Abstract: A method for determining a physical property of an object or fluid in a dynamic multi-path clutter environment comprises transmitting an RF interrogation signal to a wireless sensor physically coupled to the object or fluid (gas or liquid) in the dynamic multi-path clutter environment, wherein the wireless sensor is operable to receive the RF interrogation signal, produce a reference signal and a measurement signal, and retransmit the reference signal and the measurement signal in the dynamic multi-path clutter environment. The reference signal and measurement signal are delayed by the wireless sensor by an amount of time that may be a function of the unknown physical property. The method also comprises receiving the retransmitted reference signal and the retransmitted measurement signal and comparing them in the time domain in order to determine the unknown physical property of the object or fluid.

Abstract: A method for determining a physical property of an object or fluid in a dynamic multi-path clutter environment comprises transmitting an RF interrogation signal to a wireless sensor physically coupled to the object or fluid (gas or liquid) in the dynamic multi-path clutter environment, wherein the wireless sensor is operable to receive the RF interrogation signal, produce a reference signal and a measurement signal, and retransmit the reference signal and the measurement signal in the dynamic multi-path clutter environment. The reference signal and measurement signal are delayed by the wireless sensor by an amount of time that may be a function of the unknown physical property. The method also comprises receiving the retransmitted reference signal and the retransmitted measurement signal and comparing them in the time domain in order to determine the unknown physical property of the object or fluid.

Abstract: An antenna made up of small addressable conductive segments, or pixel elements, located in a dielectric space positioned over a two-dimensional pixel element actuator is presented. The small pixel elements can be actuated in less than a millisecond by the actuator to form patterns that create an array of patch antennas and associated transmission lines on the upper surface of the dielectric space. The pixel elements can be formed using small movable conductive particles such as metal flakes or metal chips.

Abstract: An antenna made up of small addressable conductive segments, or pixel elements, located in a dielectric space positioned over a two-dimensional pixel element actuator is presented. The small pixel elements can be actuated in less than a millisecond by the actuator to form patterns that create an array of patch antennas and associated transmission lines on the upper surface of the dielectric space.

Abstract: A method for determining a physical property of a structural member in a dynamic multi-path clutter environment is given. The method comprises transmitting an RF interrogation signal to a wireless sensor operable to receive the RF interrogation signal, produce a reference signal and a measurement signal, and transmit the reference signal and the measurement signal in the dynamic multi-path clutter environment. The reference signal is delayed by a first time delay and the measurement signal is delayed by a second time delay that is a function of the physical property to be determined. The first and second time delays are associated by a known relationship defined by the wireless sensor. The method further comprises receiving the transmitted reference signal and the transmitted measurement signal and comparing the transmitted reference signal and the transmitted measurement signal in the time domain. Finally, the method comprises using this comparison to determine the physical property of the structural member.

Abstract: An antenna made up of addressable conductive segments, or pixel elements, affixed to the top of each piston in a piston array is presented. The pixel elements can be activated in less than a millisecond to form an antenna array and transmission line pattern using movable pistons and a two-dimensional actuator. Each piston comprises a handle, a bottom conductive segment affixed to the top of the handle, a dielectric segment affixed to the uppermost surface of the bottom conductive segment, and a top conductive segment affixed to the uppermost surface of the dielectric segment. When the piston is not actuated, the top conductive segment forms part of a ground plane. The top conductive segment form part of the transmission line and antenna array patterns, the dielectric segment becomes a dielectric space and the bottom conductive segment forms part of the ground plane when the piston is actuated.

Abstract: An antenna made up of addressable conductive segments, or pixel elements, affixed to the top of each piston in a piston array is presented. The pixel elements can be activated in less than a millisecond to form an antenna array and transmission line pattern using movable pistons and a two-dimensional actuator. Each piston comprises a handle, a bottom conductive segment affixed to the top of the handle, a dielectric segment affixed to the uppermost surface of the bottom conductive segment, and a top conductive segment affixed to the uppermost surface of the dielectric segment. When the piston is not actuated, the top conductive segment forms part of a ground plane. The top conductive segment form part of the transmission line and antenna array patterns, the dielectric segment becomes a dielectric space and the bottom conductive segment forms part of the ground plane when the piston is actuated.

Abstract: An ensemble clock comprises: an input for receiving a reference signal; multiple free-running oscillators each configured to generate a corresponding free-running frequency; an output oscillator configured to generate a controlled frequency having a frequency responsive to a control signal; a differencer unit configured to derive difference measurements indicative of time and frequency-based errors associated with each of (i) the controlled frequency, and (ii) the free-running frequency, relative to the reference signal; and a controller configured to generate the control signal responsive to the difference measurements.