Abstract: Disclosed is an improved system and method to treat an edge of a material for determining a property of such material through measurements of electromagnetic waves. The system and method are operative to mitigate the adverse effects caused by the interaction between an electromagnetic wave and an edge of a sample of a material under test. The system and method define a configuration to block and significantly attenuate the propagation of electromagnetic waves that may reach an edge of the sample being evaluated. This configuration reduces the undesired effects caused by edge-diffraction that may interfere with the measurement of desired electromagnetic waves for material evaluation. As a result, a property of a material under test can be measured more accurately, especially near the edges of such material. In addition, the system and method enable the evaluation of a small-size sample of a material.

Abstract: Disclosed is an improved system and method to evaluate the status of a material. The system and method are operative to identify flaws and measure the erosion profile and thickness of different materials, including refractory materials, using electromagnetic waves. The system is designed to reduce a plurality of reflections, associated with the propagation of electromagnetic waves launched into the material under evaluation, by a sufficient extent so as to enable detection of electromagnetic waves of interest reflected from remote discontinuities of the material. Furthermore, the system and method utilize a configuration and signal processing techniques that reduce clutter and enable the isolation of electromagnetic waves of interest. Moreover, the launcher is impedance matched to the material under evaluation, and the feeding mechanism is designed to mitigate multiple reflection effects to further suppress clutter.

Abstract: Disclosed is an improved system and method to treat an edge of a material for determining a property of such material through measurements of electromagnetic waves. The system and method are operative to mitigate the adverse effects caused by the interaction between an electromagnetic wave and an edge of a sample of a material under test. The system and method define a configuration to block and significantly attenuate the propagation of electromagnetic waves that may reach an edge of the sample being evaluated. This configuration reduces the undesired effects caused by edge-diffraction that may interfere with the measurement of desired electromagnetic waves for material evaluation. As a result, a property of a material under test can be measured more accurately, especially near the edges of such material. In addition, the system and method enable the evaluation of a small-size sample of a material.

Abstract: Disclosed is an improved system and method to evaluate the status of a material. The system and method are operative to identify flaws and measure the erosion profile and thickness of different materials, including refractory materials, using electromagnetic waves. The system is designed to reduce a plurality of reflections, associated with the propagation of electromagnetic waves launched into the material under evaluation, by a sufficient extent so as to enable detection of electromagnetic waves of interest reflected from remote discontinuities of the material. Furthermore, the system and method utilize a configuration and signal processing techniques that reduce clutter and enable the isolation of electromagnetic waves of interest. Moreover, the launcher is impedance matched to the material under evaluation, and the feeding mechanism is designed to mitigate multiple reflection effects to further suppress clutter.

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: A method for determining a physical property of an object in a multi-path clutter environment comprises transmitting an RF interrogation signal to a wireless sensor physically coupled to the object or the fluid in the 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 transmit the reference signal and the measurement signal in the 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 transmitted reference signal and the transmitted measurement signal and comparing them in the time domain in order to determine the unknown physical property of the object or the fluid.

Abstract: Antenna assemblies and corresponding modes of operation are provided where the first antenna assembly of the system is tuned to a first frequency band ?1 and the second antenna assembly of the antenna system is tuned to a second frequency band ?2. The ground plane of the first antenna assembly is configured as a frequency selective surface that is substantially reflective of radiation in the first frequency band and substantially transparent to radiation in the second frequency band. The second ground plane may also be configured as a frequency selective surface and may be reflective of radiation in the second frequency band. Any number of additional antenna arrays may be added so long as the outer arrays are transparent to the inner arrays.

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: A method for detecting an object using a transmitting antenna and an array of receiving antennas. The method comprises the step of transmitting a signal from the transmitting antenna. The magnitude and phase of a respective received signal at each of the receiving antennas is then measured. Next, the magnitude of a weighted sum of respective phase-compensated signals related to each of the receiving antennas is determined. The magnitude of the weighted sum is compared against a first predetermined threshold value and, optionally, a second predetermined threshold value. An object may be detected by considering a ratio of the magnitude of the weighted sum to the first predetermined threshold value and, optionally, to the second predetermined threshold value. In some embodiments, a second array of receiving antennas may be provided to facilitate the determination of the location of the object.

Abstract: Antenna assemblies and corresponding modes of operation are provided where the first antenna assembly of the system is tuned to a first frequency band ?1 and the second antenna assembly of the antenna system is tuned to a second frequency band ?2. The ground plane of the first antenna assembly is configured as a frequency selective surface that is substantially reflective of radiation in the first frequency band and substantially transparent to radiation in the second frequency band. The second ground plane may also be configured as a frequency selective surface and may be reflective of radiation in the second frequency band.

Abstract: A radar system that utilizes predetermined, pseudorandom, or random waveforms that may be substantially matched to the impulse response of the radar and any surrounding clutter such that the signal-to-clutter ratio may be optimized and/or such that specific targets may be identified and/or classified.

Abstract: A region in a metallic panel that facilitates the transmission of radio frequency signals. The metallic panel may be included in a window such as the window of a vehicle or building. For example, the metallic panel may be used for heating or to reflect infrared radiation. An aperture is formed in the metallic panel to enable radio frequency signals to be transmitted through the metallic panel. The design of the aperture may be selected to enable the transmission of the desired frequency band. In an embodiment in which the metallic panel is used to conduct electric current, the aperture may be oriented such that the current may flow between the openings of the aperture. Accordingly, there may be uniform heating across the metallic panel without blocking the transmission of radio frequency signals in the desired frequency band.

Abstract: A radar system that utilizes predetermined, pseudorandom, or random waveforms that may be substantially matched to the impulse response of the radar and any surrounding clutter such that the signal-to-clutter ratio may be optimized and/or such that specific targets may be identified and/or classified.

Abstract: A region in a metallic panel that facilitates the transmission of radio frequency signals. The metallic panel may be included in a window such as the window of a vehicle or building. For example, the metallic panel may be used for heating or to reflect infrared radiation. An aperture is formed in the metallic panel to enable radio frequency signals to be transmitted through the metallic panel. The design of the aperture may be selected to enable the transmission of the desired frequency band. Furthermore, the aperture is designed such that there is a taper in the transmission amplitude and/or the phase to suppress lobing effects on the other side of the aperture. In an embodiment in which the metallic panel is used to conduct electric current, the aperture may be oriented such that the current may flow between the openings of the aperture. Accordingly, there may be uniform heating across the metallic panel without blocking the transmission of radio frequency signals in the desired frequency band.

Abstract: The present invention is a radar system for detecting the presence of obstacles. The radar system includes at least one transmitting antenna and at least one receiving antenna. The transmitting antenna receives an input signal and transmits an electromagnetic wave. The electromagnetic wave reflects off an obstacle back to the receiving antenna. The receiving antenna captures the reflected electromagnetic wave and produces an output signal. The output signal is then combined with the input signal in a quadrature mixer. The resulting in-phase (I) and quadrature (Q) signals may be further processed and then transmitted to a processing system. The processing system uses a suitable algorithm, e.g., a back projection algorithm, to estimate the type and location of obstacles that reflected the electromagnetic wave. In an exemplary embodiment, the algorithm is adapted to discriminate between different sizes and locations of obstacles in order to determine if there is a hazard.