Abstract: A system for generating a signal which is a predetermined function of the capacitance of a sensor capacitor. The system comprises a sensing network including two series capacitors, at least one being the sensor capacitor. The system further comprises a switching network, and a feedback network coupled to the sensing and switching networks. The feedback network generates a feedback signal representative of the difference in charge stored on the series capacitors from a predetermined value. The switching network cyclically interconnects the feedback and sensor networks with the feedback signal and externally applied reference potentials whereby the average charge stored on the series capacitors over each cycle is substantially equal to the predetermined value. In some embodiments, the feedback signal is a linear function of the reciprocal of capacitance of the sensor capacitor.

Abstract: An ultrasonic oscillator, which can be mounted on a vehicle and which enables an oscillating element itself to generate a high ultrasonic energy, comprising a storage battery having one power line thereof grounded, a DC -- DC converter which is electrically isolated from said power lines of the storage battery and which supplies D.C. power to non-grounded power lines thereof, and a Darlington transistor circuit having a ultrasonic oscillating element connected across base and collector thereof.

Abstract: In a coaxial magnetron the resonant circuit interacting with the electrons is coupled to a stabilizing resonator operating in a mode with circular electric field. The coupling is thru a set of slots in the intervening wall. Undesirable resonances localized in the slots are damped by lossy material at the ends of the slots. Undesirable damping of the cavity mode is prevented by a conducting shield covering exposed area of the lossy material and spaced into the cavity away from the slots.

Abstract: A housing defining a first cavity forming a transmission line and a negative impedance semiconductor device terminating one end of the transmission line in a negative impedance, the housing further defining a second cavity resonant at a predetermined frequency and a means of electromagnetically coupling between the transmission line and the second cavity to couple energy therebetween, a reactive element formed between said negative impedance semiconductor device and the housing to provide a shunt susceptance to parallel resonate with the susceptance of the semiconductor device at the desired frequency and bias, and load isolator connected to the opposite end of the transmission line for transmitting RF output pulses to the RF load and for applying a DC bias thereto normally at a first level and periodically reduced to a second level for a short duration, said semiconductor device operating as a series resonant circuit with the DC bias at the first level to cause energy to be stored in the resonant cavity and

Abstract: An ozone absorbance controller for use with an ultraviolet light source, which includes a vented, trapped gas filter disposed in the optical emission path of said ultraviolet light source to absorb high energy ultraviolet rays of wavelengths below about 200 nanometers, and thereby substantially preventing the formation of ozone in the optical emission path subsequent to the filter.

Abstract: A locked hybrid junction power combiner comprises in its simplest version a single hybrid junction (0.degree., 180.degree. and 90.degree.) and an appropriate phase shifting element combining three one port oscillators (one master oscillator strongly locking the other oscillators). The combiner can be extended to combine any odd number of oscillators. Combining efficiency approaching 100% and locking figure of merit exceeding that of the master oscillator have been experimentally observed. Isolating the master oscillator from the hybrid by a circulator, the LHJ combiner can generate high microwave powers with spectral purity of the master oscillator; e.g. Impatt diode power capabilities may be combined with Gunn diode spectral purity. The combiner with an ordinary E-H waveguide hybrid junction can be employed to generate ultra-high microwave powers by combining high power tube sources.

Abstract: A receiver module including a mode launcher, a band pass filter, a local oscillator and a balanced mixer for use in the frequency range 1 GHz to 1,000 GHz, wherein the components are all connected by an insular waveguide transmission line having a conductive image plane, a dielectric waveguide attached to the image plane by a thin film of plastic, the thin film being low loss in character and having a low permittivity compared with that of the dielectric waveguide, the ratio between the thickness of the thin film and the square root of the cross-sectional area of the dielectric waveguide being in the range from about 0.02 to about 1.0.

Abstract: A phase locked loop synthesizer comprising a means for controlling a tuning means, wherein a phase difference between the outputs of a reference signal oscillator and a programmable counter means is detected by a phase detector to obtain a d.c. voltage corresponding to the phase difference, an output having a prescribed frequency is generated by a voltage controlled oscillator frequency is controlled by said d.c.

Abstract: A two pin CMOS oscillator includes an improved input protection circuit which includes pairs of back-to-back diodes coupled between the input of an amplifier portion of the oscillator and the two power conductors which energize the oscillator. Provision of the back-to-back diode pairs permits use of an internal timing capacitor coupled between the output and input of the amplifier portion of the oscillator to be partially charged by an external timing resistor to a switching point of the amplifier portion of the oscillator. When the amplifier portion of the oscillator switches, the voltage at the input may be boosted or bootstrapped to voltages considerably beyond the range of voltage between the two voltage conductors. Thus, clipping of the voltage swings at the timing node of the oscillator by the protection circuit is avoided, and improved performance is achieved, especially at high frequencies.

Abstract: Digital signals asymmetrically modulated upon a carrier, with suppressed or vestigial second sideband, are recovered at a receiver by pseudo-coherent demodulation or periodic sampling and subsequent digitization to provide a train of raw data signals X from which a train of raw quadrature signals Y is derived by digital filtration. Signals X and Y are fed to a phase corrector where they are cross-multiplied with a sine function and a cosine function of a feedback signal W, approximating a corrective phase angle .phi.(t), to yield a corrected in-phase signal X' and a corrected quadrature signal Y'. Signal X' is quantized to provide a reference signal c which, upon subtraction from signal X', produces a bipolar difference signal whose sign bit is multiplied with either the entire signal Y' or its sign bit to provide an error signal V.

Abstract: Microwave repeaters and the like are tested for third-order IM distortion by applying two, swept-frequency test-tones to the repeater. The test-tones are offset by a fixed frequency difference .delta.. A detector circuit, connected to the output of the repeater, measures the amplitude of any signal component of frequency 2.delta. which is a direct measure of the repeater's non-linearity. Because a signal component of frequency 2.delta. can be generated by second-order distortion within the detector itself, the detector includes special circuitry to cancel out any such unwanted term.

Abstract: An RF test signal generator including a driving oscillator, a pulse generr for generating narrow spikes at the oscillator frequency (such as a step recovery diode), a modulator and an attenuator. Since the very narrow pulse exhibits nearly constant amplitude in the frequency domain, a constant amplitude comb spectrum with frequency spacing at the oscillator frequency is generated so as to facilitate automated testing techniques.

Abstract: A frequency synthesizer in which the frequency of a variable frequency oscillator is controlled by means of a control signal and wherein means are provided for determining whether any frequency variation results from a drift in the frequency of the variable frequency oscillator means being provided for generating and maintaining an additional drift control signal to compensate for such drift. The drift control signal is inhibited from change either when it is detected that the control signal is in excess of that which would result solely from drift or the control signal is representative only of a quantisation error.

Abstract: A crystal controlled square wave oscillator requiring a minimum number of components, exhibiting high frequency stability, and operating at substantially a 50% duty cycle. A quartz crystal dual monolithic resonator is provided having a pair of signal electrodes and a reference electrode. The resonator is capable of oscillating in symmetric and anti-symmetric modes, points of minimum attenuation, the symmetric mode exhibiting a 180.degree. phase shift, and the anti-symmetric mode exhibiting a phase shift of 0.degree.. An integrated circuit logic gate is connected between the signal electrodes, the logic gate being of the type having low input and output impedances so as not to degrade the Q of the resonator. The logic gate provides a phase shift of 180.degree. or 0.degree. causing the resonator to oscillate in its symmetric or anti-symmetric modes, respectively, the gate switching between its two logic levels to produce a square wave output at the frequency of the excited mode.

Abstract: A high power, pulsed microwave frequency converter for a microwave communications system including a phase locked loop with a voltage controlled microwave oscillator that provides at least five watts of pulsed RF output power, the components of the loop being designed to lock on the desired RF output frequency within approximately 20 nanoseconds or during the initial portion of each pulse so that the converter coherently converts two low level signals, one or both of which may be pulsed, into a higher level narrow pulse signal at the sum or difference of the frequencies of the two low level signals.

Abstract: An ordered array of semiconductor integrated circuit feedback delay type of phase-locked recursive oscillators is arranged to furnish a correspondingly ordered discrete spectrum of mutually different resonant frequencies. The individual feedback path in each of the oscillators contains a semiconductor charge transfer device for providing most of the feedback delay. The total feedback delay in each of the oscillators is fine-tuned in the feedback path of each oscillator by a different incremental time delay element, such as an RC time delay element, which introduces an added delay that is less than that of a single transfer cycle in the charge transfer device. A phase-locking signal is fed to every oscillator, all the locking signals being derived from, and thus coherent with, a single master clock. All of the charge transfer devices are driven by a single clock pulse train whose timing can also be advantageously controlled by the master clock.

Abstract: Frequency stabilization of an oscillator by compensating for slow frequency variations due to ambient temperature variations is achieved by diverting a fraction of the oscillator output to a waveguide line section having a coefficient of thermal expansion/.degree. C which is greater than the coefficient of relative frequency drift/.degree. C of the oscillator comprising, in sequence, a variable attenuator and a movable short. The variable attenuator is used to primarily adjust the amplitude of the diverted signal by one-half the desired amount preferably without varying the phase of the diverted signal. The movable short is primarily used for signal phase adjustment while simultaneously reflecting the attenuated signal back through the attenuator and towards the oscillator output.

Abstract: A conventional phase-lock loop circuit is modified for use at microwave frequencies. The modification includes a low-frequency oscillator connected in the phase-lock loop to sweep the voltage-controlled oscillator through the frequency of the incoming signal thereby ensuring that lock-in is achieved. The oscillator is automatically turned off when "lock-in" is achieved, thereby reducing residual phase error.

Abstract: A phase-locked loop circuit in which the phase offset error arising from imperfections in the balance of the phase comparator is reduced to a minimum by a special construction of the phase comparator. The quasi-static phase error of the loop is then reduced to very low values so that the loop is particularly suited for recovering the clock frequency from synchronous pulse signals having clock frequencies of several hundred MHz.

Abstract: A circuit for synchronizing a microwave oscillator with a reference source of known frequency. The synchronizing circuit includes a phase-lock loop which compares the output of a free-running, crystal-controlled, voltage-controlled oscillator with the output of a burst oscillator. The output of the burst oscillator has a comb spectrum comprising harmonics of the reference frequency and the phase-lock loop locks onto a selected one of the comb harmonics.