Abstract: An interferometer is provided. The interferometer includes a multifaceted beamsplitter. Angles of incidence between beams entering the beamsplitter and a beamsplitting surface of the beamsplitter are less than 45 degrees. The arms of the interferometer feature a refractive compensator or a catseye optical configuration to provide an optical path length difference for rays that is the same at any location along the effective aperture of the interferometer. A detector assembly can be included with at least four detectors that lie in a plane and that receive light along paths that are orthogonal to that plane.

Abstract: Flexural pivot structures and methods are provided. A flexural pivot as disclosed allows for rotation of a pivoted member relative to a base member about a central axis, while inhibiting or preventing movement of the pivoted member relative to the base member in any other direction. Base and pivoted sections of the flexural pivot structure are connected to one another by a set of resilient blades or flexural members. A thickness of the blades varies with the distance from the central axis. The components of the flexural pivot can comprise a monolithic structure that is formed from a single piece of material.

Abstract: Suspension system structures and methods are provided. A system as disclosed allows for rotation of a supported object in two axes, with very little translational movement of the supported object. The system can include a base mounting structure that is joined to an intermediate or connecting structure by a first set of flexure blades. The connecting structure is in turn joined to a supported element structure by a second set of flexure blades. The first set of flexure blades can include four blades that intersect along a line that is coincident with an X axis of rotation, and the second set of flexure blades can include four blades that intersect along a line that is coincident with the Y axis of rotation. The components of the suspension system can comprise a monolithic structure that is formed from a single piece of material.

Abstract: A micropositioner is provided. The micropositioner can include a suspension system with a support element that is connected to a base by first and second sets of flexures. The first and second sets of flexures permit movement of the support element within first and second dimensions respectively, while preventing movement of the support element in a third dimension that is orthogonal to the first and second dimensions. More particularly, the first set of flexures can include first and second flexures that are opposite one another and configured such that movement of the support element in the first dimension is allowed, but movement of the support element in the second and third dimensions is prevented. The second set of flexures can include third and fourth flexures that are opposite to one another and configured such that movement of the support element in the second dimension is allowed, but movement in the first and third dimensions is prevented.

Abstract: A micropositioner is provided. The micropositioner can include a suspension system with a support element that is connected to a base by first and second sets of flexures. The first and second sets of flexures permit movement of the support element within first and second dimensions respectively, while preventing movement of the support element in a third dimension that is orthogonal to the first and second dimensions. More particularly, the first set of flexures can include first and second flexures that are opposite one another and configured such that movement of the support element in the first dimension is allowed, but movement of the support element in the second and third dimensions is prevented. The second set of flexures can include third and fourth flexures that are opposite to one another and configured such that movement of the support element in the second dimension is allowed, but movement in the first and third dimensions is prevented.

Abstract: An interferometer is provided. The interferometer includes a multifaceted beamsplitter. Angles of incidence between beams entering the beamsplitter and a beamsplitting surface of the beamsplitter are less than 45 degrees. The arms of the interferometer feature a refractive compensator or a catseye optical configuration to provide an optical path length difference for rays that is the same at any location along the effective aperture of the interferometer. A detector assembly can be included with at least four detectors that lie in a plane and that receive light along paths that are orthogonal to that plane.

Abstract: Systems and methods for isolating radio frequency (RF) signals in high frequency circuit assemblies, including but not limited to 5G communication systems, are provided. The circuit assemblies include an RF suppression structure, which can be in the form of a low ohm resistor, that extends across a transmission line, and that has contacts that are electrically joined to a ground plane. Alternatively or in addition, the circuit assemblies include a low ohm resistor that extends over a transition between a signal via and an end of a transmission line, and that has contacts that are electrically joined to a ground plane. A circuit assembly as disclosed herein can further include multiple low ohm resistors spaced apart from one another by a distance that is a fraction of a wavelength of a highest frequency signal carried by the transmission line.

Abstract: An antenna system circuit board stack with feed vias and with non-feed vias is disclosed. An antenna system circuit board stack as disclosed herein can include a plurality of patches or radiating elements formed on a common plane comprising a first surface of a circuit board. Each radiating element is electrically connected to one or more feed vias. In addition non-feed vias extend through, but are electrically isolated from, the radiating elements. An antenna system as disclosed herein enables the costs associated with multiple beam antenna systems, including but not limited to 5G communication systems, to be reduced as compared to alternative techniques.

Abstract: Methods and systems for remotely detecting gases and emissions of gases are provided. Data is collected from a scene using a sensor system. The data is initially optionally processed as 1D data to remove noise, and is then assigned a confidence value by processing the 1D data using a neural network. The confidence value is related to a likelihood that an emission has been detected at a particular location. The processed 1D data, including the confidence value, is gridded into 2D space. The 2D data is then processed using a neural network to assign a 2D confidence value. The 2D data can be fused with RGB data to produce a map of emission source locations. The data identifying emissions can also be processed using a neural network to determine and output emission rate data.

Abstract: A system for remotely detecting gas concentration is provided. The system includes a plurality of light sources. At least a first one of the light sources generates light having a first wavelength and a first polarization, and at least a second one of the light sources generates light having a second, different wavelength and a second polarization that is orthogonal to the first polarization. The light from the light sources is placed on a common transmission path, and is directed to a target area by a steering mirror. Light reflected from the target area is received and directed to a detector. The detector provides information regarding the time of arrival and amplitude of the received light, allowing range and gas concentration information to be obtained. In some embodiments the detector is an imaging detector, allowing three-dimensional range information to be obtained from the target area from a single light pulse.

Abstract: Free-space communication systems and methods are provided. The systems include a transmitter that combines multiple sets of radio-frequency-modulated optical carrier frequencies for transmission across free space using multiple transmission apertures. Different sets of signals are filtered to form single sideband signals. The different sets of single sideband signals are then combined to form dense wavelength division multiplexed signals. In addition, combined sets of signals of different polarizations can be combined. A receiver can include a single receive aperture.

Abstract: Interconnection systems and methods are provided. An interconnector as disclosed allows for a first component having a first coefficient of thermal expansion to be joined to a second component having a second coefficient of thermal expansion securely, and while maintaining a precise alignment between the components. The interconnector generally includes a plurality of pins that each have a free end that is adhered to the first component for imaging, sensing, tracking, processing, and other applications.

Abstract: A calibration system for sensors is provided. The calibration system includes an array of blackbody elements. Each blackbody element includes a high emissivity surface. The high emissivity surface can be formed using carbon nanotubes. In addition, each blackbody element includes a heating element and a temperature sensor. The heating element is operated to bring the blackbody element to a set point temperature, as determined by the temperature sensor. As an example, the calibration system can be used in connection with sensors sensitive to infrared wavelengths that is carried by a satellite or other platform.

Abstract: Lidar systems and methods are provided. The lidar system includes a laser that outputs light at two different wavelengths and an interferometer that is capable of generating fringe patterns for each of the two wavelengths simultaneously. More particularly, a first arm of the interferometer provides first and second path lengths. Light of a first of two or more wavelengths traverses the first path length within the first arm, while light of a second one of the two wavelengths traverses the second path length within the first arm. A second arm of the interferometer provides a third path length. Light from the first and second arms is then combined, and a phase shift of light of the first wavelength and a phase shift of light of the second wavelength are determined.

Abstract: Phased array antenna systems are disclosed. An antenna system as disclosed herein can include a plurality of antenna or radiating elements formed on a common plane comprising a first surface of a circuit board. Each antenna element has one or more feeds. Integrated circuits are placed on a second surface of the circuit board. Each integrated circuit is associated with one or more of the antenna elements. Signal lines connecting an integrated circuit to a feed of an antenna element can be shielded using interlayer ground planes and interlayer conductive plugs. In addition, back surfaces of the integrated circuits can be connected to a common heatsink using a thermally conductive medium.

Abstract: Methods and systems for locating a target radio frequency (RF) device within an area are provided. In particular, a signal sent from a known transmitter while that transmitter is at a known location is received by a plurality of receivers located in or around the area. This is repeated multiple times for multiple locations. Representations of the signals received at the receivers for the different locations are provided as inputs to a neural network and are used to train the network. After training, representations of signals received at the receivers as a result of one or more signals emitted from a target transmitter located in or traveling through the area can be provided to the network, which in response provides a location of the target transmitter.

Abstract: Antenna systems and methods providing dual polarization are provided. The system includes one or more antenna elements, with each antenna element having feed points on adjacent sides. A first of the feed points is associated with a first one of a transmitted or received signal, while a second one of the feed points is associated with a second one of a transmitted or received signal. The sides of the rectangular driven element can feature different lengths, to provide transmit and receive bands that are separated from one another in frequency. A polarizer is disposed between the antenna elements and free space. Linearly polarized signals from the antenna elements are transformed into circularly polarized signals by the polarizer. Circularly polarized signals received at the antenna system are transformed into linearly polarized signals before they are passed to the antenna elements. An antenna system as disclosed herein can include a plurality of antenna elements arranged in an array.

Abstract: Wide band adaptive beam forming methods and systems are provided. The beam forming methods can include receiving signals at multiple antenna elements and digitizing samples of the received signals for some period of time. The samples are divided into sub-channels according to frequency, and interferers are identified as signals appearing across at least some minimum number of the sub-channels. After removing signals not identified as interferers from the collected signal information, that information is used to calculate weights for forming a beam having a null at the identified location of the interferer. The beam forming systems include multiple element antennas having arms in the form of a spiral, and processing hardware for performing adaptive beam forming.

Abstract: Methods and systems for identifying occupied areas of a radio frequency (RF) spectrum, identifying areas within that RF spectrum that are unusable for further transmissions, and identifying areas within that RF spectrum that are occupied but that may nonetheless be available for additional RF transmissions are provided. Implementation of the method then systems can include the use of multiple deep neural networks (DNNs), such as convolutional neural networks (CNN's), that are provided with inputs in the form of RF spectrograms. Embodiments of the present disclosure can be applied to cognitive radios or other configurable communication devices, including but not limited to multiple inputs multiple output (MIMO) devices and 5G communication system devices.

Abstract: Free-space communication systems and methods are provided. The systems include a transmitter that combines multiple sets of radio-frequency-modulated optical carrier frequencies for transmission across free space using multiple transmission apertures. Different sets of signals are filtered to form single sideband signals. The different sets of single sideband signals are then combined to form dense wavelength division multiplexed signals. In addition, combined sets of signals of different polarizations can be combined. A receiver can include a single receive aperture.