Abstract: An electro-optic delay line frequency discriminator has an optical signal source providing first and second optical signals that are directed along first and second paths, respectively. In the first path, the first optical signal is converted to a first corresponding optical signal that corresponds to an electrical input signal, and the first corresponding optical signal is then delayed. In the second path, the second optical signal is delayed, and the delayed second optical signal is then converted to a second corresponding optical signal that corresponds to the electrical input signal. The first and second corresponding optical signals are converted to first and second corresponding electrical signals, respectively; and a detector, responsive to the first and second corresponding electrical signals, provides an electrical output signal from the discriminator. Optical source relative intensity noise (RIN) is canceled out and does not degrade the signal-to-noise ratio of the discriminator output.

Abstract: Using component-level test data to reduce system test. By modeling a system, sensitivity analysis reveals critical components and parameters of those components required to meet system performance parameters. Critical components are tested for these parameters, and these measurements associated with the components. Systems may be assembled which are modeled to meet the system performance parameters based on the model and the measured parameters. Systems may be assembled and calibration coefficients derived and applied from the model and the measured parameters.

Abstract: Linearizing analog to digital converter (ADC) performance using single-bit dither. Dither is summed with an input signal to an ADC by passing a serial pseudo-random bitstream through an analog filter. Dither is removed through applying correlation and digital filtering to the ADC digital output.

Abstract: Reducing writes to non-volatile storage in a system for tracking sequence numbers in a communications protocol. In a system which tracks sequence numbers, a sequence number base is kept in non-volatile storage. During normal operation, the value in non-volatile storage is not rewritten until it exceeds the base value in non-volatile storage plus a predetermined update constant. On startup, the sequence number is set to the value in non-volatile storage plus the predetermined update constant.

Abstract: Transmitter frequency locking across a full duplex communications link. An offset in one transmitter results in an offset at the corresponding receiver. That receiver offset shifts its transmitter in a corresponding manner, causing a correcting offset in the first receiver, which is used to correct the first transmitter. A first embodiment uses filtered received frequency information derived from a baseband demodulator to correct transmitter frequency. A second embodiment uses filtered frequency information from a frequency detector to correct transmitter frequency.

Abstract: Switchable path length coupler/dividers. Coupler/divider operation over multiple frequency bands is provided by using switchable path lengths. In one implementation, a Wilkinson-style device with switches to select different path lengths and therefore operating frequencies. In a rat-race style device, switches select races of different lengths, and therefore operating frequencies.

Abstract: Support structure for high frequency coaxial transmission line. A conductive bead ring is split in two halves longitudinally, containing a relief for excess glass flow and provision for locking the halves together. A glass dielectric surrounds the center conductor, which is tapered from a first larger diameter to a second smaller diameter in the region of the glass dielectric. A fixture for forming the glass to metal seal uses dams to control the positioning of the glass with respect to the taper in the center conductor.

Abstract: Asymmetric support for high frequency transmission lines. An asymmetrical support structure coaxially supports a center conductor over a ground plane using a dielectric material. Absorbing material between the dielectric and the outer conductor reduces the effects of high order modes.

Abstract: Spectrum estimates of unevenly spaced timestamped data collected over a network. Unevenly spaced data is not suitable for processing by traditional methods such as Fast Fourier Transforms. Spectrum estimates of timestamped data collected over a network are calculated using a Continuous Fourier Transform. If the time between samples is long, spectrum estimates may be computed incrementally.

Abstract: A system and method for using gamma correction in a ferroelectric liquid crystal (FLC) display uses a reduced number of different increment values for generating a Vramp signal for the FLC display without noticeably increasing error. The increment values are based upon an inverse gamma curve having a selected gamma value. Using linear interpolation, the increment values are calculated with more increment values being calculated for the beginning of the curve than the flatter end portion of the curve. In addition, an illumination period and a balance period are used so that each pixel of the FLC display is on and off for the same amount of time. As a result, the average voltage across the FLC material is 0V.

Abstract: A multi-modulus prescaler with a terminal count request input, which when set causes the prescaler to produce an output pulse with edges synchronous with the input clock. The prescaler is driven by a control circuit which produces a terminal count request output which enables the prescaler to generate a terminal count output pulse whose active edge, irrespective of the divide ratio, is always a fixed number of input clock cycles before or after the end of the prescaler control cycle.

Abstract: Correction of differences between two analog to digital converters (ADCs) in broadband intermediate frequency conversion. By stimulating a two-ADC system with a known input, the impulse response of the system is derived, and from that impulse response a finite impulse response filter is derived which corrects for mismatches between the ADCs.

Abstract: Measurement and correction of encoder errors in a servo loop. By driving the servo system on a predetermined trajectory such that encoder errors occur at frequencies outside the servo loop response, these errors are sampled. Sampled encoder error data is filtered to produce correction data, which may be applied inside or outside the servo loop.

Abstract: Display of signals containing inter-symbol interference (ISI). An input signal is modeled as comprising an ideal signal plus ISI plus error. In a first embodiment of the invention, an error signal and an ideal signal are derived from the input signal. The ideal signal is combined with the error signal producing an ideal signal with errors. In a second embodiment of the invention, a first signal comprising the ideal signal plus ISI plus error is derived. A second signal comprising only ISI is derived, and subtracted from the first signal, producing a signal containing the ideal signal plus error.

Abstract: Wideband balun suitable for millimeter wave applications. An input stripline couples energy equally into branches of a slotline. Output striplines are coupled to the branches of the slotline to produce output signals 180 degrees out of phase. A phase matching section is placed in one output stripline so that the two output striplines are electrically equivalent in length. Using radial stub terminations, the resulting balun is compact and wideband.

Abstract: Functional testing of complex digital integrated circuits. A complex integrated circuit such as a system-on-a-chip (SOC) designed using high-level tools is tested by decomposing it into functional blocks wrapped by scan path cells. A tester which includes a field programmable gate array (FPGA) or similar device is connected to the SOC to be tested, and a simulation model of a chosen functional block of the SOC selected for test is loaded into the FPGA. A test pattern is applied to the functional block of the SOC using the scan path cells, and to the FPGA simulation. The FPGA may be rapidly reconfigured to test other functional blocks of the SOC.

Abstract: Solid state illumination using closed loop spectral control. Light emitting diodes producing different colors are mounted in close proximity to photosensors. Spectral content of the light emitting diodes is measured by the photosensors, and these measurements used to adjust light emitting diode currents to achieve the desired spectral characteristics.

Abstract: Optical wavelength reference apparatus with wide wavelength range. Illuminated by a wideband source, a first reference such as absorption lines in a gas cell is used as a transfer standard, calibrating the response of the secondary reference over the range of the first reference. The performance of the second reference is extrapolated to a wider wavelength range, retaining the stability and accuracy characteristics of the first reference. Suitable secondary devices include etalons such as Fabry-Perot filters and Mach-Zehnder interferometers.

Abstract: Integral dielectric heatspreader for transferring heat from semiconductor devices. A semiconductor device is mounted to a thermally conductive electrically insulating substrate, which forms the integral dielectric heatspreader. The heatspreader is then mounted to a package or a lower cost substrate such as a printed circuit board. The integral dielectric heatspreader may also support integral transmission lines, resistors, capacitors, or other bulk components. Performance of the heatspreader is enhanced through the use of thermal vias on a printed circuit board.

Abstract: Process for generating unit names from a nonorthogonal set of units. Given a vector of exponents describing a target unit in terms of SI units, and a table of user defined units which may be nonorthogonal, one or more result unit names equivalent to the target unit are generated by recursively searching the table of user defined units, reducing the magnitude of the target in each step.