Abstract: An oscillator comprising an oscillation circuit including an oscillation transistor whose emitter is connected to the ground with respect to a D.C. signal; a detection circuit for detecting D.C. power source current supplied to said oscillation transistor; and a control circuit for controlling a D.C. bias voltage impressed on said oscillation transistor according to an output signal from the detection circuit, wherein the oscillation circuit, detection circuit and control circuit jointly constitute a negative feedback loop for sending direct current back to the source.

Abstract: A high power output push-pull microwave oscillator utilizing a plurality of tuned coaxial circuits each mounting a diode at each of two extremities and each being coupled to an output cavity of resonant frequency, f.sub.o, equal to the operating frequency. An equal plurality of second cavities, also resonant at f.sub.o are coupled to bias lines one-fourth wavelength from each of the plurality of tuned coaxial circuits to reflect a short circuit across a tee junction built into the center conductor of each coaxial circuit at the resonant frequency, f.sub.o, when the diodes are in a push-pull or out-of-phase operating mode. The short circuit is removed when the diodes operate in an in-phase mode and the resultant losses effectively suppress the in-phase mode of operation.

Abstract: A device for producing at the output of a multivibrator an electric signal the period of which is a linear function of a temperature to which is subjected the measuring probe, characterized in that said multivibrator consists in a comparator whose first input comprises the probe, said probe consists in at least two semi-conducting junctions connected two by two in parallel and in opposite directions, and the other components of the device, particularly those of the second comparator input comprising a capacitor, remains invariable.

Abstract: A transformer coupled split-ring diode modulator for digital phase modulation of a data stream in which the diodes are back-biased so as to provide additional attenuation of in-band fold-over side lobes which appear in the pass-band; the additional attenuation resulting from a cosine attenuation function which is dependent upon the switching time of the diodes and hence the bias voltage applied thereto.

Abstract: A phase locked loop type transmitter-receiver having a phase locked loop type synthesizer including a circuit in which a programmable counter, a phase discriminator, a low-pass filter, a voltage-controlled oscillator and a mixer are connected in a closed loop; wherein the mixer is connected to a reference oscillator connected to the phase discriminator through a fixed frequency divider, the mixer being adapted to mix frequencies fed from the reference oscillator and the voltage-controlled oscillator thereby synthesizing sum and difference signals thereof, the difference signal being fed to the programmable counter and the sum signal being fed to a transmitting-side mixer and a receiving-side mixer.

Abstract: An improved quadraphase shift keyed (QPSK) adaptive demodulator includes a Costas loop modified to independently cross couple the inphase (I) and quadraphase (.phi.) channels so that minimum cross talk takes place between the I and Q channels. Advantageously, the improved QPSK adaptive demodulator separates the feedback control for correcting the phasor errors in the I and Q phasors. Advantageously, the improved demodulator permits independent phase adjustment of the I and Q demodulator outputs.

Abstract: A mode-locked surface acoustic wave oscillator (MLSO) provides mode-locked, phase coherent RF signal pulses through a regenerative closed loop RF signal path which includes a surface acoustic wave (SAW) delay line having a piezoelectric substrate and a pair of signal transducers relatively disposed at a determined SAW propagation distance along a major surface thereof, an RF amplifier to provide in phase amplification of the RF pulse, and a signal expander circuit for providing an increase in the harmonic frequencies of the RF signal pulse and an increased RF pulse frequency bandwidth. The pulse repetition frequency is determined by the signal propagation time delay, provided primarily by the SAW delay line. The delay line transducers establish the center frequency of the RF signal pulse and the bandwidth of the regenerative loop limits the minimum obtainable RF pulse width.

Abstract: A phase lock loop system that includes a voltage controlled oscillator. The output of an integrator provides the voltage to a tuning port for determining the precise frequency and phase of the oscillator. In response to a change in frequency, the input to the integrator is switched off at the precise time that its output voltage reaches the value for the proper phase relationship at the new frequency. The output of a low pass filter fed by the loop's phase detector determines such precise time. At said precise time, the stabilized condition of the loop is sensed and corrected for minor deviations.

Abstract: A voltage controlled oscillator whose frequency is a function of an input voltage having a first and a second pair of switching devices coupled respectively to first and second terminals of a capacitor. The oscillator has a first leg coupled from the first capacitor terminal through first inverter means, a first NOR device and third inverter means back to the first pair of switching devices and the first capacitor terminal. The second leg is coupled from the second capacitor terminal through second inverter means, a second NOR device, fourth inverter means back to the second pair of switching devices and the second capacitor terminal. The first and second NOR devices are directly cross-connected. The first and second legs each have the same number of propagation delays and during state transition, both terminals of the capacitor are coupled to the reference potential for a brief instant of time.

Abstract: A frequency lock loop circuit has a pair of square-wave pulse generators which are clocked from a common input. The width of the pulses from the first generator is dependent on the frequency of the clocking signal; the width of the pulses from the second generator is dependent on a reference frequency. The difference in the width of the pulses from the two generators is fed back as an error signal to adjust the frequency of the clocking signal until the two waveforms are aligned. In a heterodyne receiver, the clocking signal may be the intermediate frequency signal from the mixer and it may then be adjusted by adjusting the frequency of the local oscillator in accordance with the pulse-width difference signal.

Abstract: A voltage controlled oscillator that is responsive to a crystal which is resonant at a predetermined frequency is provided. A first amplifier having first and second differential outputs is coupled to the crystal. A second amplifier having an output and a differential input for receiving a control voltage is coupled to the first amplifier. First frequency shifting means provide a predetermined phase shift for the first output of the first amplifier and couple this first output to the second amplifier. Second means for providing a predetermined phase shift is coupled to the second amplifier for providing a controllable phase shift to the output of the second amplifier and for providing a phase shift to the second output of the first amplifier. A third amplifier is used to couple the output of the second amplifier to the crystal.

Abstract: A sound communication system incorporating a triangle wave generator (TWG), a voltage controlled oscillator (VCO) and an output circuit including one or more loudspeakers. The output circuit is connected from the output of the VCO. The output of the TWG is connected to the input of the VCO to control its frequency of oscillation. The TWG can be actuated by a horn ring switch or a momentary contact switch, either of which, when closed, grounds the TWG input and causes the TWG to oscillate. A transistor switch is connected from the TWG input and a third lead from the VCO to cut off the VCO to protect the speaker(s) from damage due to low frequencies.

Abstract: A dual bandwidth loop filter includes a filter loop, resistive means, switching means for coupling and decoupling the resistive means for changing the bandwidth of the loop from a wider acquisition bandwidth to a narrower tracking bandwidth and a sweep generator for enabling the filter to provide sweep acquisition of an incoming signal.

Abstract: A test fixture for a miniature polygonal capacitor having radial and/or al terminal leads and/or conductive end electrodes, includes an insulative support on which are two brackets to which is secured a shield plate assembly. The shield plate assembly is comprised of a pair of slightly spaced parallel trapezoidal shield plates. Opposing inner edges of the plates are angularly disposed to facilitate receiving the capacitor under test, when the axial terminal leads of the capacitor enter between the shield plates. Another shield plate assembly is mounted to and under the brackets, and includes another pair of parallel shield plates disposed perpendicular to the upper trapezoidal shield plates and between the angular edges to receive any radial lead of the capacitor. Connectors for the external capacitor measuring device are secured to the conductive brackets. A stiffener plate may be secured to the insulative plate to keep it rigid and prevent capacitance changes of the test fixture.

Abstract: An improvement over an analog-to-digital converter in which a phase-locked loop (including a voltage controlled oscillator, a feedback path, and a phase discriminator) supplies clocking signals to a counter. The clocking signals are gated to the counter by a circuit which energizes a gate in response to a known reference signal and deenergizes an gate in response to the unknown source signal. The resultant count in a measure of the phase difference between the source and reference signals. Accuracy and stability derive from maintenance of a predetermined phase-locked relationship between a signal derived through frequency division of the loop output signal and the cyclic reference signal which is the reference for gating the counts to the counter. The loop output frequency is a harmonic of the frequency of the reference signal. Feedback phase control is developed through interaction of the frequency divided loop output signal with the reference signal in the phase discriminator circuit.

Abstract: An oscillator utilizing a pair of transistors interconnected with a resonance circuit in the collector circuits thereof such that by regulation of the current flow to the connected emitters, the frequency of oscillation is regulated.

Abstract: Apparatus for measuring the ignition timing of a multi-cylinder internal combustion engine of the type having a pulse generator for indicating when the flywheel is in a predetermined position with respect to top dead center and in which an input signal is obtained from one particular spark plug and employed to initiate a counting operation employing a series of pulses which have a definite frequency relationship to the speed of the engine. The counting operation is started at the time that the pulse from the selected plug is received and is terminated when the reference signal is received from the pulse generator. Provision is made for compensating for different reference angles between the top dead center position and the position at which the pulse generator produces a pulse. This is done by presetting a counter in accordance with the reference angle.The apparatus can also be used as a tachometer.

Abstract: A high-accuracy phase comparison system for noise-contaminated fixed-frequency input signals, such as Omega radionavigation signals, employs a pair of phaselock loops in which output pulses from a high-frequency oscillator are deleted at the frequency of a variable-frequency oscillator which is responsive to the detected phase difference between the associated input signal and an associated reference signal, thereby to provide a high-frequency intermediate signal which is frequency-divided to produce the reference signal continuously and free of noise. The relative phase of the input signals may be determined by phase-comparing the reference signals of the two phaselock loops or, to provide even higher precision, by phase-comparing the variable-frequency signals of the two loops.

Abstract: A phase synchronizing system having a dual mode of operation for use, for example, with "modified frequency modulation" (MFM) encoded signals wherein captive range is assured by providing a first frequency locking mode of operation wherein a voltage controlled oscillator (VCO) is first locked in frequency to a reference signal and a second phase locking mode of operation wherein the VCO is subsequently locked in phase to an MFM signal independently of the frequency assumed by the latter signal.

Abstract: A circuit for determining the slope of a signal of a predetermined minimum duration and below an upper limit by carrying out an integration first in a positive and then in a negative direction in which means are provided to insure that the integration is carried out and an output provided only when measuring a portion of the signal which is free from disturbances.