RFID reader, wherein adjacent antennas have orthogonal polarization and the antennas each have a pivoting axis, whereby rotating the antennas about their pivoting axes causes a change in the overlap of the antenna beam radiation patterns and thereby provides a means for adaptive beamforming in order to improve tag reading.

Abstract: Two or more Vivaldi antennas, consisting of two plates each, each with the antenna's natural impedance of approximately 100 ohms, are placed in parallel to achieve a 50 ohm impedance in the case of two antennas or other impedances (100/n ohms) for more than two antennas. A single Vivaldi antenna plate (half Vivaldi antenna) over a ground plane can also be used to achieve a 50 ohm impedance, or two or more single plates over a ground plane to achieve other impedances. Unbalanced 50 ohm transmission lines, e.g. coaxial cables, can be used to directly feed, the dual Vivaldi (four plate) antenna in a center fed angled center departure, or more desirably, a center fed offset departure configuration.

Abstract: A smart passive RFID reader includes an RFID reader module, a microcontroller providing a means for increasing the probability of detecting correct passive RFID tags and decreasing the probability of detecting incorrect passive RFID tags, and antennas connected to the RFID reader module, wherein adjacent antennas have orthogonal polarization and the antennas each have a pivoting axis, whereby rotating the antennas about their pivoting axes causes a change in the overlap of the antenna beam radiation patterns and thereby provides a means for adaptive beamforming in order to improve tag reading.

Abstract: A circuit board anti-tamper mechanism comprises a circuit board having a frangible portion, a trigger having a trigger spring, a trigger arming mechanism actuated by the trigger wherein the trigger arming mechanism is initially non-actuated, a force producing mechanism, a latch providing mechanical communication between the trigger arming mechanism and the force producing mechanism, wherein the latch initially retains the force producing mechanism in a refracted position. Arming pressure applied to the trigger sufficient to overcome the trigger spring force will actuate the trigger arming mechanism, causing the anti-tamper mechanism to be armed. Subsequent tampering with the anti-tamper mechanism results in a decrease of pressure on the trigger below the trigger spring force, thereby causing the trigger arming mechanism to actuate the latch, thereby releasing the force producing mechanism to apply force to the frangible portion of the circuit board, thereby breaking the circuit board.

Abstract: A secure optionally passive RFID tag or sensor system comprises a passive RFID tag having means for receiving radio signals from at least one base station and for transmitting radio signals to at least one base station, where the tag is capable of being powered exclusively by received radio energy, and an external power and data logging device having at least one battery and electronic circuitry including a digital memory configured for storing and recalling data. The external power and data logging device has a means for powering the tag, and also has a means.