Abstract: A current type inverter circuit used in a Current Type Ring Oscillator and a Voltage-Controlled oscillator operates at a high speed with a low power consumption. A reference power source 1 has one end connected to a power source VDD and the other source receiving a reference current Iref. A drain and a gate of an NMOS transistor Q1 of a current mirror circuit CM1, as an input part, receive an input current Iin. A drain of an NMOS transistor Q2 is connected to an node N1 of the other end side of the reference power source 1 as an output part. As an input part, a drain and a gate of an NMOS transistor Q3 of a current mirror circuit CM2 are connected to the node N1 while a drain of an NMOS transistor Q4 functions as an output part for outputting an output current Iout. The transistors are set so that all of the conditions TS1.gtoreq.1, TS2.gtoreq.1 and TS1.multidot.

Abstract: A quadrature oscillator includes an amplitude control circuit that is based upon the trigonometric identity sin.sup.2 .omega.t+cos.sup.2 .omega.t=1. The amplitude control circuit, referred to as a Pythagorator, includes two squaring circuits. Each squaring circuit receives a respective quadrature oscillator signal and squares it. The outputs of the two squaring circuits are joined together so as to sum the outputs of the two squaring circuits to produce a sum of squares signal. This signal, a current in the preferred embodiment, is provided to damping diodes coupled to the outputs of the quadrature oscillator. The damping diodes produce a shunt positive resistance at the outputs of the quadrature oscillator in response to this current that has the effect of cancelling the shunt negative resistance of the regenerative elements of the oscillator thereby establishing the amplitude of the quadrature oscillator signals at a desired amplitude.

Abstract: An oscillation circuit is provided which is easily adjusted with a high degree of accuracy. The oscillation circuit including a filter having a time constant and an inverting amplifier which feeds back the output of the filter to the input side of the filter so that an oscillation condition is fulfilled. The filter includes a gm amplifier formed of a differential amplifier, and a capacitor. The constant current source of the differential amplifier is connected to a free running oscillation frequency adjusting circuit. The adjusting circuit includes a microcomputer, a decoder which decodes the output data of the microcomputer and a switching circuit driven by the output of the decoder and varying the current value according to the output of the decoder. A current in accordance with a current value depending on the setting of the switch flows through the constant current source.

Abstract: An oscillating signal generator for generating an oscillating signal having a variable oscillation frequency that can be near the unity gain frequency of the gain devices within the oscillating signal generator (Generation of High-Frequency Oscillating Signal Techniques, "GHOST"). Two gain stages, each with a respective effective resistance R.sub.eff, an emitter load capacitance C.sub.E, and a respective gain device having a unity gain frequency .omega..sub.T, are cascaded and configured to provide a respective gain with a phase at substantially 180.degree.. In that case, the oscillation frequency, of the oscillating signal generated by the oscillating signal generator of the present invention, .omega.=?.omega..sub.T /(R.sub.eff C.sub.E)!.sup.1/2. A feedback with a feedback gain is provided between the output to the input of the cascade of the two gain stages. The feedback gain is designed such that a product of the feedback gain and the gain through the cascade of the two gain stages is substantially one.

Abstract: A voltage controlled ring oscillator having a reduced voltage controlled oscillator (VCO) gain by controlling only the fall time of the period of the VCO using integrated circuits and logic circuits. The VCO includes a mixer/inverter circuit, a logic circuit, a delay/inverter circuit, a first delay circuit, a second delay circuit, and a third delay circuit. The VCO gain is reduced by controlling only one pulse width of the logic level High and one pulse width of the logic level Low of the oscillating period. Furthermore, the VCO can be logically controlled by using a simple logic circuit as a component of the VCO.

Abstract: A monolithically integrated oscillator is implemented as ring oscillator with a line driver and a double line formed on one and the same chip. A running time of the double line is selected optimally long and a delay time of the line driver is selected optimally short. The double line can be loaded with controllable capacitors.

Abstract: A microwave differential amplifier comprises a first and a second matched NMOS device, each connected with the source to a common bias node, the gate to an input port for receiving a differential input signal and with the drains to an output port for providing a differential output signal. The Miller capacitors of each device provide the necessary feedback between the input and output ports for shifting the phase of the differential output signal with respect to the phase of the differential input signal with 45.degree. at a predetermined frequency. The operating point of the NMOS devices is maintained in the linear region of the respective transfer characteristic, using matched loads and a corresponding bias current. The loads may be resistors, in which case AGC is used for maintaining a constant bias current, or active loads. A VCO built with four such differential amplifiers in a gyrator configuration oscillates at the predetermined frequency and has eight output signals.

Abstract: A monolithic CMOS phase-lock loop (PLL) circuit provides a high frequency of operation suitable for RF applications. The PLL produces an output clock with high spectral purity and very low jitter. The output clock has a low static phase error relative to a reference input, making the PLL also useful for clock synchronizing applications, such as clock recovery elements in transmission/recycling channels. The PLL provides in-phase and quadrature signals from a VCO which has two differential transconductor stages having negative output conductance.

Abstract: Both differential and single-ended band-switchable VCOs are described. The single-ended version of the voltage controlled oscillator in its most basic form includes a load, two transistors, two delay elements, and a switchable current source. The first transistor includes a collector, an emitter and a base coupled to the load to form an output terminal for providing an oscillator output signal. The first delay element is connected between the collector and the base of the first transistor. The second transistor includes a collector, an emitter and a base connected to the base of the first transistor. The second delay element is connected between the collector of the first transistor and the collector of the second transistor.

Abstract: Multiple resonator stages are connected in series to form a closed loop. Each of these cascaded resonator stages includes at least a high frequency resonator and an amplifier. The amplifier amplifies the output of the high frequency resonator. Each stage also includes a power divider connected to the amplifier output. The power divider has at least two outputs. One of the two power divider outputs serves as an output of the oscillator formed by the cascaded resonator stages. The other output of the power divider is connected to the input of the next high frequency resonator stage. The oscillator further includes a phase shifter connected between two of the high frequency resonator stages to achieve a closed loop phase shift of N(360) degrees at the oscillator operating frequency, where N is an integer. The high frequency resonators may be acoustic resonators such as surface acoustic wave resonators (SAWR).

Abstract: The output frequency (14) of an oscillator circuit (10) can be controlled by replacing at least one of the reactive components (40), such as a capacitor or inductor, with a synthesized element (22). The synthesized element creates a signal that corresponds to the response of the reactive component it is replacing. The synthesized element may be a current source (44), such as a field effect transistor, that is capable of operating at low voltages.

Abstract: A voltage controlled oscillator that completely eliminates the need for any externally mounted coil and capacitor includes a first loop and a second loop. The first loop provides band-limiting of an output signal of an amplifier through a bandpass filter to provide oscillation at a frequency of a resonant point of the bandpass filter, and the second loop controls the oscillation amplitude, so that a lowpass filter output with a 90.degree. phase is extracted from the first loop, while a bandpass filter output with a 0.degree. phase is extracted from the second loop. The voltage controlled oscillator may be used in an automatic fine tuning circuit for television.

Abstract: A current controlled variable frequency oscillator (260) operates at a characteristic frequency that is determined primarily by a scaled current. A filter cascade (320) receives the scaled current for setting a filter cascade frequency substantially equal to the characteristic frequency. Additionally, the filter cascade (320) receives a triangular signal at a non-inverting input, the filter cascade (320) converting the triangular signal into a sinewave signal. A lowpass filter (330) receives the scaled current for setting a lowpass filter frequency to a frequency substantially less than the characteristic frequency. The lowpass filter (330) also receives the sinewave signal and provides an average signal therefrom. A comparator (340) receives the scaled current, wherein the comparator (340) compares the sinewave signal and the average signal for providing a substantially squarewave signal therefrom.

Abstract: An oscillator including two gm/C stages is disclosed. Each gm/C stage includes a differential pair of transistors, a capacitor, and a tunable current source. Alternatively, multi-tanh n-tuplets can be used in place of the differential pairs in the gm/C stages to increase the linearity of the gm/C stage. The gm/C stages include a pair of input terminals, a pair of output terminals, and a pair of common-mode terminals. The two gm/C stages are interconnected in a feedback loop to form a quadrature oscillator. A common-mode biasing circuit is coupled a supply voltage and each pair of common-mode terminals for biasing the respective gm/C stage. The common-mode biasing circuits can include: current mirrors, diode pairs, and even resistors. An optional start-up circuit can be coupled to each gm/C stage to ensure start-up of the associated gm/C stage.

Abstract: An oscillator circuit including a current-controlled phase shift circuit and a feedback circuit including a quartz resonator is capable of varying the oscillation frequency in accordance with control current signals. A phase shift circuit included in the current-controlled phase shift circuit includes a first low-pass filter including a resistor and a capacitor, a first buffer amplifier, a second low-pass filter including a resistor and a capacitor, and a second buffer amplifier. The phase shift circuit has a significant gain at any frequency for oscillation. Especially an oscillation circuit implemented by an integrated circuit satisfies the suitable condition in which relative value of resistances and capacitances do not vary.

Abstract: This invention relates to oscillators employing a primary feedback network and a high pass filter feedback network. The feedback networks are connected between the input and output of a of a high signal gain amplifier system. The primary feedback network provides positive feedback to cause oscillation to occur and also determines the nominal frequency of oscillation. The high pass filter feedback network provides a negative feedback signal that controls the rise and fall time of the amplifier system's output signal. By varying the output signal's rise and fall time the frequency of oscillation is also changed. The high signal gain amplifier system operates with one or more amplifier stages in the non-linear region to produce a significantly distorted sine wave or pulse output signal.

Abstract: A ring oscillator giving oscillation with a high, stable Q value. The ring oscillator is constituted by gain-stages connected by lowpass filters consisting of a resistance element and a capacitive element connected in series and is provided with transconductance circuits including transistors parallel to the capacitive elements of the lowpass filters. By passing currents proportional to signal voltages differing .theta. in phase, it is possible to operate the low pass filters as bandpass filters. By this, oscillation with a high, stable Q value is obtained. The ring oscillator can be modified to a voltage controlled oscillator by using variable current sources.

Abstract: A variable frequency digital ring oscillator which can be formed in a small area for use in testing of chips employs a ring oscillator formed of CMOS inverters, transmission gates and capacitors and CMOS logic as a voltage controlled ring oscillator. A wide range of frequency of oscillation is achieved with small number of components. The ring oscillator circuit's oscillator frequency is controlled only by DC voltages, such as may be provided by (but not limited to) a manufacturing chip tester. The output signal of the oscillator swings between Vdd and Vss and does not need additional level translation circuits to drive CMOS logic. The ring oscillator can be composed of an odd number of CMOS inverters connected in cascade to form a loop. We provide a CMOS transmission gate with PMOS and NMOS transistor device inserted between each adjacent inverter and a MOS capacitor connected between the output of each transmission gate and the Vss supply of the ring oscillator circuit (conventionally ground).

Abstract: A voltage controlled surface acoustic wave oscillator includes an integrated circuit and a two port resonator connected as a feedback element around the integrated circuit. The integrated circuit includes a phase shifting network and an amplifier directly connected to the phase shifting network.

Abstract: A FET oscillator with increased frequency stability. This is accomplished by using a controlled voltage supply to power the amplifier stage of the oscillator. This voltage changes as the FET amplifier temperature increases in order to reduce the variation in frequency, caused by the amplifier's gain and phase shift changes. By using this compensated amplifier as the active section of an oscillator, the oscillator frequency stability is increased.

Abstract: A single frequency oscillator (10) comprises a laser diode (12), a fibre optic bundle (22) acting as a delay line filter, a photodiode (26) and a feedback loop to the laser diode (12) containing an amplifier (28) and additional low Q filtering (29, 34). The laser diode output (18) bears a modulation signal which is filtered to a series of "resonant" or synchronous frequencies by the bundle (22), converted back to an electrical signal by the diode (26) amplified, and reduced to a single resonant frequency by the low Q filtering (29, 34). It is then applied to the laser diode (12) as positive feedback to modulate the diode output (18). The output of the oscillator (10) can be taken as a microwave signal or on an optical carrier. The invention provides an oscillator incorporating feedback on an optical carrier.

Abstract: An apparatus is disclosed for generating an output signal in response to an input signal having a variable input level. The output signal has an output frequency which varies to represent variations in the input level. The apparatus comprises a processing circuit for implementing a digital signal processing algorithm to generate control signals in response to the input signal, which control signals are representative of the variable input level, and an oscillator circuit for generating the output signal in response to the control signals. The control signals include a first control signal representing a first output frequency, a second control signal representing a second output frequency, and at least one intermediate control signal representing output frequencies intermediate the first and second output frequencies.

Abstract: A coupled resonator filter oscillator having an impedance matching network coupled between an amplifier and a filter. The impedance value of the amplifier varies due to amplifier gain compression. The network maintains a constant impedance to the filter when said amplifier's impedance changes to preserve the filter's original transfer function.

Abstract: An RC oscillator for varying an oscillation frequency which has a counter for counting a clock pulse of the oscillation frequency and for outputting a counted value in a form of a plurality of bits to an output terminal. It also includes a standard capacitor, a plurality of capacitors having a capacitance value in proportion to a weight of bits outputted from the counter, and a plurality of switches connected to one end of each capacitor for selectively connecting the capacitors in parallel. A plurality of first gate circuits control the switches connected thereto in response to an output of the counter, each first gate circuit has an input terminal connected to an output terminal of the counter and an output terminal connected to a control terminal of the switches.

Abstract: A resonant circuit comprises first and second amplifiers. An input of the second amplifier is coupled to an output of the first amplifier, and an output of the second amplifier is cross-coupled to an input of the first amplifier. The first amplifier has a first gain and a 90 degree phase shift between its input and its output at a resonant frequency of the resonant circuit. The second amplifier has a second gain and a 90 degree phase shift between its input and its output at the resonant frequency of the resonant circuit. The second gain is different from the first gain. The resonant circuit can have a first port and second ports coupled to an input and an output respectively of one of the first and second amplifiers. Because the gains of the first and second amplifiers differ, the gain from the first port to the second port of the resonant circuit will differ from the gain from the second port to the first port.

Abstract: Monitoring of the average dielectric constant in an extended volume of a medium such as soil is achieved using an oscillator incorporating a transmission line to be embedded in the medium. The transmission line is connected as the feedback loop of an amplifier, for one-way propagation of an electrical signal with a delay determined largely by the dielectric properties of the medium, such as its moisture content. The oscillation frequency is indicative of the dielectric constant of the medium.

Abstract: An improved oscillator circuit and method for measuring capacitance and small changes in capacitance is described. The circuit provides a digital output signal that has a frequency inversely proportional to the capacitance being measured, is substantially immune to stray capacitance, has low sensitivity to noise and temperature variations, is relatively simple and inexpensive to implement and provides a high precision measurement. One embodiment of the oscillator includes a capacitor to be measured, an integrator, an inverting amplifier, a comparator, a summing amplifier and a digital output circuit. A second embodiment of the oscillator further provides compensation for the non-linear response of a parallel plate capacitive transducer.

Abstract: An improved oscillator circuit and method for measuring capacitance and small changes in capacitance is described. The circuit provides a digital output signal that has a frequency inversely proportional to the capacitance being measured, is substantially immune to stray capacitance, has low sensitivity to noise and temperature variations, is relatively simple and inexpensive to implement and provides a high precision measurement. One embodiment of the oscillator includes a capacitor to be measured, an integrator, a comparator, a resistive attenuator, a summing amplifier and a digital output circuit. A second embodiment of the oscillator further provides compensation for the non-linear response of a parallel plate capacitive transducer.

Abstract: Controllable oscillator circuit comprising a regenerative loop which incorporates a cascade circuit of first and second sections each having a controllable gain and a phase shift which is 90.degree. at the oscillation frequency, and an amplitude detection arrangement which is coupled between an output and a control input of at least one of the two sections.

Abstract: A clamped linear transconductance amplifier path, consisting essentially of a current clamp merged in a linear transconductance amplifier path, is used in a triple-input, triple-output transconductor (200). In a balanced transconductor in CMOS technology, this clamped linear transconductance amplifier path is formed by a p-channel MOS transistor (M23) separately connected in series with each of a matched pair of p-channel MOS transistors (M21,M22). The clamped linear transconductance amplifier path, together with two other transconductance paths (M15-M20; M9-M14), can be interconnected to form the input side of the triple-input, triple-output transconductor (200). By summing and integrating the outputs of the input side of the triple-input transconductor (200), the output (V.sub.OUT,P and V.sub.OUT,N) of the output side of the transconductor can be formed. By feeding back this output to the input side of the transconductor (200), an oscillator can be obtained.

Abstract: Microwave oscilltors incorporate r.f. feedback with carrier suppression to reduce phase noise. In a direct feedback oscillator arrngement a circulator is interposed between the r.f. amplifier and the high-Q resonator. The amplifier output is applied to the slightly over-coupled input port of the resonator so that the resultant net return signal is the vectorial difference between the signals emitted and reflected from the resonator. The gain of the r.f. amplifier is chosen to regenerate the forward signal from the net return signal. In a STALO-type arrangement, the resonator is critically coupled and an r.f. amplifier added to the path of the net return signal. The sensitivity of the STALO-type feedback loop is thereby enhanced while added amplifier noise is minimized by the superposition of the signals emitted by and reflected from the resonator.

Abstract: A quadrature oscillator network for simultaneously producing a sine wave and a cosine wave. The oscillator includes an integrating circuit and a time delay circuit, each of which is preferably constructed, in part, with an operational amplifier. In one example, a first output is developed from the integrating circuit and transmitted to the time delay circuit. The time delay circuit receives the first output from the integrating circuit and generates a second output. The integrating circuit and the time delay circuit are interconnected with a feedback branch which is employed to transmit the second output of the time delay circuit to an input of the integrating circuit. In the preferred form of operation, the first output is sinusoidal in form and the second output is cosinusoidal in form.

Abstract: A universal voltage-controlled multivibrator comprises a signal state conversion circuit and a feedback circuit. The signal state conversion circuit has the output states as a function of the input states. The feedback circuit, containing multiple controlling input terminals, has a propagation delay time as a function of the electrical signal applied to the controlling input terminals. One output of the signal state conversion circuit is connected to one input of the feedback circuit and the output of the feedback circuit is connected to one input of the signal state conversion circuit such that the output of the signal state conversion circuit is fed back to its input to have the period of its output signal be controllable by the signals applied to the controlling input terminals of the feedback circuit.

Abstract: A controllable quadrature oscillator, having a pair of oscillator outputs for supplying a pair of phase quadrature oscillator signals, is a cascade circuit of two quadrature sections incorporated in a regenerative loop each contributing a 90.degree. phase shift in the regenerative state of the loop. In order to increase the frequency control range of such a controllable quadrature oscillator and to enable realization by integrated circuit technology, each quadrature section is formed of two stages in cascade arranged in a signal path between an input terminal and an output terminal for the quadrature section. One of the stages includes a first amplifier having a low-pass characteristic and the other of the stages includes a second amplifier having a low-pass characteristic and having a feedback path. The gain of at least one of the two amplifiers is controllable for controlling the frequency of the pair of phase quadrature oscillator signals.

Abstract: A sinewave oscillator and a quadrature phase shift network fabricated as an integrated circuit for a Barber radio receiver comprising, in order that the network and oscillator be simply adjustable to provide an accurate 90.degree. shift and a sinewave of accurate frequency and high spectral purity, a first capacitance means (C1, C2; C4, C5) coupled to the input of a gyrator (G1; G2) comprising first and second amplifiers (10, 12; 22, 24) connected in feedback configuration with a capacitance (C3; C6) connected to the output of the first amplifier. The oscillator network may be adjusted by current control of transconductance of the amplifiers, and the amplifiers include input signal limiting means to limit the input signal to a linear operating region. An output load resistance (R) may be simulated using a further amplifier connected in feedback configuration.

Abstract: A voltage controlled oscillator (VCO) comprises the series arrangement of two signal inverters whose outputs are coupled to the input of the first signal inverter through a feedback loop, and a control circuit including a series arrangement of two diodes arranged in the same direction, whose interconnected electrodes are coupled to the input of the first inverter. The other electrodes of the diodes form inputs for two control voltages with which the frequency of the VCO can be varied over a continuous range. The VCO is used in a phase locked loop which includes a phase detector for generating an error signal representative of a phase difference between a reference signal and a signal taken from the VCO, and a loop filter for producing a control signal from the error signal. The phase detector is arranged as an EXOR gate with a first input for the reference signal voltage and a second input for the output voltage of the VCO.

Abstract: Voltage-controlled oscillator provided with a frequency-determining element and an oscillator loop having a phase-rotating network, in which the value of one or more elements depends on a control signal which is fed to a control input and with which the phase rotation and thereby the oscillator frequency can be changed. The oscillator is further provided with a phase control loop, at least comprising a phase-rotating network to the input of which the oscillator signal is fed, a phase detector to the two inputs of which the input signal and the output signal of said phase-rotating network are fed, and an amplifier which amplifies the output signal of the phase detector and feeds it to the control input of the phase-rotating network of the oscillator loop. The phase detector has an accurately known and temperature-independent input-output relation. The phase-rotating network of the phase control loop may be formed by the phase-rotating network of the oscillator loop (FIG. 2).

Abstract: A UHF-feedback oscillator for a frequency range of at least 300 MHz to 1000 MHz includes an amplifier stage, a voltage controlled tuning filter and a feedback quadripole. The feedback quadripole comprises a two- or three- loop helical waveguide resonator. Thus, the oscillator is easily adjustable to its oscillating condition within the very wideband frequency range of between 300 MHz and 1000 MHz and can be miniaturized in the simplest manner.

Abstract: A ring oscillator circuit comprises a plurality of inverter states (301, 302, 303) connected in a series loop. Each stage has a voltage input (315, 315', 315") with an associated input capacitance and input threshold voltage, and a current output (316, 316', 316"). An active output circuit regulates the output currents so as to regulate the frequency of oscillation. A single reference circuit (307) can be used by more than one stage. The output circuit can vary the output currents to compensate for variable supply voltages. The oscillator can be used as part of a bias generator in an integrated circuit.

Abstract: A phase shifter VCO has at least first and last fundamental circuits each including an amplifier adding circuit, a control input connected to all of the other control inputs for a tuning potential varying an amplification operative ratio between the first input and the output to the second input and the output of the adding circuit, a reference input for a reference potential, symmetrical first and second non-inverting and inverting circuit input pairs, a symmetrical non-inverting and inverting circuit output pair, and a symmetrical timing element having an input connected to the first circuit input and having an output forming the first input of the adding circuit. The first non-inverting input of the first fundamental circuit is connected to the non-inverting output of the last fundamental circuit, and the first inverting input of the first fundamental circuit is connected to the inverting output of the last fundamental circuit.

Abstract: A wide band tunable microwave oscillator for monolithic microwave integrated circuits. The oscillator does not use varactors or inductors for oscillation, but uses a voltage variable resistor coupled to a first MESFET supplying a capacitance, and to an amplifying element to create an RC oscillator. The voltage variable resistor is a second MESFET coupled to a variable voltage source. The oscillator takes advantage of the gate capacitance of the first MESFET, as well as the gain available from using an active element within the feedback loop.

Abstract: A simple and inexpensive crystal oscillator is provided which employs negative voltage gain, single pole response amplifiers. The amplifiers may include such configurations as gate inverters, operational amplifiers and conventional bipolar transistor amplifiers, all of which operate at a frequency which is on the roll-off portion of their gain versus frequency curve. Several amplifier feedback circuit variations are employed to set desired bias levels and to allow the oscillator to operate at the crystal's fundamental frequency or at an overtone of the fundamental frequency. The oscillator is made less expensive than comparable oscillators by employing relatively low frequency amplifiers and operating them at roll-off, at frequencies beyond which they are customarily used. Simplicity is provided because operation at roll-off eliminates components ordinarily required in similar circuits to provide sufficient phase-shift in the feedback circuitry for oscillation to occur.

Abstract: A data driven clock generator provides a clock having a minimum cycle for a computer processor that implements asynchronous operations. The clock generator includes a basic oscillator that provides a feedback signal as a first input to a logic gate. A data valid signal, which may be generated by a multiplexer having a plurality of test inputs, is provided as a second input to the logic gate. The logic gate produces a trigger signal for starting the oscillator. If an asynchronous operation is not complete by the end of the minimum clock cycle, the oscillator is halted to stretch the clock until a data valid signal is received. The feedback signal provided to the logic gate guarantees completion of a minimum clock cycle upon receipt of a data valid signal even if the data valid signal is unstable during the clock cycle.

Abstract: A voltage controlled oscillator with temperature compensation and reduced trigger jitter. The temperature compensation is improved by applying an on-chip generated temperature-dependent control voltage to first and second parallel oscillator stages through which the oscillation signal passes. The second stage has a greater signal propagation delay than the first stage. The control voltage determines the signal delay contributed by each stage to the oscillating signal, decreasing the delay in response to a temperature-induced decrease in oscillator frequency and increasing the delay in response to a temperature-induced increase in frequency. The oscillator also includes means for generating oscillations from a predetermined signal phase that is independent of the oscillator phase before triggering.

Abstract: A microwave oscillator in a loop configuration comprises three substantially identical amplifier stages each having its own phase shift at a selected oscillating frequency. A transmission delay element having a phase shift at the selected oscillating frequency, is also in the loop configuration, so that the oscillator has zero phase shift around the loop at the oscillating frequency. Each amplifier stage has at least one active component with resistive feedback, which is connected to DC blocking and filtering capacitors. Capacitor values between 2.2 and 5.1 pf are used making the oscillator design amenable to cost effective conventional hybrid and semiconductor processes.

Abstract: A DC voltage is synthesized from a combination of a plurality of N phases of an oscillator signal. A diode circuit is used to combine the N phases, and a relationship between components of the circuit is established to eliminate the Nth harmonic of the oscillator signal from the synthesized DC voltage. Provision of non-zero input series resistances for four diodes together with a non-zero summing output resistance therefor provides a DC voltage having no harmonics below the eighth harmonic for a double-integrating oscillator providing four equally displaced phases of a signal.

Abstract: A simple circuit for converting the resistance variations of a strain gauge measuring bridge into a frequency variation of an oscillator. The circuit includes first and second phase shift circuits connected in cascade in a feedback loop with a frequency-independent device having a variable gain factor F connected in parallel with the first phase shift circuit. The first phase shift circuit includes a high pass filter and a summing amplifier and the second phase shift circuit includes an all-pass filter circuit.

Abstract: An oscillator comprising a delay circuit having an input terminal and an output terminal, and a tristate inverter having an input connected to the output terminal of the delay circuit and an output connected to the input terminal of the delay circuit. This tristate inverter is adapted to be switched by a control signal between an operable condition and an inoperable condition. A wave shaping inverter is connected to the output of the tristate inverter to generate a shaped pulse signal. Further, there is provided at least one tristate inverter having an input directly connected to an output of the tristate inverter itself so that it can generate a predetermined potential corresponding to the threshold of the tristate inverter itself. This voltage generating tristate inverter is connected at its output terminal to a selected one of the input and output terminals of the delay circuit.

Abstract: A voltage controlled oscillator circuit having an amplifier coupled in series with a feedback circuit and having adjustable voltage means coupled to the phase shifting element means for varying the phase shift of the phase shifting element output signal thereby varying the frequency of oscillation of the oscillator circuit.

Abstract: An oscillator produces an output signal which is frequency locked to a reference signal but phased locked to a triggering signal. The oscillator includes a NOR gate having its output fed back to one of its inputs through a programmable delay circuit while the triggering signal is applied to another of its inputs. When enabled by the triggering signal, the output signal of the NOR gate oscillates at a frequency inversely proportional to the delay time of the delay circuit. The delay time is controlled by a control circuit which counts NOR gate output signal cycles occurring during a predetermined number of reference signal cycles and increments the delay time when the count is higher than expected for an oscillator output signal of a desired frequency and decrements the delay time when the count is lower than expected.