Abstract: The disclosed apparatus for determining the acceleration induced changes in the electrical characteristics of a quartz crystal includes all the apparatus necessary for subjecting the crystal to random acceleration forces and simultaneously determining the electrical characteristics of the crystal. More specifically a vibration generator is provided to subject the crystal under test to random vibrations of a predetermined acceleration. A low noise signal generator provides a signal at the resonant frequency of the crystal. The crystal couples the output of the low noise signal generator to a phase detector to determine the phase shift of the crystal. The output signal of the phase shift detector is analyzed to determine the acceleration versus electrical characteristics of the crystal under test.

Abstract: A strip transmission line power divider having an isolated port remote from the output ports is disclosed. Power division is provided by a two branch strip transmission line. A coaxial transmission line coupled between the output ports of the divider is coupled to an isolated port where terminating resistors of any convenient power rating may be used.

Abstract: A radiation pump recovery system for a double pass pump Raman oscillator is described incorporating a polarizer and quarter waveplate positioned in the optical path of the input pump radiation and functions to separate the reflected pump radiation coming back from the Raman oscillator along the input optical path from said input optical path. In an alternate embodiment the recovery system may include an additional quarter waveplate and mirror to permit unpolarized pump radiation to be separated into two polarizations to drive two Raman oscillators and whereby the reflected pump radiation coming back from the Raman oscillators along the respective input optical paths is separated from said respective input optical path and recombined into a single beam. An alternate embodiment utilizes the rejected pump energy in a Raman amplifier to provide optimal conversion efficiency.

Abstract: A lithographic process utilizing soft x-rays or ions to achieve high resolution is disclosed. The process is particularly useful and semiconductor processing where high resolution is required to achieve a high density. The process utilizes a mask to selectively expose a photoresist to soft x-rays or flood beams of ions. The mask comprises a thin metallic foil supported by a frame such that the foil is in tension. The frame includes optical alignment keys. A second patterned layer of metal is affixed to the foil to form areas which are nontransparent to the soft x-rays or flood ion beams for delineating the elements of a semiconductor circuit, for example. This permits the mask to be optically aligned using conventionally techniques with high resolution being achieved do to the short wavelength of the x-ray radiation or the ion beams.

Abstract: A raster scan display system for overlapping images. A non-interfering erasure and relocation capability is included by providing a multi-level digital signal specifying the status of each pixel of the display and the number of display images which overlap at each pixel. For each image to be displayed the associated stored digital word is incremented one count. For each image to be erased the associated stored digital word is decremented one count. An image or a portion of an image is relocated by decrementing the data word associated with the current location and incrementing the data word associated with the new location. Expanding the data storage permits the same technique to be applied to multi-color display systems.

Abstract: Apparatus for scrambling and descrambling the video portion of TV signals is disclosed. The video portion of the TV signal is stored in a serial memory such as a charge coupled device. Scrambling is accomplished by shifting the end portion of the lines of video to the beginning by recirculating the data stored in the charge coupled devices for a portion of a line of the video signal. Two charge coupled devices are provided so that when the data stored in one device is being recirculated for scrambling the subsequent line can be stored in a second device. Descrambling is an inverse operation and is accomplished in essentially identical hardware.

Abstract: A circuit for phase shifting a signal has been described incorporating a four port network containing a plurality of impedances wherein each impedance is provided by a transmission line having a predetermined characteristic impedance and predetermined phase length and wherein an input signal is coupled to the first port, an output signal is coupled to the second port, a first diode is coupled to the third port, a second diode is coupled to a fourth port and means for biasing the diodes to be conducting at first times and nonconducting at second times. The phase shifter circuit overcomes the problem of phase error, amplitude modulation and voltage standing wave ratio over a predetermined frequency range.

Abstract: A high frequency, transformer capable of operating at high power levels is disclosed. Conductive ribbons including end (terminal) sections which permit the terminal leads of a plurality of windings to be extended from the windings in an overlapping relationship and in the selected order is utilized for the windings. Preferably, the core is formed of a material having low eddy current losses and characteristics permitting the core to be molded such that the windings are substantially surrounded by the core with the exception of small openings through which the leads extend.

Abstract: A phase shifter utilizing a circulator and electronic switches to change the length of a transmission line is disclosed. More specifically, a section of transmission line terminated in a short circuit is coupled to one port of a circulator. Energy exiting the port is reflected by the short circuited transmission line to introduce a phase delay in the signal. A PIN diode is utilized to provide a switchable short across the transmission line to reduce its electrical length thereby reducing the phase delay.

Abstract: A test system utilizing modulators responsive to signals to be tested positioned between a source of electromagnetic radiation and a sensor with the signal to be tested coupled to the input of the modulators. Preferably the modulators are positioned in optical wave guides with the modulators being electric-field operated devices to prevent any significant loading of the signals to be tested. Disclosed embodiments utilize light as the electromagnetic energy with lithium niobate substrates having titanium diffused therein forming the optical wave guides. Modulators are provided by planar electrodes affixed to the surface of the lithium niobate substrate to change the electric field across the optical waveguide. Coupling is conveniently provided to the wave guides through fiber optic bundles.

Abstract: A snubber circuit for accepting current from the load at times when switching elements of a bridge switching amplifier are being turned off was described incorporating a capacitor and diode for directing the current back to the power supply wherein the capacitor is precharged by an inductor and capacitor and at least one diode to provide resonant charging of the capacitor. A switch is also provided for activating or deactivating the snubber circuit in response to a control signal. The snubber circuit overcomes the problem of excessive power dissipation in resistors of conventional snubber circuits.

Abstract: A system for reducing the bandwidth and simultaneously transmitting a plurality of signals through a common transponder. The system is particularly useful for the transmissions of multiple TV signals via a geostationary satellite. Prior to transmission the bandwidth of each of the signals to be transmitted is reduced by one half by deleting every other line and expanding each of the remaining lines to cover a time interval normally occupied by two lines. After transmission through the satellite, each of lines is recorded at a first rate and read back at a higher rate to reduce the time interval of each line to its original value. Each line is repeated twice to reconstruct a TV signal having the same format at the original signal.

Abstract: A test system and method for comparatively analyzing complex signals especially those composed of combinations of pulsed signals related to the operational status of apparatus whose operational status is to be determined, is disclosed. In the preferred embodiment a probe, preferably a capacitive probe, is utilized to sense the electric field generated by electrical apparatus. The output signal of the probe is periodically sampled to generate an array of digital signals. This array is processed using Walsh transformations to generate a reference Walsh transform. A second data base is then generated by similarly sampling the electric field generated by an apparatus whose operational status is to be determined. The second data base is then processed to generate a comparison Walsh transform. The operational status of the apparatus whose operational status is to be determined, is then determined by comparing these Walsh transforms.

Abstract: An address generator for corner turn memories which are dimensioned in integral powers of two is disclosed. A binary adder is utilized to combine the current address with a binary number which specifies the amount to be added to the current address to generate the next address of the corner turn sequence. Limiting the dimensions of the memory to integral powers of two simplifies the circuitry necessary to generate the corner turn address sequence.

Abstract: An improved addressing circuit for memory system using a plurality of integrated circuit memory arrays is disclosed. Typical integrated digital memory arrays include an address input which accepts a digital signal which identifies the storage locations in the array and an array enable input signal. In typical arrays, the time to respond to the address input signals and the array input signal is different with decoding of the array enable signal typically being considerably faster than decoding of the address signal. In the disclosed addressing scheme, the arrays comprising the system are arranged such that a first portion of the system address signal is decoded to select the array with the remainder of the address portion serving to select the storage location within the selected array. The addressing is arranged such that for a sequentially addressed data block, a word is read from each of the arrays before the address inputs to the arrays is changed.

Abstract: The invention comprises a method for coupling an optical fiber to an optical device. Ends of optical fibers are ion polished. Micro-manipulators are used to position the polished end in abutting relationship with the optical device. A liquid which contains glass constituents is used to coat the junction of the optical fiber and the optical device. The liquid is subjected to a temperature cycle which fuses the glass constituents to the optical fiber and to the optical device.

Abstract: Quadrature detectors are subject to errors due to both phase and amplitude mismatches. The disclosed invention comprises a system for sampling the I and Q channel output signals of a quadrature detector and processing these signals to generate a signal which has a predetermined relationship to the phase error in the in-phase and quadrature signals independent of amplitude mismatches in said signals. The necessary mathematical computations can be performed by analog or digital circuitry. Phase error correction can be accomplished by a servo loop which changes the relative phase of the reference signals to the I and Q channels or by mathematically correcting the I and Q channel output signals to reduce the phase error.

Abstract: The invention comprises an electrical connector composed of a plurality of individually replaceable modules. Each of the modules includes a central portion where either male or female type connector pins can be mounted. The edges of the modules includes locking means permitting each of the modules to be secured to an adjacent module. Each of the modules may have different types of connector pins. This structure permits a connector of any desired size or pin configuration to be conveniently assembled from individual modules.

Abstract: A system for testing a wave guide arc detecting circuit for a microwave system is disclosed. Testing is accomplished by utilizing a pulsed laser source to generate pulses of optical energy which are used to simulate an electrical arc across the wave guide. The laser source is then positioned such that the pulsed output signal impinges upon the wave guide arc detector circuit to be tested. This is most advantageously accomplished by affixing the wave guide arc detector circuit to the wave guide in a fashion similar to normal operation. This enables the arc detecting circuit to view the end of the wave guide through the interior of the wave guide. The laser source is positioned such that the output pulse of the laser source impinges on the open end of the wave guide. The operational status of the wave guide arc detecting circuit is determined by measuring the elapsed time between the generation of the output pulse of the laser and the detection of the pulse by the arc detecting circuit being tested.

Abstract: An optical system providing multiple wavelength dependent optical paths and using graded index of refraction optical elements is disclosed. The dimensions of the graded index of refraction optical elements are selected such that each optical path is one focusing length. Dichroic elements are utilized to differentiate between the optical paths on a wavelength basis.