Abstract: A signal coupler can couple a processed version of an outgoing signal from a transmission path to a receive path in a transceiver. A connector can provide the processed version of the outgoing signal to a pre-distortion module, which can generate a pre-distortion signal to pre-compensate outgoing signals in the transmission path of the transceiver. A receive path of a transceiver can thus be utilized as a feedback path to a pre-distortion module.

Abstract: A phase shifting component of a waveguide comparator subsystem can effect a relative phase shift that advances an input signal A relative to an input signal B. A comparator component can then split those signals such that a first part of signal A and a second part of signal B are combined at a difference port, and a first part of signal B and a second part of signal A are combined at a sum port. The comparator can delay the phase of the second parts of the signals such that, with the relative phase shift of the phase shifting component, the first part of signal A and the second part of signal B are one-hundred eighty degrees (180°) out of phase at the difference port, and the second part of signal A and the first part of signal B are in phase at the sum port.

Abstract: Night vision devices utilize image intensifier tubes to see in low light conditions. A man-portable tester allows an operator to check for defects and determine the image resolution of the image intensifier tube quickly and easily without a power source or a darkened room.

Abstract: A decoder for decoding received vectors r encoded in accordance with a forward error correction code having a parity check matrix H with multiple regions at least two of which have patterns of ones with different pattern characteristics. The decoder can include a permuted decode module configured to decode in accordance with a permuted version of the parity check matrix H in which the ones in one of the regions are permuted into a permuted pattern that has a pattern characteristic of the other region. The decoder can also include a reorder module that permutes probabilities of a received vector r to be decoded to correspond with the permuted parity check matrix H.

Abstract: An imaging system exposes an object within a region to a beam of penetrating radiation. The beam of penetrating radiation is sensed on a side opposite the region from a source of the beam. An attenuation of the beam caused by passing the beam through the object is determined, the attenuation is compared to a threshold attenuation. If the attenuation exceeds the threshold attenuation, a parameter of the imaging system is adjusted based on the determined attenuation.

Abstract: A multi-mode parameter adaptation module can comprise different modes for generating parameters to minimize an error between an output of an adaptive processor and an ideal output of the adaptive processor. A mode control module can monitor a performance signal p indicative of an operating condition a receiver of which the adaptive processor is a part. Upon detecting a change condition form the performance signal p, the mode control module can change the operating mode of the parameter adaptation module to suit the current operating condition.

Abstract: Methods and systems are disclosed for testing and/or validating that an untrusted device is operating according to an expected state or configuration. The methods and systems may be designed such that the volatile memory of the untrusted device is brought to a known state for validation, for example upon ingress to or egress from a protected mode of operation. The device may execute a first operating system when operating outside of the protected mode. Upon determining to transition to protected mode, an operational image of a second operating system may be loaded into the device. The device may write a pattern to unused memory for validation. The device may receive a first challenge request from a trusted monitor (TM). In order to be successfully validated, the device may answer the challenge correctly within a given response window based on the current state of its volatile memory.

Abstract: Methods, systems, and apparatuses, including computer programs encoded on a computer storage medium, for generating location and size measurements for small scattered objects in a large medium are disclosed.

Abstract: Radiation is directed at an object, and radiation scattered by the object is sensed. An angular distribution of scatter in the sensed scattered radiation relative to a path of the radiation directed at the object is determined, and the angular distribution is evaluated. One or more atomic numbers, or effective atomic numbers, of materials composing the object is determined based on evaluating the angular distribution.

Abstract: Methods, apparatus, and computer readable storage medium for authenticating assertions of a source are disclosed. In one aspect, a method for authenticating an assertion of a source in an environment of distributed control include receiving a notification of the assertion; determining an entity responsible for maintaining an authenticated list of assertions by the source based on a first trusted public record, determining an assertion authenticator for the entity based on a second trusted public record, determining one or more assertions of the source from the assertion authenticator, and authenticating the assertion based on the determined one or more assertions.

Abstract: Frontside-illuminated barrier infrared photodetector devices and methods of fabrication are disclosed. In one embodiment, a frontside-illuminated barrier infrared photodetector includes a transparent carrier substrate, and a plurality of pixels. Each pixel of the plurality of pixels includes an absorber layer, a barrier layer on the absorber layer, a collector layer on the barrier layer, and a backside electrical contact coupled to the absorber layer. Each pixel has a frontside and a backside. The absorber layer and the barrier layer are non-continuous across the plurality of pixels, and the barrier layer of each pixel is closer to a scene than the absorber layer of each pixel. A plurality of frontside common electrical contacts is coupled to the frontside of the plurality of pixels, wherein the frontside of the plurality of pixels and the plurality of frontside common electrical contacts are bonded to the transparent carrier substrate.

Abstract: A system and method for imaging objects with a sparse detector array that includes fewer detectors than conventional x-ray scanning systems. The sparse detector array is positioned to receive x-ray radiation from the at least one x-ray source after passing through an inspection area. The sparse detector array includes a plurality of rows of detector elements, wherein at least some of the plurality of rows are separated by gaps such that the at least some of the plurality of rows are non-contiguous. An iterative reconstruction process is used to determine a volumetric image of the object from the radiation measurements recorded by the detectors in the sparse detector array.

Abstract: A system and method for enabling transmission of a stepped-frequency radar signal can involve a first antenna and a second antenna. The system can also involve receiving circuitry configured to receive detected reflections from the antennas and to generate data including information associated with frequency and phase shifts. The system can further involve a processor configured to receive the generated data from the receiving circuitry and to analyze the generated data to determine information associated with a moving object located at a side of a wall opposite to the system by differentiating reflections of the transmitted signal detected with the first antenna from reflections of the transmitted signal detected with the second antenna.

Abstract: An imaging system exposes an object within a region to a beam of penetrating radiation. The beam of penetrating radiation is sensed on a side opposite the region from a source of the beam. An attenuation of the beam caused by passing the beam through the object is determined, the attenuation is compared to a threshold attenuation. If the attenuation exceeds the threshold attenuation, a parameter of the imaging system is adjusted based on the determined attenuation.

Abstract: A transmit antenna or antennas can be configured to transmit a composite orbital angular momentum (OAM) radio frequency (RF) beam comprising a plurality of individual OAM RF signals each having a different OAM mode. An array of antennas for receiving and resolving the composite OAM beam into the individual OAM signals can be located entirely within a relatively small sector of a far field pattern of the composite OAM beam. A processing module connected to the antennas of the receive array can resolve the composite OAM beam into its individual OAM signals using angular resolution. The transmit antenna can transmit the individual OAM signals—and thus the composite OAM beam—as full OAM signals or partial-beam OAM signals.

Abstract: A cluster of communications platforms can comprise a master platform and support platforms. The master platform can partition a data block into data partitions and transmit the data partitions via a short range transmitter to the support platforms. Each support platform can include a high power storage device for powering long range burst transmissions of a subset of the data partitions to a distant receiver. Burst transmissions of data partitions by the same support platform can be separated by a charging time period that allows a high power storage device in the support platform to charge from a relatively low average power Pa a relatively high power burst PB that is sufficient to transmit one of the data partitions to a distant receiver.

Abstract: A handheld communications device is created with a touch sensitive display, a secure computing component, and a non-secure computing component. The secure component may comprise a secure CPU executing a secure operating system. The non-secure component may comprise a separate non-secure CPU executing a separate non-secure operating system. The touch sensitive display on the handheld communications device is divided into a secure portion and a non-secure portion such that information displayed in the secure portion is provided by the secure operating system, and information displayed in the non-secure portion is provided by the non-secure operating system. Similarly, data entered through the secure portion of the display is provided to the secure operating system, and data entered through the non-secure portion of the display is provided to the non-secure operating system.

Abstract: A radio signal transmission technique includes selecting a sample rate from a plurality of predefined sample rates so that the radio signal is contained entirely within a Nyquist zone corresponding to the sample rate. A digitized signal is converted to an analog signal, spectrally enhanced, and passed through a selected one of a plurality of selectable bandpass filters to form the radio signal.

Abstract: The perceived sample rate at which a DAC can operate can be increased by allowing multiple DACs to process different portions of a digital signal in parallel. In this way, the outputs of multiple DACs can be combined into a single analog signal to achieve the desired speeds and resolutions of the analog output. This parallel processing can be implemented using a time-interleaving technique or a sub-band reconstruction technique. Pre-distortion can be applied to the digital input signal to compensate for degradation detected in the analog output signal. By applying pre-distortion, waveforms having high sampling rates can be efficiently generated.

Abstract: A drive unit for an aircraft ground wheel associated with a brake unit for braking the ground wheel includes: a driving motor drivingly coupleable to the ground wheel; and a cooling system including at least a drive cooling unit configured to generate a drive cooling air stream for cooling the drive unit and a brake cooling unit configured to generate a brake cooling air stream by sucking in air from the brake unit. A method of controlling such drive unit in which the cooling system is driven by the driving motor of the drive unit includes: decoupling the driving motor from the ground wheel and increasing the rotational speed of the driving motor to increase the amount of generated drive cooling air, when an operating condition of the ground wheel and/or of the drive unit is switched from a propulsion mode to a non-propulsion mode.