A continuously variable phase shifter including a phase splitter which provides four quadrature signals of an input signal, a summing resistor and a phase control diode matrix between the phase splitter and the summing resistor. The matrix includes a separate diode in the path of each of said four signals. The four diodes are connected to two terminals at which DC control voltages are applied to control the states of conduction of the four diodes. The diodes are controlled so that only one diode...

A pulsed excitation voltage circuit for a strain gauge bridge is disclosed using a transformer having its primary winding adapted to receive an excitation timing pulse and two secondary windings to turn on two transistor switches adapted to connect positive and negative voltage sources of equal amplitude to opposite ends of the bridge. Voltage limiting diodes are connected to output terminals to limit common-mode voltage spikes resulting from different turn-on and turnoff times of the transistor...

A method and apparatus is disclosed for bit synchronization of a received PCM communications signal, without requiring a separate synchronization channel in the communications signal by digital correlation of the received square-wave signal with a predetermined number of phase displaced replicas of its expected form. Each phase displaced replica is correlated with the input signal to determine which phase displaced replica produces the largest correlation signal. In carrying out the correlation ...

A digital function generator capable of generating any arbitrary single valued function representable by an independent and a dependent variable is disclosed. A state signal generator produces a plurality of output state signals corresponding to quantized sequential values of the independent variable. Predetermined ones of the quantized sequential signals correspond to predetermined incremental values of the dependent variable. A decoder monitors the output of the state signal generator and prov...

An infrared photodetector is formed of a heavily doped p-type Ge.sub.x Si.sub.1-x /Si superlattice in which x is pre-established during manufacture in the range 0 to 100 percent. A custom tailored photodetector that can differentiate among close wavelengths in the range of 2.7 to 50 microns is fabricated by appropriate selection of the alloy constituency value, x, to establish a specific wavelength at which photodetection cut-off will occur.

Self-protected electrodes which inherently limit field-emitted currents to a safe value and also stabilize such currents are disclosed. The electrodes are characterized by a plurality of columnar conductors connected at one end to a common potential source. The electrodes are insulated from one another along their lengths whereby the effective or exposed surfaces thereof are subdivided into a mosaic of conducting patches which are insulated from one another.

A multiple phase modulated carrier tracking loop for use in a frequency shift keying system is disclosed in which carrier tracking efficiency is improved by making use of the decision signals made on the data phase transmitted in each T-second interval. The decision signal is used to produce a pair of decision-feedback quadrature signals for enhancing the loop's performance in developing a loop phase error signal.

A tool for use in lifting a pin-supported, electronic package mounted in juxtaposition with the surface of an electronic circuit board. The tool is configured to be received beneath a pin-supported package and is characterized by a manually operable linkage, including an elongated body within which an elongated, rigid link is supported for axial reciprocation and a pivotal link pinned to the body and supported for oscillation induced in response to axial motion imparted to the rigid link. A lift...

A miniature multichannel biotelemeter system includes a transmitter unit in which signals from different sources are sampled to produce a wavetrain of pulses in which sample pulses of all the signals are separated by sync pulses. The pulses amplitude modulate a radio frequency carrier which is received at a receiver unit. Therein the sync pulses are detected by a demultiplexer which routes the pulses from each different source to a separate output channel wherein the pulses are used to reconstru...

A system capable of generating every possible data frame subperiod and delayed subperiod of a data frame of length of M clock pulse intervals (CPIs) comprises parallel modulo-m.sub.i counters. Each m.sub.i is a prime power divisor of M. Each m.sub.i =p.sub.i .alpha..sub.i is a cascade of .alpha..sub.i identical modulo-p.sub.i counters, where m.sub.i p = p.sub.i .sup..alpha. . The modulo-p.sub.i counters are feedback shift registers which cycle through p.sub.i distinct states. By this organizatio...