Abstract: A center region of conductive material/s may be disposed or “sandwiched” between transition regions of relatively lower conductivity materials to provide substantially low defect density interfaces for the sandwiched material. The center region and surrounding transition regions may in turn be disposed or sandwiched between dielectric insulative material to form a sandwiched and transitioned device structure. The center region of such a sandwiched structure may be implemented, for example, as a device layer such as conductive microbolometer layer for a microbolometer detector structure.

Abstract: A first device and a second device can include at least one alignment feature and at least one corresponding constraint. The alignment feature and the constraint can be configured to align the first device and the second device when the alignment feature is inserted into the constraint. The alignment feature and the constraint can be further configured to direct relative movement between the first device and the second device due to relative thermal expansion or contraction between the first device and the second device. The directed relative movement can keep the first device and the second device aligned over a predetermined temperature range.

Abstract: The present invention is directed to a decision feedback equalizer that implements a multipath delay calculator to determine the delay between a line-of-sight component of a received data signal and a reflection of the line-of-sight component. The determined delay is used to control when decisions are used within the decision feedback equalizer so that the appropriate decisions are delayed until the reflection is received. In this way, the reflection can be substantially removed from the data signal using decisions that were generated when the line-of-sight component was received. Because the correction window is limited to the time when the reflection is received, the number of taps required to perform equalization is greatly reduced resulting in a decision feedback equalizer with less circuitry or logic.

Abstract: A technique for performing parallel-input parallel-output infinite impulse response (IIR) filtering uses two parallel-input-parallel-output finite impulse response (FIR) filters. One FIR filter is used as a feed-forward filter and one FIR filter is used as a feed-back filter. The feed-back filter is coupled to delays and summers to allow the filter operations to be performed in parallel.

Abstract: An interference channel equalizer for receiving and processing at least two distinct RF data signals transmitted over the same frequency to a single receiving station that has at least one receiver for each distinct transmitted RF data signal. Each receiver processes an RF data signal received by its antenna and outputs an output data signal which corresponds to one of the distinct transmitted RF data signals. Each receiver includes an antenna configured to receive an RF data signal, a demodulator, a delay block to selectively delay the received RF data signal, an interference cancellation feed forward filter that uses the received signal from another receiver to remove co-channel due to another distinct RF transmitted data signal from the signal being processed, and a decision feedback equalizer to mitigate both intersymbol and multi-path interference from the received signal being processed.

Abstract: Wireless terminals, systems, and methods use interlaced diplexers. A first diplexer can provide a first pair of bands separated by a first separation band, and a second diplexer can provide a second pair of bands separated by a second separation band. The first separation band and the second separation band can overlap. Transceivers (comprising transmitters and receivers) can be coupled to the diplexers to provide frequency-division duplex communications using one or both of the pairs of bands.

Abstract: In one exemplary embodiment, an antenna arrangement includes: a substrate; and a plurality of dipole antenna elements disposed on the substrate, wherein the plurality of dipole antenna elements are randomly-oriented with respect to each other. In further exemplary embodiments, the plurality of dipole antenna elements includes at least six dipoles that are all electrically fed and do not need to be magnetically fed in order to generate and detect an arbitrary polarization. In still further exemplary embodiments, each dipole element has a fractal shape.

Abstract: Synchronization of a primary link which transitions between clear mode and spread mode is achieved and maintained using a secondary link. When transitioning from clear mode to spread mode, a primary transmission delta phase is adjusted by the difference between a secondary reception delta phase and the primary transmission delta phase; and a primary reception delta phase is adjusted to be equal to a secondary transmission delta phase.

Abstract: Techniques for modulation and demodulation using near-Nyquist sampling operate using substantially band-limited signal. In modulating, the substantially band-limited signal is formed by filtering modulated symbol date to produce a complex sample stream having a bandwidth of less than the twice the associated symbol transmission rate and with a sample rate of less than twice the symbol rate. In demodulating, a substantially band-limited signal having a bandwidth of less than twice the associated symbol transmission rate is sampled at a sample rate of less than twice the symbol rate of the modulation.

Abstract: In one exemplary embodiment of the invention, a device includes: a first frequency search engine configured to receive input values and determine a frequency of a signal to be within a first frequency band; a second delay component configured to store at least a portion of the plurality of input values; and a second frequency search engine configured to determine the frequency of the signal to be within a second band that is a subset of the first band. The first frequency search engine includes: a shift register configured to store bits of the input values; a combining circuit configured to combine bits of the plurality of input values; a first delay component configured to serially store a plurality of accumulator values; and a feedback circuit configured to add a function of the first delay component output to a next accumulator value to obtain a modified next accumulator value.

Abstract: Systems and methods for improving the reliability of a hub-spoke communications system use a first antenna and a second antenna at the hub terminal. Spread spectrum transmission from the hub terminal uses the first antenna, and the second antenna is enabled when blockage between the first antenna and any one of the spoke terminals is present. The first antenna and the second antenna have substantially orthogonal polarizations. The spread spectrum transmissions from the first antenna and second antenna have different pseudonoise code timing so that the received transmissions are offset by at least one chip interval from each other.

Abstract: A technique for reducing memory usage during signal processing includes storing least significant portions of a plurality of intermediate results in a first memory. Most significant portions of a subset the plurality of intermediate results are stored in a second memory having a smaller length than the first memory. A data linkage is maintained between the most significant portions and corresponding least significant portions.

Abstract: Transmitter-directed transmission security is provided between a transmit node and a receive node. The transmit node selects transmission format for each data frame based on a transmission security scenario. Information related to the transmission format is communicated between the transmit node and the receive node, and the data frames are transmitted over a wireless communication link using the selected transmission formats.

Abstract: Techniques for efficient upconversion can process complex input data, such as for example data in an inphase and quadrature form. Half sample interpolation filtering and delay can be performed, and the results can be combined in a quarter-rate upconverter. The quarter rate upconversion can allow one of the half-sample interpolating filtering and the delay to be performed on one of either the inphase and quadrature samples.

Abstract: Methods and terminals can use Internet Protocol (IP) packets for waveform independent contention access in a hub-spoke network. In some embodiments, a spoke terminal can transmit a link allocation packet on an uplink when the uplink is available and the spoke terminal has data to transmit. The link allocation packet can be embedded within an IP packet. When the spoke terminal receives the link allocation packet on the downlink, the spoke terminal can transmit one or more IP packets with data, followed by a link release packet. The link release packet can be embedded within an IP packet.

Abstract: A technique for decoding low-density parity check codes includes performing a combined check node and variable node calculation. Decoding is initialized using channel likelihood values estimated from a received physical signal. The decoding iteratively updates the variable nodes. Performing a combined check node and variable node calculation can enable reduced memory usage and faster convergence for the decoder.

Abstract: A directional access network can include a plurality of nodes and wireless links between ones of the nodes. Topology management of the network can discover when network fragmentation exists, identify nodes positioned to heal the fragmentation, and establish new active links between the identified nodes.

Abstract: An emergency locating system can include emergency transceivers and locator transceivers. The emergency transceivers can be capable of transmission of spread-spectrum encoded messages, and can be actuated by a user to send a distress message. A locator transceiver can be capable of receiving the distress messages and performing two-way ranging to determine a distance between the locator transceiver and the emergency transceiver.

Abstract: A transportable directional antenna system includes an antenna pedestal, a plurality of outriggers, and an earth anchor. The earth anchor can be coupled to a horizontally centered point on the pedestal. Tension can be applied between the earth anchor and the pedestal to substantially preload the outriggers and the surface on which they bear to provide a highly stable antenna.

Abstract: Decreased capability for detection of communications signals by an adversary is provided by applying frequency hopping, frequency chirping, and direct sequence spreading to the signals. The frequency hopping and frequency chirping can be driven by pseudo random functions. The direct sequence spreading can use a pseudo random chip sequence.