Abstract: A plural-differential phase shift keying (PDPSK) communication system has a transmitter (22) for encoding digital data as plural differentials of phase between successive pairs of channel symbols of a carrier, and a receiver (24) with a plurality of phase differential detectors (32, 48) connected in cascade for determining the plural differentials of phase of the incoming signals to achieve a bit error rate independent of frequency offsets and thereby an improved rate of signal acquisition.

Abstract: A digitally switched gain amplifier designed for use in binary controlled systems. The amplifier is designed for fabrication as a monolithic integrated circuit. The amplifier provides gain that varies in discrete levels in a binary manner under direct control of a digital word. The smallest resolution, or distance between gain steps, is one decibel and the maximum amount of gain reduction is determined by the number of stages included in the amplifier. The incremental resolution of the amplifier allows for the amplifier to keep a received signal at a constant level with a digital word. Thus, eliminating the need for digital to analog conversion.

Abstract: An improved avionics fluorescent lamp including a fluorescent tube having a resistive element disposed on its exterior and a terminal block for receiving an inserted fluorescent tube, the terminal block having a semi-rigid electrical contact for contacting the resistive element when the tube is inserted inside the terminal block. A plurality of connectors are disposed on the exterior of the terminal block for providing easy connection between the lamp wiring harness and the filament pins of the fluorescent tube and the resistive element by the semi-rigid connector. And a display device having the fluorescent lamp of the present invention disposed therein where the resistive element is disposed on the reflector side of the tube.

Abstract: A variety of embodiments of varactor diodes are disclosed ranging from an N.times.N matrix assembly of individually packaged diodes arranged in N rows and columns to a multi-continuous layered varactor. The matrix assembly varactor has N rows of discrete devices electrically coupled in parallel and multiple rows vertically aligned and electrically coupled in series to each other. The overall matrix assembly capacitance equals the individual diode capacitance of such assembly. When used as a tuning component across a tank coil transmission line, the RF voltage across any device in the matrix assembly is equal to the tank voltage divided by N.

Abstract: An avionics display device having a stowable rotatable locking handle disposed therein for facilitating quick and easy installation and/or removal of the display device.

Abstract: A communication system and a method for using an approximating frequency synthesizer with frequency correction by digital signal processing (DSP) means to provide a radio transmitter or receiver with rapid high resolution tuning capabilities. A user selects a frequency upon which he wishes to transmit or receive information. An approximating synthesizer is used to provide an RF injection frequency. A radio controller interprets the user selected frequency and determines the closet available approximating synthesizer frequency. The controller commands the approximating synthesizer to the determined available frequency and calculates the difference in the determined available frequency and the user selected frequency. The calculated difference or error is passed on to the DSP for correction during frequency mixing in a single or multiple step process.

Abstract: An improved dimmable dual filament fluorescent lamp including a first filament and a second filament with automatic current switching between the first element and the second element when the first element opens due to a failure and further having a separating cold cathode getter plate disposed between the first filament and the second filament.

Abstract: A bidirectional amplifier apparatus comprising a plurality of diodes located in a ring structure around an amplifier device to be switched. Each pair of diodes are spaced approximately one quarter wavelength, at the frequency to be passed, in order to maximize isolation across the "off" diode pairs. Use of transmission line devices of approximately one quarter wavelength, at a desired frequency, provide a high impedance at the desired frequency while attenuating higher frequencies where the transmission line devices length approach one half wavelength. The use of the transmission line devices also provide a ground bias for the paired diodes.

Abstract: An electrical circuit provides a constant phase shift between two output signals derived from a common input. The output signals are designed to provide a constant phase shift at constant amplitude over a very large frequency range. The common input is provided to both a non-shift channel and a phase-shift channel. The non-shift channel comprises a fixed attenuator circuit that provides a non-shifted output signal. The phase shift channel comprises a low-pass RC filter circuit that provides a phase shifted output signal. The two output channels are connected by a transformer phase detector that generates an error signal. The error signal is input to an operational amplifier that provides a phase-shift control signal to the RC filter circuit of the phase-shift channel.

Abstract: An apparatus for providing illumination to flat panel displays having a multi-walled encasement device, lighting means and a flat panel display. The multi-walled encasement device may be of a variety of shapes and serves to support the lighting means within the cavity formed by its walls. The fluorescent bulb is fabricated into a circular design and placed within the multi-walled encasement device thereby providing uniform light intensity across the flat panel display attached to the encasement device. The encasement device may contain convex or concave contouring to better direct or concentrate light wave intensity to the flat panel display.

Abstract: A tri-phase combiner/splitter system that has similar advantages to presently available binary combiner/splitter systems which uses quadrature couplers. Notably, the combiner input Voltage Standing Wave Ratio ("VSWR") remains at 1:1 for identical mismatch impedance at the output ports. There is also a complete cancellation of back-door intermodulation components for identical output device nonlinearities. An innovative wideband, 0.degree. three way combiner/splitter is the basic building block of the present invention. To achieve equal port impedances, a new wideband transmission line transformer is used. By using 60.degree. or 120.degree. phase equalization networks at the three, 0.degree. output ports, this device is converted to a wideband tri-phase combiner.For moderate bandwidths, a coupled transmission line version is possible using meandering strip lines in the same fashion used in quadrature coupler design.

Abstract: A control knob assembly primarily for use with devices utilizing flat panel display technology, each assembly having means for manipulating the electronic apparatus by using remote sensing capability to transfer control knob input into a control signal. The assembly is mounted on a bezel, affixed to the front side of the flat panel display and cooperates in conjunction with a plurality of photodiode devices located near the back side of the flat panel display. Photodiodes are located with respect to knob location so as to be able to detect knob adjustment by monitoring a reflected signal that is alternatively disrupted by knob adjustment. The photodiode devices may be infra-red light emitting diode as are well known in the prior art. Circuitry to the photodiode device is used to transmit detected knob adjustment to the appropriate device control circuitry.

Abstract: An improved TFEL matrix panel drive technique, for improving the brightness output, which utilizes a voltage wave form applied to the row which possesses a first initial peak voltage region, which when combined with a column voltage, exceeds a predetermined threshold voltage for the emission of luminescence, the first initial peak voltage region being relatively short in duration and higher in voltage, with respect to a secondary extended plateau region which when taken in combination with any column voltage is below the predetermined threshold for emission of luminescence. The technique accomplishes its result by allowing for the application of voltage signals to more than one row at a time however only one row is permitted to possess a first initial peak voltage region at any one given time.

Abstract: An apparatus and method of calibrating a digital to analog converter including means for establishing and storing a minimum and maximum analog endpoint value slightly in excess of the desired operating range of the DAC and then scaling each respective raw data point of the DAC within the established endpoint values.

Abstract: An advance in-flight windshear detection system which utilizes a scanning mirror to direct infrared energy located in a three dimensional space in front of the aircraft which is divided into a plurality of variable columns, onto a linear array of photoconductive infrared detectors, the detector emitting a signal representative of the radiant energy at various points in said variable located columns, and a computer for generating a displayable representation of the air temperature in front of the aircraft, the computer further capable of interpolating and extrapolating the air temperatures in the three dimensional space based upon the known and or calculated lapse rate; and a display device for graphically displaying the air temperature in front of the aircraft and above the flight path vector so as to provide a more accurate indication of windshear which is less affected by the uncertainties arising from measuring air temperature in a typically more turbulent region along the flight path vector as the aircraf

Abstract: Improved backlighting of liquid crystal and other flat panel displays is accomplished by lighting the back of the LCD using lamps located at the ends of the LCD. The LCD is mounted over a channelized frame, and a light transmissive window covers each end of the channel, the combination forming a sealed LCD unit. The LCD unit is mounted in a panel which has reflectively-coated recesses on each side of the LCD unit containing incandescent lamps and opening in registry with the windows in the LCD. The windows are constructed of two back-to-back sheets of prism film whose function is to reject light impinging at greater than the critical angle of the film. The light from the lamps is thereby better distributed along the full width of the LCD, which eliminates bright and dark spots on the LCD. The LCD channel is provided with a centrally-located, raised luminaire to further diffuse light from the lamps in the center of the LCD.

Abstract: A digital amplitude modulator receives a plurality of phase coherent input signals from a plurality of amplifiers (A1-An) respectively representing the bits of a plural bit digital word and converts them to a single output signal on an output with a first plurality of transformers having transformer ratios which vary substantially in accordance with a power of two corresponding to the significance of the bit represented by the input signal being converted thereby and a second plurality of transformers having primaries connected to the first plurality of transformers, respectively, and secondaries all connected in series together to an output terminal and transformer ratios which vary in substantial accordance with the same powers of two that the transformer ratio of the first plurality of transformers to which they are connected vary.

Abstract: A color matrix display including a color matrix reflective filter (10) having groups of reflective red, green and blue (R, G, B) color elements (12) arranged in subgroups (20). The elements (12) of each color group (R, B, G) in each subgroup (20) are aligned with pixel subgroups of a matrix control element or LCD (18). The color elements (12) of the reflective filter transmit light (26) of their associated color to an aligned pixel associated with that color and reflect back (30) light of other colors to a reflective light assembly (16) for reuse. The color matrix reflective filter (10) is made by selectively exposing selected areas of a holographic optical element, or HOE, with a light of colors other than the color desired to be transmitted by that element (12) of that selected area.

Abstract: An improved method and apparatus for drawing energy management circles on electronic flight instrument system displays which includes a microprocessor for making several initial inquiries regarding the orientation of the circle with respect to the display and issuing write or don't write commands for each point on the circle without the need for individually analyzing each point as to whether it is located on the display screen.

Abstract: An improved fly by wire or fly by light system which provides for a smooth manual override of the autopilot function by allowing the pilot to modify the autopilot command to the control surfaces by physically manipulating the yoke to a position different than that commanded by the autopilot.