Abstract: A voltage controlled oscillator includes an inverting amplifier connected to a resonant feedback network and a comparator for comparing the input to the inverting amplifier to a reference voltage which is equal to the threshold voltage of the inverting amplifier. As a result, the oscillator provides a square wave output having a precise one-to-one duty cycle. In addition, circuitry is included for causing the oscillator to start up at a steady state value and predetermined phase.

Abstract: A band reflection type oscillator includes a GaAs-FET having a source, a gate and a drain in which the drain is connected to ground. A stripline is connected to the gate, and a dielectric resonator is provided adjacent the stripline in a magnetically coupled relationship therewith. A stripline stub is electrically connected to the drain and positioned adjacent the resonator in a magnetically coupled relationship therewith, thereby defining a positive feedback circuit through the drain, said stripline stub, the resonator and the stripline to the gate. By the positive feedback circuit, the oscillation stability is improved.

Abstract: A dielectric resonator microwave oscillator in which the gate of a FET is connected to a resonance circuit. An inductor is connected to the drain of the FET, and the output is taken from the source of the FET. This dielectric resonator microwave oscillator has enhanced negative resistance and positively starts the oscillation even when there is a low reflection coefficient of the resonance circuit. Using a circuit which consists of a capacitor and inductor between the source and the output terminal, a further increasing of negative resistance at the gate of the FET is obtained.

Abstract: A voltage controlled oscillator (VCO) has an LC tank circuit which is pumped by two out-of-phase feedback components. The combined effect of the two out-of-phase feedback components results in an effective feedback signal that is a function of the ratio of the magnitude of the two out-of-phase coponents. The magnitude of one of these feedback components is controlled by a CMOS subthreshold Gilbert multiplier. The frequency of oscillation of an oscillating signal within the LC tank circuit changes according to a control voltage applied to the Gilbert multiplier.

Abstract: A dual gate field effect transistor (FET) is configured as a self-buffering local oscillator of a tuner by arranging the FET in a cascode configuration in which the first gate electrode is coupled to the source electrode through an oscillation conditioning network and also to a frequency determining network, the second gate electrode is coupled to signal ground through a negligible impedance and the drain electrode is utilized as the output of the oscillator.

Abstract: A microwave frequency oscillator capable of being linearly swept over a wide frequency range around a central frequency comprising a field-effect transistor with a high gain, the output of which is fed back to the input from a coupler consisting of two relatively narrow striplines located close together. A wobbulator circuit is fitted in shunt to the feedback network comprises two voltage variable capacitors in series between three line components designed to optimize the frequency modulation linearity in relation to the voltage variable capacitance diode control voltage. The oscillator is useful in equipment requiring extreme linearity such as radio-altimeter sources.

Abstract: A microwave oscillator provides two outputs, of opposite phase, which are directly connected to provide the local oscillator inputs to a balanced mixer. Since no balun is used, very wide-band performance can be obtained.

Abstract: An oscillator with a dielectric resonator capable of providing a designated output and being suited for mass production comprising an insulating substrate, a strip structure, a dielectric resonator located adjacent to the strip structure, the last two being mounted on the substrate, and an oscillatory transistor connected to one end of the strip structure. The strip structure consists of two spaced strip sections interconnected by an electrically-conductive bridge-shaped connector section having a conductor part, which is located further away from the insulating substrate and closer to the dielectric resonator than the two strip sections.

Abstract: A broadband high frequency power oscillator employing a GaAs FET transistor and a two-port coupling network whose input port is connected across the drain and source terminals of the GaAs FET. The coupling network consists of 3 branches in T- or .pi.-configuration. One branch includes a matching network and the load. The other two branches are purely reactive and each includes at least one independently tunable reactance element, such as a varactor.

Abstract: A switchable multi-frequency dielectric resonator oscillator that generates microwave energy at any of several available frequencies is disclosed. The oscillator includes a transistor that is operable for oscillation at a frequency determined by a feedback resonator connected to its control terminal, and switching means for selectively connecting any one of a plurality of feedback resonators to the control terminal of the transistor. The oscillation frequency of the oscillator is determined by the resonant frequency of whichever of the feedback resonators is connected to the control terminal of the transistor through the switching means. It is preferred to utilize dielectric resonators as the feedback resonators, a field effect transistor as the transistor, and PIN diodes as the switching means.

Abstract: A microwave frequency divider circuit. The frequency divider comprises a nonlinear amplifier including input and output ports for amplifying signals applied to the input port. The amplifier exhibits a nonlinear transconductance characteristic between its input and output ports. The amplifier input port is adaptable to receive a first signal having a frequency f.sub.l. The frequency divider further includes a feedback network coupled between the amplifier output and input ports to couple a second signal having a frequency f.sub.o appearing at the amplifier output port back to the input port. The first and second signals combine at the amplifier input port to modulate the nonlinear transconductance of the amplifier such that said first and second signals are mixed together and amplified. The circuit regeneratively oscillates such that the frequency f.sub.o equals a frequency f.sub.l /2. The frequency f.sub.l of the first signal is thus divided by the circuit.

Abstract: A very high frequency oscillator (4-22 GHz) including field effect transistor and first and second YIG sphere resonators whose reactant frequencies are displaced, which gives the oscillator a wide frequency range. The first YIG sphere is doubly coupled to the source and gate of the transistor, which gives the oscillator good linearity (.perspectiveto.10.sup.-3) over its frequency range. The second YIG sphere is coupled to the gate by a coupling wire which also couples to the first YIG sphere.

Abstract: An FET oscillator wherein a bias circuit is connected to a drain of a field-effect transistor and a source circuit including a transmission line and a self-bias circuit is connected to a source of the transistor, so that the source is substantially open-circuited at an oscillation frequency and the field-effect transistor operates as a two-terminal (the gate and drain) element exhibiting a negative resistance, and wherein a resonant circuit is connected to the gate of the transistor. With the source circuit connected to the transistor source, the oscillator can have a high unloaded Q-value of Qo and a high externally-loaded Q-value of Q.sub.ext, whereby the oscillation frequency is stable. According to this oscillator, only a single bias circuit for the drain is required without the need of a bias circuit for the gate.

Abstract: A method and means for reducing noise in a GaAs FET oscillator circuit is described. The circuit of the present invention achieves low noise oscillator operation by driving the gate input of the GaAs FET oscillator circuit with a source of voltage which exhibits a low impedance at baseband frequencies and driving the drain input with a source of current which exhibits a high impedance at said frequencies. The present invention further operates to control the D.C. voltage present on the drain terminal of the GaAs FET device regardless of the drain current, while simultaneously maintaining a constant D.C. drain current at some predetermined value which corresponds to optimum low-noise operation.

Abstract: A solid state oscillator circuit for operation at very high frequencies includes a field effect transistor having an input network connected between its gate and source electrodes and an output network connected between its drain and source electrodes, the input and output networks each including three discrete capacitors connected in a "pi" configuration, the input and output networks being connected in series with one another, and an inductor being connected in parallel with the series connected networks, the equivalent circuit impedance of the networks in series and the inductance determining the operating frequency of the oscillator circuit, and the relative ratio of impedance of the networks determining the amount of oscillator feedback.

Abstract: An oscillator circuit operable in different modes. The oscillator circuit, when operated as a crystal oscillator, is initially operated as a standard inverter oscillator requiring a low start-up voltage. Once the circuit oscillates, an hysteresis feedback network is inserted in the amplifying section of the oscillator providing a clock signal with sharper leading and falling edges. The circuit thus enables the start up of the oscillator at low voltages and ensures greater noise immunity following start-up. The oscillator circuit, when operated as an RC oscillator, may be operated as a Schmitt-trigger oscillator as soon as the oscillator is turned-on.

Abstract: A voltage controlled oscillator is disclosed wherein a peak detector is used to control the gain of the active device within the oscillator in response to a control signal taken from the resonant circuit. The control signal is a RF potential developed across a voltage divider within the resonant circuit. By controlling the gain of the active device from an RF voltage provided by a voltage divider, the RF output level of the oscillator "tracks" the DC bias level of the steering line. Therefore, varactor diodes rectification is prevented while contemporaniously allowing maximized output power.

Abstract: An oscillator-mixer arrangement including a dual-gate field effect transistor of the Schottky type for supplying an intermediate frequency output signal. The output signal is obtained by subtractively mixing a high frequency input signal and a signal produced in the arrangement. The input signal is applied to the first gate electrode (G.sub.1), the produced signal is controlled by the second gate electrode (G.sub.2), and the output signal is recovered at the drain electrode (D), while the source electrode (S) is directly connected to ground. A micro-strip line having a characteristic impedance Z.sub.O which is electromagnetically coupled to a dielectric resonator and loaded by an impedance (Z.sub.O) is connected to the second gate electrode (G.sub.2). The arrangement is intended to be included in a receiver front end assembly for very high frequency waves, typically of a frequency of 12 GHz, used for broadcasting radio-television programs by artificial satellites.

Abstract: Energy source of a low power high frequency oscillator section driving a high power high gain amplifier section. The amplifier section includes one or more SIT's. The dc operating potential is applied to the drain electrode of one of the SIT's and is supplied to the other through a dc path from the source electrode of the one SIT to the drain electrode of the other. Operating potential from the dc biasing network between the source and gate electrode of an SIT in the amplifier section is conducted through a dc path to a transistor in the oscillator section to provide operating power for the oscillator section. The oscillator output is connected through a high frequency coupling dc blocking path to the amplifier input to provide a drive signal to be amplified and extracted at the amplifier output.

Abstract: A circuit is described in combination with a dielectric-resonator-stabilized oscillator operating at microwave frequencies in which a PIN diode serves to shunt the reflected output signal of the stabilizing resonator from the input of the oscillator circuit into a load to turn the oscillator off. By biasing the diode in a reverse or forward direction, the oscillator is made to start or stop oscillating, respectively. This has the effect of switching the output of the oscillator on and off while eliminating thermal transients associated with de-energizing the active element of the oscillator circuit itself, or the necessity for inefficient microwave switches which may pass some signal through.

Abstract: A temperature stabilizing circuit for a microwave oscillator employing a field effect transistor on an AsGa substrate, in which a temperature-stabilized frequency is obtained by varying the gate-channel capacitance of an FET included in the oscillator resonance circuit. The capacitance is controlled by a voltage derived from a voltage divider comprising a series arrangement of several Schottky diodes or FET's. The circuit is suited to assembly as an integrated monolithic circuit comprising FETs on a AsGa substrate, for micro wave frequency applications such as for example, processing 12 GHz satellite television signals.

Abstract: Phase-locked loop, comprising Hartley-type oscillator being formed with a dual-gate field effect transistor (10), whose gates (G.sub.2) and (G.sub.1) constitute the phase-comparison inputs of the loop and whose drain is coupled, optionally via a low-pass loop filter (35), to the input of the feedback circuit, this feedback circuit being connected to the tuning circuit of the oscillator.

Abstract: The invention relates to an ultra-high frequency oscillator operating in the X band. The oscillator circuit comprises a common gate-connected field effect transistor. The source connected tuning circuit comprises a variable capacitor of the varactor type controlled by a voltage and a choke in parallel. The control voltage is decoupled from earth by a capacitor. According to the invention, the transistor, the varactor and the capacitor are integrated into the same box or case in the form of a micromodule. The capacitor acts as a base for the transistor and the varactor, which are welded in juxtaposed manner. The length of the connection between the varactor and the source of the transistor has a minimum value, which makes it possible to broaden the linear frequency band as a function of the control voltage.

Abstract: A power source consisting of a low power high frequency oscillator section driving a high power high gain amplifier section. The amplifier section includes one or more SIT's. The dc operating potential is applied to the drain electrode of one of the SIT's and is supplied to the other through a dc path from the source electrode of the one SIT to the drain electrode of the other. Operating potential from the dc biasing network between the gate and source electrodes of an SIT in the amplifier section is conducted through a dc path to a transistor in the oscillator section to provide operating power for the oscillator section. The oscillator output is connected through a high frequency coupling dc blocking path to the amplifier input to provide a drive signal to be amplified and extracted at the amplifier output.

Abstract: An oscillator including an active device (38), a surface acoustic wave resonator (40) connected in a feedback relationship to the active device and an impedance matching circuit is disclosed. The impedance matching circuit in one arrangement is an output impedance matching circuit including an inductor (46) connected in the feedback loop to the output of the active device. In another arrangement, the impedance matching network is an input impedance matching network including an inductor (42) connected in the feedback loop to the input of the active device. In another arrangement of the invention, a varactor diode (60) is connected in the feedback loop and is controlled by a reverse voltage which changes the capacitance of the diode, adjusting the frequency of the oscillator.

Abstract: A circuit configuration is provided for reducing noise sidebands in the output of an oscillator due to modulation of the oscillation signal by characteristic noise produced by the amplifying element. A gallium arsenide field-effect transistor that produces characteristic noise is operated as a linear amplifier. Positive feedback to the input of the amplifier is provided by a resonator. The amplitude of the oscillation signal is limited by a distinct limiting circuit in the feedback loop, the input to which is isolated from the amplifier by a high pass filter, thereby divorcing the non-linear limiting function of the oscillator from the amplifying function where noise is generated.

Abstract: An integrable bipolar oscillator circuit, includes four transistors of the same conductivity type, four resistors, three constant current sources having base points and outputs, a reference potential terminal connected to the base points of each of the constant current sources, a supply potential terminal, and a frequency-determining feedback member, the output of the first constant current source being connected to the emitter of the first transistor and to the base of the second transistor, the output of the second constant current source being connected to the emitter of the third transistor and to the base of the fourth transistor, the emitters of the second and fourth transistors being connected to the output of the third constant current source through a given connection, the collectors of the first and third transistors being directly connected to the supply potential terminal, the first and second resistors each being connected between a respective one of the collectors of the second and fourth transi

Abstract: A high frequency oscillator circuit is provided using a low cost junction type field effect transistor (T.sub.1) with a tuned circuit connected to its gate. The frequency of operation is determined by the tuned circuit and the capacitance reflected from the source to the gate. The transistor is matched to the frequency of operation so that this frequency falls within the roll-off portion of the transistor's transconductance verses frequency curve, preferably somewhat above the 3 db point in frequency. Phase shifting necessary to sustain oscillation occurs due to the operation of the transistor in the roll-off portion of the curve and the addition of a phase shifting network (R.sub.1, C.sub.1) at the source. The resulting oscillator is small, stable, linear and inexpensive.

Abstract: An FET oscillator wherein a bias circuit is connected to a drain of a field-effect transistor and a source circuit including a transmission line and a self-bias circuit is connected to a source of the transistor, so that the source is substantially open-circuited at an oscillation frequency and the field-effect transistor operates as a two-terminal (the gate and drain) element exhibiting a negative resistance, and wherein a resonant circuit is connected to the gate of the transistor. With the source circuit connected to the transistor source, the oscillator can have a high unloaded Q-value of Qo and a high externally-loaded Q-value of Q.sub.ext, whereby the oscillation frequency is stable. According to this oscillator, only a single bias circuit for the drain is required without the need of a bias circuit for the gate.

Abstract: An oscillator with inverter and delay stages is coupled between first and second reference terminals. In one aspect a depletion transistor is connected between a power supply terminal and the first reference terminal to provide a reference voltage thereat. In another aspect the delay stages each have a control terminal for controlling the delay thereof. A temperature compensation circuit has a control transistor which provides a voltage to the control terminals of the delay stages which is inversely proportional to the threshold voltage of the control transistor.

Abstract: A transistorized microwave oscillator comprising a resonator 2 coupled to a transistor 4, 5 and a feedback capacitor 7' around the transistor which produces a fundamental oscillation frequency and harmonics thereof. The feedback capacitor is located within a cut-off waveguide 21 and couples oscillations into the waveguide which blocks the lower undesired frequencies.

Abstract: A power oscillator for transmitter equipment operating at hyperfrequencies such as microwave links and radar. A plurality of elementary oscillators are coupled in parallel. Each elementary oscillator comprises a field effect transistor (FET) (11) connected in the common drain configuration with a first microstrip (51) connected to its gate and a second (21) connected to its source. Adjacent gates are interconnected by first resistances (R1) and adjacent sources by second resistances (R2). The resistances serve to balance the oscillators and to suppress parasitic oscillation. The free ends of the gate microstrips (21) are interconnected to synchronize the oscillators and the free ends of the source microstrips (51) are interconnected to constitute the oscillator outlet. The FETs may be disposed in a line or in a ring.

Abstract: The invention relates to a quartz oscillator comprising two transistors to whose base terminals the collector voltage of each one of the other transistors is applied, a two-terminal network incorporating a quartz resonator being connected to the emitter of one of the transistors. The collector voltage is applied to the corresponding base via a semiconductor junction. The oscillator further includes respective emitter and collector impedances for the transistors in which the product of the emitter impedances is greater than the product of the collector impedances. When the supply voltage is sufficiently low so that the collector-base diodes of the transistors are always in the non-conducting state, the oscillator frequency is independent, to a very large degree, of saturation phenomena of the two transistors. When manufactured in integrated circuit form, only one additional exterior terminal is required for the connection of a quartz resonator.

Abstract: The gain margin of a junction FET oscillator is improved by the addition thereto of a bipolar transistor in parallel with the FET for boosting the closed loop circuit gain of the oscillator without degrading the phase noise performance of the FET. The oscillator circuit is formed by a grounded gate JFET with a feedback circuit including the internal impedance of the FET, a capacitor which couples source and drain of the FET, a capacitor which couples the FET source to ground, and a resonant circuit coupled between the drain of the FET and ground including a varactor diode for controlling the oscillating frequency and providing a circuit output. A bipolar transistor is coupled in parallel with the FET by coupling its collector to FET's drain and its emitter to the FET's source. The base of the transistor is coupled via a by-pass capacitor to circuit ground.

Abstract: In a compensated VCO circuit arrangement for providing constant modulation level over a wide frequency band a VCO is disclosed having a linear VCO gain factor vs. control voltage curve over the wide frequency band of interest. A compensation network is coupled to the VCO to provide an audio output having a linear output level vs. control voltage curve. By appropriately matching the two linear curves the variation in modulation level over the frequency band of interest is substantially reduced.

Abstract: The optical injection-locking of an FET oscillator is accomplished by injecting the beat signal between two coherently mixed slave lasers, which are locked to different harmonics of a modulated master laser, into the FET oscillator to be locked. 120 GHz injection-locking beat signals are possible using this technique.

Abstract: A voltage controlled oscillator for use in a phase locked loop is provided with a first varactor circuit that responds to a control signal to set the center frequency of the oscillator, and with a second varactor circuit comprising a modulation varactor that responds to a modulation signal to cause the oscillator to produce a modulated output. The modulation sensitivity of the oscillator is made relatively constant between upper and lower center frequencies by applying a portion of the modulation signal to the first varactor circuit in addition to the control signal.

Abstract: A very simple oscillator circuit, using a FET pair with RF coupled, DC isolated gates, selectively operates at two widely separated microwave frequencies. The two FETs are DC isolated so that one of them can be pinched off (to act as a passive element) while the other remains active. Thus, for example, a two-FET push-push oscillator operating at 20 GHz can switch downband, when one FET is pinched off, to act as a fundamental mode oscillator at 121/2 GHz. The circuit is integrable. In alternative embodiments, more than two FETs are used, for switching over a wider frequency range when one or two of them is pinched off.

Abstract: An ultra-high frequency oscillator having a very high thermal stability using a transistor coupled by a microstrip-type transmission line to a dielectric resonator with a very low temperature coefficient. It incorporates a field effect or bipolar transistor and an insulating substrate metallized or formed of metal on one face forming the ground plane. The latter projects over the substrate at a point close to two microstrip lines deposited on the face of the substrate opposite to the ground plane, the transistor being welded to said projecting point of the ground plane and to the microstrip lines. The assembly forms a compact hybrid circuit.

Abstract: An FET oscillator includes means for controlling the gain of the oscillator to control its output level to thereby avoid limiting, and thus to reduce distortion of the oscillator output. A feedback loop is serially connected between the drain and gate electrodes to cause the gate direct voltage to increase negatively as drain output amplitude increases and thus reduce drain current and stabilize oscillator gain. The level of oscillation is adjustable by a potentiometer connection to the gate.

Abstract: A voltage controlled oscillator is provided with one or more varactors connected in series with the frequency determining capacitors of the oscillator. These varactors are in addition to prior art varactors, and increase the tunable range of the oscillator, and improve the frequency variation with control voltage characteristic of the oscillator.

Abstract: An adjustable frequency synthesizer primarily for use in an atomic frequency standard of the type used for stabilizing a frequency source by locking it to the hyperfine transition resonance of an atomic frequency resonator. The synthesizer is programmable by an externally applied code to provide the proper frequency, electromagnetic resonance field to the atomic frequency resonator. The synthesizer also provides a phase locked frequency modulating signal to produce the resonance deviation signal in the resonator. The broad range and fine frequency increments of the synthesizer permit accommodation of a wide range of resonance frequencies in the atomic frequency resonator to obviate resonator gas pressure and magnetic field variations which would otherwise decrease the production yield of such resonators.

Abstract: A device using a dielectric resonator with a very low temperature coefficient in a very high frequency transistor oscillator (3 to 10 GHz) so as to benefit both from the very high power available and the maximum frequency stabilization due to the resonator. In the case of a FET, the gate is connected to one end of a line coupled to a dielectric resonator at a point along the line situated at a quarter wavelength from the other end of the line, which in turn is connected through a discrete resistor to a half wavelength open circuit line. Thus, the oscillation is damped when the frequency varies from the resonant frequency of the resonator.

Abstract: A tire pressure monitoring system includes a tuned circuit with a pressure sensitive switch which is closed when the tire pressure is normal, connected across it, the tuned circuit and switch being mounted on the vehicle wheel. Mounted on a part of the vehicle is a detector circuit including an oscillator which includes an inductor which is at least intermittently coupled to the inductor of the tuned circuit. When the switch is closed the oscillator runs normally and its output is detected to indicate that all is well. When switch is open, however, the oscillator output is suppressed whenever the inductors are coupled together. The circuit can also be used in other applications where it is required to detect the state of an isolated switch.

Abstract: A frequency stabilizing device for a FET high-frequency oscillator comprises means for coupling an automatic biasing circuit included in the source-ground connection of the oscillator to a drain voltage supply circuit included in the drain-ground connection of the oscillator to provide simultaneous and oppositely directed variations of the resistance of the automatic biasing circuit and of the value of the drain-ground voltage supplied by the drain voltage supply circuit. A variation of this device can serve as a modulation stage wherein the coupling means comprise a modulating circuit arranged to supply two branches in parallel, each branch comprising a series arrangement of a shaping circuit and an impedance-matching circuit and one of which constitutes the automatic biasing circuit and the other one the drain voltage supply circuit.

Abstract: An oscillator of the "three-terminal" type, comprising for example a field effect transistor, having a narrow spectrum and electronically tunable within a very wide frequency band in spite of its narrow spectrum due to a resonator of the yttrium garnet ball type. The field effect transistor has its source connected to a dipole comprising an electronically variable reactance and its gate connected to a similar dipole. A feedback loop is also established between input and output circuits of the oscillator. Under the action of a single command, acting for example on a magnetic field, the reactances vary simultaneously. In one embodiment, a single yttrium garnet ball resonator has two conductive half loops inserted in the tuning dipole and coupling dipole of the oscillator.

Abstract: A power oscillator utilizing one or more field effect transistors in conjunction with a tank circuit.

Abstract: First and second field effect transistors (FETs) each have a gallium arsenide substrate with an N-type active region that carries first and second electrodes in ohmic contact therewith and a gate electrode. The FETs are mounted in a flip-chip carrier that connects the first electrodes to ground. The FETs are biased to cause a current to flow from the first to second electrodes, whereby the first and second electrodes serve as drains and sources, respectively, of the FETs. The gate of the first FET is connected to a resonator. Additionally, a matching network connects the source of the first FET to the gate of the second FET. The matching network and the biasing of the first FET cause the gate input impedance thereof to be of a negative value that compensates for losses in the resonator. A load connected to the source of the second FET and the bias voltage cause the second FET to have a gate input impedance of a negative value that causes oscillation.

Abstract: An N-channel MOS monolythic R.F. Modulator for use in television games or the like is provided which internally generates an R.F. carrier signal and modulates same in accordance with the composite video output signal from the T.V. interface chip. The modulator utilizes two depletion mode MOSFETs connected in a cascode configuration, the output circuits of which are connected in series with an inductor, between a voltage source and ground. The input terminal of one of the transistors receives the composite video signal. The input terminal of the second transistor is connected to a resonant frequency circuit. The resonant frequency circuit is electromagnetically coupled to the inductor such that the current flowing through the inductor impresses a current in the resonant frequency circuit to cause same to generate the R.F. carrier signal.