Abstract: A drive unit (16) for an aircraft running gear (2) having at least a first wheel (4) and a second wheel (6) on a common wheel axis (A), wherein the drive unit (16) is drivingly coupleable to at least one of the first and second wheels (4, 6), is characterized in that the drive unit (16) comprises at least one power output assembly (122, 124) for driving at least one of the first and second wheels (4, 6), with each of the at least one power output assembly (122, 124) comprising a power transmission chain (136) selectively engageable with a sprocket element (108, 110) coupled to one of the first and second wheels (4, 6).

Abstract: A system for performing encryption and/or decryption may include a parent cryptographic device. The parent cryptographic device may be configured to receive a first cryptographic key. The parent cryptographic device may be configured to determine one or more session keys based on the first cryptographic key and/or internally generated random data bits. The parent cryptographic device may be configured to insert the one or more session keys onto one or more child cryptographic devices that are operably connected to the parent cryptographic device. The one or more child cryptographic devices may be configured to receive the one or more session keys from the parent cryptographic device, and perform one or more of encryption or decryption of communications exchanged with another child cryptographic device of the one or more child cryptographic devices. The one or more child cryptographic devices may perform encryption/decryption after separation from the parent cryptographic device.

Abstract: Disclosed herein are methods and systems for configuring and using one or more block ciphering techniques in order to encrypt/decrypt serial data streams while maintaining cryptographic synchronization and attempting to minimize the amount of overhead introduced into the stream. The techniques disclosed herein may be used to encrypt and decrypt serial data streams using a block cipher in a manner that can be substantially transparent to the devices involved in the serial communication session. For example, the serial user data may be left unframed by the encryption device while monitoring for opportunistic times to transmit framed cryptographic synchronization information during periods of relative inactivity in an asynchronous serial data stream. A cryptographic device implementing the techniques described herein may be configured to implement one or more of an encryption device or a decryption device.

Abstract: Electromagnetic (EM) feeds can illuminate a standard primary reflective antenna with a plurality of feed beams each having a different orbital angular momentum (OAM) or polarization. The reflective antenna, which can be a non-OAM antenna, can reflect the feed beams and thereby produce a composite OAM transmission comprising each of the feed beams. A non-OAM primary antenna can thus transmit a plurality of OAM feed beams as a composite OAM transmission.

Abstract: A method for receiving and removing co-channel interference from one or more received signals that comprise different symbol or chipping rates can comprise receiving a first composite signal and a second composite signal. The method can also comprise sampling the first composite signal and the second composite signal at a particular sampling rate that is sufficient to recover signal data from both the first composite signal and the second composite signal. Further, the method can comprise estimating from the second composite signal an estimated cross-coupled second signal within the first composite signal. The estimated cross-coupled second signal is estimated from at least the second composite signal at the particular sampling rate. Further still, the method can comprise recovering a substantially decoupled first data signal by removing at least a portion of the co-channel interference caused by the estimated cross-coupled second signal from the composite first signal.

Abstract: Systems and methods are provided that may implement independent and control-isolated audio processing (ICIAP) to separate and/or control audio streams at multiple levels of sensitivity and/or security. The disclosed systems and methods may be implemented in one example using separate real time digital audio processing and mixing hardware “channels” for each audio stream that are provided within an ICIAP connection system that includes at least one ICIAP audio processing device and a separate control processor, while at the same time incorporating a comprehensive set of interlocks to ensure the separation of audio data streams from one another and from control information, and to ensure authorization in real time for each different audio stream.

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: An interference cancellation system (ICS) may be used with a communication system to prevent or minimize interference from one or more sources. The ICS may receive radio RF signals comprised of one or more signals of interest (SOI) and multiple interfering signals. The ICS may use a sample of the interfering signals to cancel the interfering signals from the SOI. The multiple interfering signals may be converted into a single optical signal for cancellation. One or more optical cancellation paths may be used for interference cancellation. Each optical cancellation path may include an optical attenuator and/or an optical delay to achieve phase shifts and/or delays for interference cancellation.

Abstract: An interference cancellation system (ICS) may be used with a communication system to prevent or minimize interference from one or more sources. The ICS may receive radio frequency (RF) signals comprised of one or more signals of interest (SOI) and multiple interfering signals. An interference estimation processor (IEP) may be used to estimate the one or more interfering signals. The interfering signals may be estimated using spatial and/or time diversity, which may be combined with statistical methods. The estimated interfering signals may be sent to the ICS, which may use the estimated interference signal to cancel the interference and output the SOI.

Abstract: A DC/AC converter includes a DC/DC conversion stage with galvanic isolation and a DC/AC conversion stage, wherein the DC/DC conversion stage comprises a pair of first side terminals providing or receiving a first DC voltage, a pair of second side terminals providing or receiving a second DC voltage and coupled to the DC/AC conversion stage, at least one first side converter circuit coupled between the pair of first side terminals, a series connection of a plurality of second side converter circuits coupled between the pair of second side terminals, and at least one transformer circuit coupling the plurality of second side converter circuits to the at least one first side converter circuit, wherein a connection point between two of the plurality of second side converter circuits is coupled to the DC/AC conversion stage and forms a neutral phase point thereof.

Abstract: A data alignment method is provided by iteratively increasing the delay of each data input line of a system component until a test signal transmitted on each data input line is received at the system component at substantially a predetermined time.

Abstract: Adaptive filtering is used to substantially cancel distortion in radio frequency (RF) signals. Such adaptive filtering can be used in an RF transmitting module to pre-compensate an RF signal with compensation (inverse) distortion to cancel inherent transmission path distortion from the RF signal. Adaptive filtering can also be used in a multi-carrier RF receiving module to cancel from a given carrier signal distortion due to cross talk from adjacent carrier signals. Adaptive filtering in an RF transceiver can be used to cancel from a received RF signal distortion arising from leakage of a transmit signal into the receive path.

Abstract: A stepped-frequency radar signal is transmitted through a barrier. A transmitter of the stepped-frequency radar is on a first side of the barrier, a first object is on a second side of the barrier, and a second object that is distinct from the first object is on the second side of the barrier. A signal including a reflection of the transmitted signal from the first object and a reflection of the transmitted signal from the second object is sensed. The sensed signal is analyzed to determine that a first detection is associated with the first object and a second detection is associated with a second object.

Abstract: A circuit card can include a circulator for routing a signal from a first amplifier to an antenna and for routing a signal from the antenna to a second amplifier, replacing a traditional transfer switch. The circulator can be a surface mount element to enable the circulator, first amplifier, and second amplifier to be mounted on the same circuit card thereby minimizing the size of a transceiver that employs the circuit card. Multiple circulators can be included on the same circuit card to allow for multi-band operation.

Abstract: A horn-reflector antenna for tracking the location of in-flight aircraft is provided. The antenna includes an upwardly-opening horn having a reflector attached thereto. The horn may have an asymmetric rectangular cross-section and comprise at least one upwardly and outwardly extending side wall. The reflector includes a reflecting surface that may have a generally hyperbolic paraboloid shape or saddle shape. The horn and reflector may be constructed from a polymer material in an injection molding process. The reflecting surface of the reflector and the inner surfaces of the horn may be coated with a reflective or conductive material, for example, a paint comprising sliver-plated copper particles. In use, the horn-reflector antenna may be adapted to rotate around the longitudinal axis of a stationary waveguide feed. As such, the antenna of the present invention can be adapted for operation without the use of a rotary joint or a slip ring.

Abstract: A transponder system that is adapted to be positioned in an aircraft includes a transponder that is adapted to transmit information pertaining to the aircraft in which the transponder is positioned includes at least one receiver that is adapted to receive information including information pertaining to another aircraft. The receiver(s) is adapted to receive different types of data on multiple different frequencies. A display, which may be integral with the system housing or remotely mounted, is adapted to display (i) information received by said receiver and/or (ii) information to guide user input selection of information transmitted by said transponder. The housing houses the transponder, the receiver and, in one embodiment, the display. The existing transponder in the aircraft can be removed thereby leaving an opening in the aircraft and the transponder installed in the opening.

Abstract: Panoramic imaging systems and methods for manufacturing and arranging the same are disclosed. A panoramic imaging system includes a mounting frame, an image sensor coupled to the mounting frame, and an optical de-rotation device arranged in an optical path of the image sensor. The optical de-rotation device and the image sensor are oriented such that the optical de-rotation device and the image sensor are in the same plane. The optical de-rotation device removes motion-related blur that would be observed by the image sensor when a rotational movement external to the panoramic imaging system causes the panoramic imaging system to rotate.

Abstract: The angular position of an output gear can be determined from the phase difference between the angular positions of pinions engaged with the output gear. The first pinion can have a K-number of teeth, the second pinion can have an L-number of teeth, and the output gear can have an M-number of teeth. The relationship between K, L, and M can include the following: M is the least common multiple of K and L; and the absolute value of the difference between M divided by K and M divided by L is one. It can also be said that the absolute value of L subtracted from K is a non-zero integer.

Abstract: Panoramic imaging systems including rotatable mirrors are provided. A panoramic imaging system includes a rotatable platform, an imaging device mounted to the rotatable platform, and a mirror rotatably mounted to the rotatable platform. The mirror is positioned in an optical path of the imaging device. The mirror and the imaging device are oriented such that the mirror and imaging device are in the same plane, an optical axis of the imaging device is substantially perpendicular to an axis of rotation of the rotatable platform, and an axis of rotation of the mirror is substantially parallel to the axis of rotation of the rotatable platform when the mirror is in an initial position.

Abstract: An Automatic Dependent Surveillance-Broadcast (ADS-B) system, and method of harmonizing a transponder Squawk code and an ADS-B system, ensures that a Squawk code broadcast by the ADS-B system matches the transponder Squawk code. The transponder Squawk code is transmitted from a transponder positioned onboard an aircraft and the transmitted transponder Squawk code with a device positioned onboard the aircraft. A Squawk code input of an ADS-B Squawk code to be transmitted with the ADS-B system is received. The ADS-B Squawk code is compared with the received transmitter Squawk code using a comparator and the pilot is informed whether the transmitter Squawk code matches the ADS-B Squawk code. A message formatter generates a message that includes the ADS-B Squawk code. A wireless transmitter broadcasts the ADS-B Squawk code generated by the message formatter.