Abstract: A distortion compensation circuit for power amplifier producing a prescribed distortion component receives an input signal having at least one carrier therein in a prescribed frequency range. The input signal is applied to a first circuit path having an amplifier that produces an amplified signal with the prescribed distortion component and to a second circuit path that delays the input signal without distortion. The output signals of the first and second circuit paths are combined in a first combiner to form a signal representative of the prescribed distortion component. A second combiner forms a signal having an amplified input signal component and inverted phase prescribed distortion component responsive to the output of the first combiner and the output the first circuit path.

Abstract: Epitaxial layers are grown from a body of molten material which includes flux and layer constituent components; included in the flux are lead oxide and a small amount of boron trioxide. As compared with prior-art processing in the absence of boron trioxide, enhanced yield is realized as believed to be due to reduced adhesion of solidifying material entrained upon withdrawal of a substrate after growth. The method is particularly useful in the manufacture of magnetic domain devices designed to operate at extreme temperatures, as well as in the manufacture of magneto-optic devices such as, e.g., switches, modulators, and isolators.

Abstract: Separation between a magnetized member and a Type II superconducting member inherently manifestets stability in separation distance, in lateral direction and in attitude. Uses include levitation of fixed and moveable members as well as superconducting bearings.

Abstract: A demultiplexer for demultiplexing a multiplexed input data signal into M output channels using M sequencer means clocked from an overlapping M phase system clock. The system clock operates at a frequency equal to the input data signal rate divided by M. Each sequencer means is clocked by a unique combination of the M phase system clock signals to select one data channel from the multiplexed input data signal. Since all sequencer means circuits are synchronized to the system clock, no variable delay lines are needed to align the timing between the circuit stages. A time delay latch is provided where needed in each sequencer means to enable all channels to output data concurrently. The demultiplexer includes a real-time data-framing capability to assure that the input data is correctly mapped to the proper output channels.

Abstract: A network comprising analog amplifiers with a resistive interconnection matrix that connects each amplifier output to the input of all other amplifiers. The connections embodied in the matrix are achieved with conductances whose values are computed in accordance with the set of decomposition functions for which the solution is sought. In addition to the specified connectivity implemented. Further included is a second matrix that connects externally applied voltages to the amplifier inputs via resistors whose values are also computed in accordance with the set of decomposition functions for which the solution is sought. Still further and in accordance with another aspect of the invention, means are included for varying the amplifier gains from an initial low value to an ultimately high value in the process of arriving at a solution to an applied problem.

Abstract: A phase-lock loop includes a tristate phase detector, a filter and a voltage-controlled oscillator connected in a loop for regenerating clock signals in response to a sequence of data signals applied to the input terminal of the tristate phase detector and the loop. The tristate phase detector opens its output lead whenever a zero is applied to the input terminal of the loop. A resistor is interposed between the tristate phase detector and the loop filter to clamp excursions of a control signal, causing the filter to produce a consistent tuning control signal and forcing the voltage-controlled oscillator to oscillate at a frequency within a preselected frequency range independent of the ones density in the digital sequence applied to the input terminal of the loop.

Abstract: The novel technique for stabilizing an electronic device, e.g., a semiconductor laser, is disclosed. The technique can advantageously be used to stabilize the bias current of such a laser at or near the lasing threshold of the device. A preferred application of thus stabilized lasers is in optical communication systems. The inventive technique comprises determination of a derivative of a variable characteristic of the device operation, e.g., the voltage across a laser, with respect to a parameter, e.g., the laser bias current. The derivative is determined by a novel method. For the particular case of laser bias stabilization, the method comprises injecting one or more nonsinusoidal ac current components into the laser, and phase-sensitivity detecting the voltage changes at the ac frequencies. The method can, in principle, be used to determine derivatives of arbitrarily high order.