Abstract: Techniques are provided for decorrelation of intermodulation products in mixer circuits. A circuit implementing the techniques according to an embodiment includes four switches. Each of the switches comprise a complementary pair of n-channel and p-channel metal oxide semiconductor (NMOS/PMOS) field effect transistors (FETs). The NMOS/PMOS FETs include a source port, a drain port, and a gate port. The gate port is configured to receive an oscillator signal. The circuit also includes electrical conductors to couple the four switches into a double-balanced passive ring configuration to generate an output signal as a mix of an input signal and the oscillator signal. The output signal includes a third order intermodulation (IM3) product. The circuit further includes a voltage bias generator to generate a bias voltage to bias the input signal and the output signal. The magnitude and phase of the IM3 product are determined, at least in part, by the bias voltage.

Abstract: Techniques, systems, architectures, and methods for estimating the rise time of a pulse for multi-channel and signal channel cases involving an optimization system and method that can be solved iteratively based on sparse priors for a wide span of signal-to-noise ratios.

Abstract: Techniques are disclosed for generating a featureless low-probability-of-intercept/low-probability-of-detection (LPI/LPD) waveform via a continuously variable symbol rate transmission. A continuous-phase-modulation (CPM) signal can be represented with a phase trellis. During each symbol duration, the trellis is traversed in either a positive or negative direction in a continuous fashion from the starting phase value to the end phase value. The rate at which the trellis is traversed is varied continuously as a time-varying function. The time-varying phase velocity function, or instantaneous symbol rate, is a type of spreading code or secret key shared between the transmitter and receiver. The disclosed techniques can be implemented with CPM compromising the constant-modulus property of CPM signals.

Abstract: Disclosed is an anti-vibration apparatus comprising a bush, said bush comprising a substantially rigid, elongate core, covered in a vibration dampening material having at least one end cap washer, configured in that the bush engages with the end cap washer to cover the end of the elongate core, characterised in that the vibration dampening material further comprises a plurality of recessed portions on its surface.

Abstract: A port is provided that utilized various techniques to manage contention for the same by controlling data that is written to and read from the port in multi-core assembly within a usable computing system. When the port is a sampling port, the assembly may include at least two cores, a plurality of buffers in operative communication with the at least one sampling ports, a non-blocking contention management unit comprising a plurality of pointers that collectively operate to manage contention of shared ports in a multi-core computing system. When the port is queuing port, the assembly may include buffers in communication with the queuing port and the buffers are configured to hold multiple messages in the queuing port. The assembly may manage contention of shared queuing ports in a multi-core computing system.

Abstract: Methods and structures are disclosed for self-automating a process of determining a device's location based on its network address. A computing device includes a network interface configured to communicate with a physical port of a network switch and a memory configured to store a plurality of different initialization protocols each associated with a corresponding network address of a plurality of network addresses. Each of the initialization protocols may be associated with a different physical location. The computing device also includes a processor configured to attempt to connect to the network switch via the network interface using a network address from the stored plurality of network addresses. In response to connecting with the network switch using the network address, the processor identifies a corresponding initialization protocol associated with the network address and executes the corresponding initialized procedure.

Abstract: Underwater navigational systems and methods utilizing sunlight polarized via scattering through the water column that does not require an underwater vehicle to surface or use a global position system to maintain precise navigational positions and headings. These navigational systems and methods may be employed by manned or unmanned underwater vehicles and may be utilized by individual units and by units operating in a swarm.

Abstract: Methods and structures are disclosed for providing autonomous control of an underwater vehicle using a state machine. A controller is used onboard the underwater vehicle and includes a state machine having a plurality of operating states. Each of the plurality of operating states includes one or both of entrance criteria and exit criteria. The controller is configured to transition from executing a first operating state of the plurality of operating states to executing a second operating state of the plurality of operating states in response to the exit criteria of the first operating state and the entrance criteria of the second operating state both being met. The plurality of operating states includes a first portion of operating states associated with a first task, a second portion of operating states associated with a second task, and a third portion of operating states associated with both the first and second tasks.

Abstract: Techniques are provided for non-volatile detection of an overvoltage condition in a circuit of interest. A circuit implementing the techniques according to an embodiment includes a fuse configured to provide a non-volatile indication of an overvoltage event, the indication associated with an open state of the fuse. The circuit also includes a voltage controlled current switch coupled in series to the fuse. The voltage controlled current switch is configured to enable current flow through the fuse in response to a supply voltage exceeding a threshold value associated with the overvoltage event. The current causes the fuse to switch from a closed state to an open state providing a non-volatile record of the overvoltage event. In some embodiments, the voltage controlled current switch can be a Zener diode with a breakdown voltage based on the threshold value, or a transistor configured to switch into conducting mode at the threshold value.

Abstract: Apparatus (100) for use in space, the apparatus (100) comprising: a feedstock storage module (108) for storing a feedstock; a heating module (110) coupled to the feedstock storage module (108) and configured to heat the feedstock; an extrusion nozzle (112) coupled to the heating module (110) and configured to extrude heated feedstock from the apparatus (110); and one or more thrusters (118) configured to provide a propulsive force to the apparatus (100).

Abstract: The invention comprises of a UAV designed to limit visually contrast and audibility in flight for covert surveillance operations, a method of configuring the UAVs structure to further reduce its visual signature to take account for the atmospheric and terrestrial environment it will operate in and a method of conducting a covert surveillance operation to actively minimise the UAVs visual & auditory signature from the viewpoint of an individual under surveillance. Both passive and active illumination are used to reduce the visual signature of the UAV. The UAV is actively camouflaged using lighting techniques that utilises the limitations of the human visual system and the optical effects of light interacting with the terrain, atmosphere and aircraft. The visual camouflage is directional. The audible signature of the UAV is reduced through the design of the propulsion system and the mode in which the UAV is operated.

Abstract: An assembly comprising a horizontal GPS patch antenna element and a vertical IFF antenna element providing simultaneous high performance IFF communication and GPS reception with minimal IFF to GPS interference. The IFF element can be a monopole element. A second monopole co-linear with the IFF element can provide simultaneous UHF communication. In embodiments, the assembly is a blade that can replace an existing IFF blade on an aircraft or other asset. Separate IFF and GPS connectors can be provided, or a single connecter can be shared using an integral diplexer. Embodiments include a GPS preamplifier integral with the blade. In other embodiments, the IFF element is an annular slot transponder that is centered on the GPS patch element. System embodiments include bandpass filters and/or GPS blanking to further protect the GPS receiver from IFF transmissions.

Abstract: A radio frequency (RF) filter includes a signal conditioning circuit and a bandstop filter. The signal conditioning circuit receives a broadband RF signal that includes both a jamming signal at a jamming frequency and a signal of interest and generates a plurality of clock signals. Each of the plurality of clock signals has a substantially same frequency as the jamming frequency, but a different phase shift. The bandstop filter receives the RF signal and the plurality of clock signals. The bandstop filter attenuates signals within a bandstop centered at the frequency of the plurality of clock signals. A self-tuning N-path filter is provided.

Abstract: An inflatable mast couplable to an underwater vehicle includes a flexible material defining an interior volume, a head structure, and a spring coupled to at least one of the flexible material and the head structure. The flexible material is designed to be filled with air to form an inflated mast structure that extends away from the underwater vehicle. The head structure is disposed at a distal end of the inflated mast structure and in some cases has a rigid shape that forms a panel having an outer surface that is flush with an outer surface of the underwater vehicle, when the mast structure is deflated and stowed. The spring is designed to provide a tensile force on at least one of the flexible material and the head structure when the flexible material is inflated to form the mast structure. A system includes the inflatable mast and a pump.

Abstract: Techniques are disclosed for determining AOA of one or more radar pulses received at a vehicle and originating from a source. The techniques are particularly well-suited to provide pilots with a more accurate determination of the azimuth angle to the radar source, although ground-based and water-based vehicles may benefit as well. Some embodiments discussed herein determine a true estimation of both azimuth and elevation angles, with reference to an aircraft's body-centered coordinate system, to the radar source. These parameters can also be used to determine a more accurate position on the ground for the radar source.

Abstract: A method for modifying a portion of a substrate after production is described herein. The method can include diagnosing a circuit operation error causing a malfunction, identifying a first contact on the substrate, and connecting, electrically, the first contact to a second contact with at least one trace. The trace is done with a focused ion beam. The method can include diagnosing an error on an operative area of a post-manufacture circuit board causing a malfunction; introducing a metal precursor into a focused ion beam chamber; ionizing the metal precursor by contacting it with a gallium ion beam into a conductive metal and a further ion; depositing a first portion of a conductive metal onto a substrate to form a first trace; and forming the first trace between the operative area and a non-operative area thereby connecting the operative area and the non-operative area.

Abstract: A combined spatial and time multiplexer device is disclosed. The device organizes and selects any signal(s), including past data, from amongst a plurality of time division multiplexed (TDM) data streams. The data streams are collected by memory devices that are configured to separately store the multiplexed signals such that different time portions of the signals from each data stream are stored in different addressable sections. This allows for the current time data and past time data for a given signal to be selected and outputted by the device. According to an embodiment, each of the memory devices receives an address select signal and selects a signal group based on the address select signal. The device also includes a multiplexer that selects one of the signal groups from amongst the memory devices to output as the requested signal group.

Abstract: A battery cell module includes a housing having a stack of a plurality of battery cells. The stack includes a plurality of battery cells sequentially stacked within the housing. Each of the battery cells has first and second opposed faces. The stack further includes a plurality of heat sink plates sequentially interleaved between the plurality of battery cells. Each of the plurality of heat sink plates has a body extending in a first plane surrounded by an outer edge. The body has a plurality of mounting tabs arranged to support a respective battery cell in the sequential stack within the housing such that the plurality of battery cells are maintained in alignment within the housing. A method includes sequentially interleaving battery cells and heat sink plates within a housing, where mounting tabs in the heart sink plates maintain the battery cells in alignment within the housing.

Abstract: The present disclosure provides a system and method for determining a range to an object in a fluid. The system includes a polarized light source directed to the object in the fluid, a first imaging sensor, a second imaging sensor, and at least one processor. The at least one processor characterizes a depolarization rate of the fluid and determines the range to the object. The method includes generating polarized light via a polarized light source, polarizing an imager relative to the polarized light, transmitting the polarized light from the polarized light source into the fluid, receiving reflected light from the object, characterizing a depolarization rate of the fluid, based, at least in part, on the reflected light, and determining the range to the object, based, at least in part, on the depolarization rate of the fluid.

Abstract: A self-localizing autonomous underwater vehicle swarm that is operable to accurately localize each individual unit within the swarm while only requiring a single node at a known location to do so. The methods described herein can localize all members of a swarm with minimal, if any, effect on the size, weight, power, and cost of a system.