Abstract: An effective high frequency oscillator is made of a plurality of Josephson devices. A high frequency converter as a high frequency circuit is made of the high frequency oscillator, nonlinear superconductor devices, and transmission line. Josephson devices are connected in parallel to make a superconductor module. Then superconductive modules are connected in series for high frequency via a phase locking circuit such as a thin film type capacitor to make the high frequency oscillator. Consequently, the high frequency oscillator is used as a local oscillator for a frequency converter. The high frequency system comprises a high frequency package housing a high frequency circuit, a cooling unit including a low temperature stage in thermal contact with the high frequency package, and a shielding case for housing the high frequency circuit and the low temperature stage. The high frequency system of the present invention provides a small-sized and power-saving high frequency circuit having operational stability.

Abstract: An oven assembly for a crystal resonator and oscillator utilizes a thermally symmetrical design to provide a high thermal gain. The oven assembly includes an encasement that forms a hermetically sealed oven chamber that is substantially cylindrical. Concentric with the oven chamber is an annular oven mass that functions as a heat reservoir for the crystal resonator that is contained within the oven mass. The cylindrical oven chamber and the concentric annular oven mass provide two levels of circular symmetry that help achieve a thermally isotropic oscillator environment. Wide-area uniform heat transfer promotes high thermal gain and minimizes thermal gradients. Another factor is the geometry and circuitry for temperature monitoring. Temperature sensors are equidistantly spaced from each other and are equidistant from the center of the oven chamber. Signals from the various thermistors are averaged to provide a more accurate temperature determination for regulating the heaters.

Abstract: A substantially sealed frequency source (10) including a crystal oscillator (14) and a programmable IC (22) thermally and electrically coupled on a substrate (12). The IC (22) is accessed through an interface (26) with programming signals (42) so as to provide an analog temperature control signal (34) and a crystal oscillator frequency adjustment signal (36). The substrate (12) maintains a substantially constant temperature at a turning point (82) on a frequency-temperature response curve (80) of the crystal (64). The IC (22) allows programming of the source (10) after sealing to compensate for shifts in the crystal frequency-temperature response (80) due to sealing. The IC (22) provides electrical correction of the substrate temperature setpoint and the crystal oscillator frequency without mechanically or thermally disturbing the internal components of the source (10).

Abstract: A heater controller for an atomic frequency standard provides accurate and stable temperature control for an assembly, such as a lamp assembly, by regulating a current flow through a heating device so as to maintain a substantially constant heating power output during start-up and by reducing the DC temperature errors of the system during normal operation. The heater controller includes an integrating amplifier which generates an amplified temperature signal based on the temperature of the lamp assembly. The heater controller further includes a device for receiving the amplified signal from the integrating amplifier and establishing a control voltage having an upper limit based on a voltage of the heater power supply.

Abstract: An oscillator is isolated from external mechanical and thermal effects by rrounding the oscillator on all sides with an aerogel insulation structure that provides both thermal insulation and vibrational isolation above some predetermined low frequency limit which is a function of the mass of the oscillator and the nature of the aerogel insulation structure.

Abstract: A frequency standard generator includes a voltage controlled crystal oscillator for generating high stability output signal to be used as a standard frequency signal, a satellite wave receiver which receives a radio wave from a satellite which includes a highly accurate satellite time signal and reproduces the satellite time signal to be used as a reference for the voltage controlled crystal oscillator, a frequency divider which divides the output signal of the voltage controlled crystal oscillator by a dividing ratio arranged to generate a crystal time signal which is identical in frequency to the satellite time signal, a time interval measuring circuit which measures a time interval which is a phase difference between the satellite time signal and the crystal time signal and generates a digital signal indicating the phase difference, a frequency control processor which arithmetically determines control data based on the digital signal from the time interval measuring circuit such that the phase difference m

Abstract: The present invention provides for methods of increasing the frequency vs. temperature ("f vs. T") stability of Oven Controlled Crystal Oscillators to levels which are superior to atomic frequency standards and 100 to 10,000 times higher than that currently available from the best crystal oscillators. This method encompasses the steps of making an SC-cut quartz resonator with upper and lower turnover temperatures at or near the resonator's inflection temperature, inserting the resonator into a high-stability oscillator circuit, placing the circuit into a high-stability, high thermal gain oven and adjusting the oven temperature to a set-point at or near one of the resonator's turnover temperatures.

Abstract: A microwave oscillator with loop frequency conversion to and signal amplification at an intermediate frequency. A high-Q sapphire dielectric resonator is coupled in a frequency conversion loop between a pair of balanced mixers. One mixer comprises a downconversion mixer from an output frequency F.sub.0 to an intermediate frequency F.sub.IF, while the other mixer comprises an upconversion mixer from the intermediate frequency F.sub.IF to the output frequency F.sub.0. The frequency conversion loop additionally includes a low 1/f noise IF amplifier coupled between the mixers. The two mixers receive a local oscillator signal having a frequency F.sub.0 .+-.F.sub.IF from a microwave reference signal generator. In such an arrangement, an output frequency section and an intermediate frequency section is provided. The output frequency section includes the sapphire dielectric resonator and an output power divider while the intermediate frequency section includes the two mixers and the IF amplifier.

Abstract: An oscillator is isolated from external mechanical and thermal effects by surrounding the oscillator on all sides with a thermally insulating medium such as an aerogel insulation structure that provides both thermal insulation and vibrational isolation. Power is supplied to the crystal oscillator without wires. Wires are eliminated by using modulated microwaves or millimeter waves to transmit power and signals into and out of the oscillators, such as with small, efficient transceivers utilizing microwave or millimeter-wave integrated circuits or use of solid-state light sources and photodetectors in combination with thermal insulation which is transparent to the wavelengths of the electromagnetic radiation.

Abstract: Chip logic, a frequency multiplication and/or division, a temperature sensing circuit, and a power management circuit, are integrated on a very large scale integrated (VLSI) circuit chip. The temperature sensing circuit directly measures the chip temperature, producing a temperature output signal. The power management circuit, which is connected to the temperature sensing circuit and to the chip logic, responds to the temperature output signal and to a functional state of the chip logic to generate a control signal to the PLL. The PLL responds to the control signal to either stop the clock signal or modify the operating frequency of the clock signal, depending upon the state of the control signal.

Abstract: An RF power-generator system for the frequency range of 2 to 30 MHz and a programmable sinusoidal power output of 0 to 1000 W. The system is constructed of modules (10, 30, 50, 70 and 90) accommodated in a shallow parallelepipedal housing (1) with a capacity of 4.6 l. The housing essentially comprises two lateral lengths (4) of structural section, a sheet-metal front (6), a sheet-metal bottom (5), and a lid. A crystal-controlled power-oscillator module (10) communicates by way of an RF line (121) with an intermediate module (30). The intermediate-amplifier module communicates by way of still another RF line (122) with a terminal power-amplifier module (50). The terminal power-amplifier module communicates by way of still another RF line (123) with a high-power filter (70). The filter communicates by way of still another RF line (124) with a high-power directional coupler (90). The RF power output can be intercepted at an RF plug (2).

Abstract: A crystal oscillator for generating an output oscillation whose frequency is maintained constant independently of the variation of temperature including a first quartz vibrator arranged in a heating unit which includes a thermostat and vibrating at a fundamental frequency, a second quartz vibrator arranged also in the same heating unit and vibrating at a third overtone frequency, a frequency multiplying circuit for multiplying the fundamental frequency by three, a frequency comparator for comparing the fundamental frequency multiplied by three with the third overtone frequency to derive a frequency difference which represents a temperature of the thermostat, and a temperature controlling circuit for controlling the temperature setting of the thermostat in accordance with the detected frequency difference. Any one or both of the fundamental and third overtone oscillations may be derived as an output oscillation.

Abstract: A system for adjusting the frequency of transmissions between a base station and a mobile station. The mobile station detects the frequency of the signal received from the base station, determines whether the signal was received from the current base station and adjusts the output signal of a local crystal-controlled reference oscillator in accordance with the difference between the frequency of the output signal and the frequency of the received signal.

Abstract: A resonator heating element is attached to the surface of a crystal resonator. Resonator temperature sensing may be accomplished either by a sensor attached to the crystal enclosure, or through dual mode temperature sensing, or by both. A control system converts the sensed temperature into a series of variable-width pulses applied to the resonator heating element. Thus, the temperature sensing mechanism(s), control system and heating element comprise a temperature feedback control system which allows the crystal to stably operate at or very near its desired temperature. In an especially preferred embodiment, an integrated circuit from a switching power supply may be used in a novel manner to perform certain of the functions in the temperature feedback control loop. Plural resonators may be present in the enclosure, one of which may be directly involved in temperature sensing. In other embodiments, a ring-shaped insulative structure may additionally be disposed between the resonator and its enclosure.

Abstract: A piezoelectric resonator (1) consists of a piezoelectric reed (2) encased in a housing composed of a cap (7) and a base (8). The resonator (1) is placed in a thermostatically controlled containment (10). The thermostatically controlled containment (10) consists of an inner cell (40) which is screwed into an outer cell (30). These cells (30, 40) each possess sides (34, 44) and a bottom (35, 45). A thermal seal (16) is inserted between the bottom (35) of the outer cell (30) and the bottom (45) of the inner cell (40). The cap (7) of the resonator is soldered over its entire outer surface to the sides (44) and to the bottom (45) of the inner cell (40). The thermostatically controlled containment (10) is placed in a secondary containment (21). A narrow space (22) separates the two containments (10, 21), and the surface of the contact between the two containments is as small as possible. The invention is used for ultrastable on-board oscillators.

Abstract: A quartz crystal resonator is situated in an enclosure whose interior is substantially a vacuum. A heating element is attached to the crystal surface. A sensor is attached to the crystal enclosure, and may be sandwiched between the crystal enclosure and the circuit board to which the crystal enclosure is attached. A control system converts the sensed temperature into a series of variable width pulses applied to the resonator heating element. Thus, the sensor, control unit and heating element comprise a temperature feedback control system which allows the crystal to operate at or very near its desired temperature. Further, the crystal enclosure may be substantially surrounded by an external material insulator. The external material insulator maximizes thermal resistance between the sensor and the environment in comparison to the thermal resistance between the crystal and the sensor.

Abstract: A heating or, respectively, cooling device is realized by a Peltier element and is assigned to a crystal oscillator and driven by a processor with the assistance of a temperature sensor such that the crystal exhibits one of two selected temperatures lying closest to the ambient temperature. A compensation value is stored in the memory of the processor for each of the crystal temperatures selected from an operating temperature range. This compensation value effects the compensation of the frequency deviations of the crystal oscillator that are caused by temperature fluctuations.

Abstract: A low phase jitter oscillator which is adjustable in frequency is disclosed. The oscillator comprises a logical OR gate having a feedback loop adjustable in length between the inverted output of the gate and the input of the gate. Using this configuration, the output changes state once every 1/2 T seconds wherein 1/2 T is equal to the propagation delay through the feedback loop and the OR gate. The frequency of the oscillator can be adjusted by adjusting the length of the feedback loop which correspondingly modifies the propagation delay through the feedback loop and thus the frequency of the oscillator output.

Abstract: A disciplined frequency standard includes an adaptive control loop to correct for ambient temperature effects. The crystal resonator of the disciplined frequency standard is enclosed within an oven which is heated by current applied through a resistive heater. A small current sensing resistor is inserted in series between the oven current source and the oven heater to produce a voltage drop which is proportional to oven current. An analog temperature signal T is derived from the voltage drop and is multiplied with a frequency/temperature parameter dF/dT to produce a compound temperature correction factor UT. The frequency/temperature parameter U and an aging drift parameter B are measured in control loops which are weighted by averaging time parameters K, L, respectively. The measured values of B, U are stored and the weighting factors K, L are adjusted according to the variance of the most recent measurement from the stored average.

Abstract: A microwave frequency discriminator, i.e. an electronic device for directly transforming frequency modulation on a microwave carrier into a demodulated lower frequency signal. The discriminator is similar to a Travis discriminator and includes an inlet microstrip line, two resonant circuits (R.sub.1, R.sub.2) constituted by dielectric resonators and coupled to said inlet microstrip line to receive the modulated microwave signal, two outlet microstrip lines coupling each resonator to a respective microwave detector circuit, said detector circuits including loads (r.sub.1, r.sub.2) in series-opposition in the manner of a Travis discriminator.

Abstract: A processing system (10) includes a backplane bus (13) that defines a plurality of locations (20-31) implemented as backplane slots each for connecting any option module (41) thereto. Each slot includes contact pins (201a-d) that carry binary logic levels forming a different digital number at each slot. Option modules include their own source of timing signals (220) comprising an oscillator (221) and an identical thermally-sensitive crystal (222) for driving the oscillator. Each option module includes receptacles (207a-d) for the contact pins. The receptacles are connected to the digital input port of a D/A converter (225) whose output port is connected to a heater (224) mounted in physical proximity to the crystal in the crystal's case (223). Depending on which slot an option module is mounted in, the D/A converter receives a different digital input and hence generates a different level of output.

Abstract: A method and a device for regulating the heating of a thermostatically controlled enclosure of a quartz oscillator. During a first stage, the thermostatically controlled enclosure is exposed to an external temperature close to the maximum operating temperature and the frequency of the oscillator is measured. During a second stage, the thermostatically controlled enclosure is exposed to an external temperature close to the minimum temperature of the range and the difference between the frequency of the oscillator and the frequency previously measured is cancelled out by modifying the distribution of the powers dissipated by the heating elements of the thermostatically controlled enclosure. The heating of the enclosure is performed by a chain of voltage stabilizer semiconductor circuits connected in series, each of the circuits being traversed by a regulated heating current. The regulating of the heating action is performed by modifying the stabilized voltages of the circuits.

Abstract: An assembly for a quartz crystal oscillator housed within a can is set forth in which the oven assembly for the crystal is partially formed with metallized circuit boards to which the components for the electrical circuits for controlling the crystal oscillator are connected. A control transistor is directly mounted to one wall of the oven to further provide the major source of heat for the oven while reducing consumption of power.

Abstract: Between insulative layers (31-37, 41-44), a multilayer substrate comprises at least one dielectric layer (26-29). It is possible to form capacitors (58), resistors (46), and wiring conductors (61, 62) in the substrate. The at least one dielectric layer should be of at least one dielectric composition which has a perovskite structure. Preferably, each insulative layer is of an insulating material which consists essentially of aluminum oxide and lead borosilicate glass. The substrate is convenient in manufacturing a crystal oscillator by mounting a crystal vibrator (71) and a transistor (72) on the principal surface(s). Examples of the dielectric composition are:Pb[(Fe.sub.2/3.W.sub.1/3).sub.0.33 (Fe.sub.1/2.Nb.sub.1/2).sub.0.67 ]O.sub.3,Pb[(Mn.sub.1/3.Nb.sub.2/3).sub.0.01 (Mg.sub.1/2.W.sub.1/2).sub.0.30 (Ni.sub.1/3.Nb.sub.2/3).sub.0.49 Ti.sub.0.20 ]O.sub.3,andPb[(Mg.sub.1/2.W.sub.1/2).sub.0.66 Ti.sub.0.34 ]O.sub.3.

Abstract: The aging rate of an oscillator is minimized by applying a high drive current to the resonator early in the oscillators life until the aging rate decreases to a low value and then applying a low drive current to the resonator for the rest of the oscillators life at a constant temperature.

Abstract: A highly stable voltage variable crystal controlled oscillator adapted for stand-alone use or for use with an atomic clock for further stabilizing the oscillator. A novel Colpitts crystal oscillator configuration is employed and utilizes an FET amplifier and bipolar emitter follower configured for power gain without phase shift in the feedback circuit. The oscillator output signal is derived through the crystal which then acts as its own low pass filter to improve the purity of the output signal. A novel buffer/amplifier circuit including a grounded gate FET amplifier and coupling transformer assure frequency stability despite wide ranging load impedance variations. A resilient thermal foam material is used to enclose the temperature and shock sensitive components of the oscillator to provide further frequency stability and rugged construction.

Abstract: Temperature stability is quickly achieved for a crystal oscillator mounted in a warm-up crystal oven because the heat is applied proportionally to the mass of the oscillator and circuitry during the initial warm-up period of time and then applied proportionally to the area that will allow compensation for thermal loss after the warm-up period. The oscillator crystal is encapsulated within a case along with an oscillator circuit for the oscillator crystal that is thermally mounted to the case. A controlled heater heats the warm-up crystal oven and crystal oscillator. The controlled heater is controlled by a temperature controller that responds to a first thermal sensor that senses the temperature of the case and a second thermal sensor that senses the temperature of the controlled heater.

Abstract: A piezo-electric crystal vibrating in several modes controls several frequencies generated by voltage controlled oscillators simultaneously. The output of each voltage controlled oscillator is fed to a summing amplifier which drives the crystal. The output of the crystal is fed to individual phase detectors; each phase detector is also supplied with the output of a voltage controlled oscillator and generates a voltage proportional to the phase difference between the voltage controlled oscillator and the crystal output for correcting the output frequency of each oscillator.

Abstract: An input signal, whose frequency is to be detected, is divided and sent i two arms. One arm applies a set phase and amplitude adjustment while the other arm has a phase response that is dependent upon the frequency. Both arms are fed to a phase detector whose output is used to indicate the frequency of the input.

Abstract: A two reference cavity structure for tracking the frequency of a high power liquid cooled cavity structure, consisting of two low power cavities tuned to frequencies slightly above and slightly below the resonant frequency of the high power structure. Each of the cavities has a first and a second section, with the first sections maintained at a first temperature and the second sections maintained at a second temperature such that the reference cavities track the frequency shifts in the high power structure caused by temperature differentials between regions of that high power structure. The first section of each reference cavity may have a cylindrical outer wall and a first end wall whose temperature is governed by the temperature of the liquid coolant before it enters the high power structure.