Abstract: A computation efficient polyphase channelization system enables one of many user FDMA signals to be channelized through multiple FFT response frequency bands forming an aggregate frequency band where K-point FFT channels are greater than the decimation factor M to produce FFT overlapped responses that have a smooth aggregate response without disjointed band gaps for reduced distortion using a clockwise commutator having M channels feeding M filter blocks, each of which having ? polyphase filters, and having a ring switch to provide smooth filter responses that then drive ? K-point FFTs to provide a ? set of K vector FFT responses that are then combined in a post processing system for producing K channelized outputs.

Abstract: A direct sequence spread spectrum receiver includes a first spreading code generator for receiving a first channel signal spectrum spread by a first spread code, while a second group of receivers use a second spreading code, where the first and second codes are partially correlated, so that, the first group of receivers receive all messages communicated while the second group of receivers only receives a portion of the messages. In this manner, a spread spectrum broadcast system can selectively communicate to a selected portion of receivers in a whole group of receivers by simply switching the spreading code at the transmitter.

Abstract: An acoustical mechanical test method prescribes compressing brittle balls in spherical conforming opposing platens producing equatorial bulging, tensile stresses, and resulting in crack or flaw growth with emissions of acoustical sounds for direct identification of brittle balls having a flaw exceeding a maximum allowable size, such as flaws in silicon-nitride balls used in hybrid bearings as well as conventional steel ball bearings.

Abstract: A power controller in a communication system adjusts the transmitted power level using adaptive prediction of channel fading for maintaining the power level for improved communications by using an adaptive nonlinear predictor that explicitly takes into account the propagation delay and channel fading where the transmitted power is determined on the basis of the measurement of the received power levels over the individual diversity branches for providing communication through a fading channel with effective performance equivalent to that of a channel without any signal fading.

Abstract: A multithreaded processor is programmed for executing multiple simultaneous working programs by respective processor worker threads each executing the identical code having identical results for achieving redundant operations that can be compared to each other by one or more checker threads for determining when one of the working programs or checker threads has failed for a single event fault detection and recovery of a failed worker or checker monitoring program so as to mitigate the effects of single event failure that may be due to radiation.

Abstract: A communications system reduces downconverter inaccuracies in time-domain measurements or samples of received microwave communications I and Q complex signals by converting received signal to baseband taking measurements or samples of the I and Q waveforms at differing phase shifts of a demodulating carrier signal for a local oscillator or carrier tracking loop used during downconversion so that I and Q imbalances may be detected and removed by lowpass equivalent averaging for improved characterization of downconverters or for improved signal reception. In the preferred form, the phase shifts are 0 and ?/2 for a conventional measurement, and then at ?, and ?+?/2, with ?=?/4+m?/2 for an integer m for the second measurement where I and Q imbalances and baseband nonlinearities are indicated by differences between the two measured or sampled signals, where ? provides for optimum error detection for reducing the errors by averaging the measurements.

Abstract: A laser beam detection and tracking system includes a focal plane array sensor providing pixel data and a field programmable gate array controller receiving the pixel data for determining a centroid of the illuminating spot of the impinging laser beam and for determining variably sized windows of interest disposed around the spot for selecting a subset of pixels of the array for communicating a subset of the pixel of a window frame of data from the array to the controller for increasing the array frame rate for reducing laser jitter during tracking of the beam for improved beam tracking performance.

Abstract: A parallel orthogonal frequency division multiplexed (OFDM) communications system includes a transmitter and receiver, the transmitter having a parallel fast Fourier transform (FFT) module operating in parallel to a conventional inverse fast Fourier transform (IFFT) module for providing respective orthogonal outputs received by the receiver. The receiver has a parallel IFFT module and a conventional FFT module for providing respective orthogonal outputs. The respective orthogonal outputs are combined to form a composite signal that provides improved insensitivity to relative frequency offsets and Doppler frequency offsets. The parallel FFT and IFFT modules in the OFDM communication system provides improved signal diversity and performance in the presence of relative frequency offsets and Doppler frequency offsets, and provides improved tracking capability for the receiver with backward compatibility.

Abstract: A thin film solar cell thermal radiator configuration uses an embedded power bus to collect vertically migrating waste heat from electronic devices mounted on a thin film multilayer printed circuit board. The waste heat is vertically collected, horizontally spread, and vertically rejected through the a top coverglass glass layer around the side of a top silver contact of conventional thin film solar cells. The thermal radiator configuration enables the collection and rejection of the electronic component waste heat for maintaining thin film solar cells within desired temperature ranges.

Abstract: An intermodulation product reduction or cancellation amplifier received two input signals that are split in quadrature wherein the inphase outputs are summed and then amplified as an inphase signal, and the quadrature outputs are fixed-phase phase-shifted, then summed and then amplified as a quadrature signal. The inphase and quadrature signals are fed into an output hybrid for canceling intermodulation products, where the fixed-phase phase shift is +/?60° for reducing 3rd order, +/?36° for reducing 5th order, and +/?25.71° for reducing 7th order intermodulation products, for examples, for improved signal communications of the two signals over a common antenna or link.

Abstract: Reactive halogen-ion plasmas, having for example, generating chloride ions, generated from low-pressure halogen gases using a radio-frequency plasma are employed for producing low-friction carbon coatings, such as a pure carbon film, at or near room temperature on a bulk or thin film of a compound, such as titanium carbide.

Abstract: Polymer nanofibers, such as polyaniline nanofibers, with uniform diameters less than 500 nm can be made in bulk quantities through a facile aqueous and organic interfacial polymerization method at ambient conditions. The nanofibers have lengths varying from 500 nm to 10 ?m and form interconnected networks in a thin film. Thin film nanofiber sensors can be made of the polyaniline nanofibers having superior performance in both sensitivity and time response to a variety of gas vapors including, acids, bases, redox active vapors, alcohols and volatile organic chemicals.

Abstract: Platinum (Pt) thin film heaters are deposited by a focused ion beam for semiconductor manufacturing of thermally tunable distributed feedback lasers. An exemplar 1.3 ?m InGaAsP/InP laser is integrated with a tuning element having a wide wavelength tuning range of 4.9 nm, that is, 857 GHz, with a small heater current of 13.0 mA.

Abstract: An improved radiation dosimeter device in an improved radiation dosimeter system provides a DC analog output voltage that is proportional to the total ionizing dose accumulated as a function of time at the location of the dosimeter in a host spacecraft, so as to operate in a system bus voltage range common to spacecraft systems with the output being compatible with conventional spacecraft analog inputs, while the total dose is measured precisely by continually monitoring the energy deposited in a silicon test mass accumulating charge including charge contribution prior to radiation threshold detection for improved measurement of the total accumulated charge with the dosimeters being daisy-chained and distributed about the spacecraft for providing a spacecraft dose profile about the spacecraft using the improved radiation dosimeter system.

Abstract: An RF-discharge lamp stabilization system for preferred use in a Rubidium atomic clock, senses acoustic oscillations of plasma ions in the 20.0 kHz range to assess the performance of the lamp for determining radio frequency parameters of the lamp while the lamp is in operation and while the performance of an atomic clock is influenced by the plasma character, with lamp spectral outputs being actively stabilized for improved vapor-cell clock performance.

Abstract: A direct-sequence-spread-spectrum (DSSS) optical-frequency-shift-keying (OFSK) code-division-multiple-access (CDMA) communication system is adapted with optical transmitters and receivers for preferred use fiber optical communication systems where modulated data and pseudorandom noise (PRN) codes are encoded in the optical domain and communicated over optical paths for increasing system capacity in wide area optical networks.

Abstract: A thermal conductor is made of copper and carbon nanotubes powders that are compressed together and then cold rolled into sheets for aligning the carbon nanotubes for providing a composite matrix having a low coefficient of thermal expansion, high thermal conductivity, and high electrical conductivity, for preferred use as a conducting heat sink, such as a laser submount, for heat sinking dissipation and electrical grounding of high-power electrical components and circuits, such as a laser diode.

Abstract: An improved radiation dosimeter device in an improved radiation dosimeter system provides a DC analog output voltage that is proportional to the total ionizing dose accumulated as a function of time at the location of the dosimeter in a host spacecraft, so as to operate in a system bus voltage range common to spacecraft systems with the output being compatible with conventional spacecraft analog inputs, while the total dose is measured precisely by continually monitoring the energy deposited in a silicon test mass accumulating charge including charge contribution prior to radiation threshold detection for improved measurement of the total accumulated charge with the dosimeters being daisy-chained and distributed about the spacecraft for providing a spacecraft dose profile about the spacecraft using the improved radiation dosimeter system.

Abstract: A uniform converter output voltage distribution power system evenly controls the individual output voltages of DC-to-DC parallel-input series-output connected converters using a uniform output voltage distribution controller including a generator for generating respective error signals from the converter output voltages using a common distribution reference signal for providing respective converter control signals connected to the converters through respective shared-bus controls for evenly distributing the power delivered by the converters that are shared-bus current-mode converters for preferably providing high output voltages. Employing a common regulation control signal, the controller can also provide system output voltage regulation, system input current limiting, proportional-voltage control, relaxed voltage uniformity, and fault-tolerant power control.

Abstract: A polyphase channelizer converts an intermediate frequency wideband signal into a complex signal that is sampled by parallel analog-to-digital converters having a bank of samplers respectively clocked by staggered clocking signals for respective converters for feeding I and Q quadrature samples to a polyphase filter bank of finite impulse response filters driving a fast Fourier transform processor for providing channelized digital signal outputs. The parallel analog-to-digital converters can operate at lower speeds but are parallel connected for effectively operating at required higher speeds. The channelizer channelizes the wideband signal using a polyphase clock for enabling high speed sampling and converting through low speed parallel analog to digital converters.