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Showing papers on "Voltage-controlled oscillator published in 1968"


Journal ArticleDOI
TL;DR: In this paper, an analysis of a parametric oscillator with the nonlinear crystal internal to the laser is performed using self-consistency equations as the starting point, and the equations of motion of such an oscillator are derived.
Abstract: Since the fields inside a laser cavity are much higher than the external fields, an analysis of a parametric oscillator with the nonlinear crystal internal to the laser is performed. Using self-consistency equations as the starting point, the equations of motion of such an oscillator are derived. Depending on various cavity, pumping, and nonlinearity parameters, these lead to several types of oscillation with distinctly different operating characteristics: (1) efficient parametric oscillation similar to that of previous analyses; (2) inefficient parametric oscillation resulting from the fact that the nonlinear interaction drives the phases rather than the amplitudes of the signal, idler, and pump; and (3) a pulsing output from the oscillator with repetitive pulses of the signal and idler. A stability analysis of these various regions shows that they are mutually exclusive and can be experimentally chosen by changing the laser gain, the oscillator output coupling, or the strength of the nonlinear interaction. It is shown that the internal oscillator efficiency rapidly approaches the Manley-Rowe limit, as the available pump power becomes several times greater than that required for threshold. The efficiency of an external oscillator having a triply resonant optical cavity is found to be generally less than that of the corresponding internal oscillator.

76 citations


Journal ArticleDOI
TL;DR: In this paper, a tunable optical parametric oscillator using a 5145-A argon laser as a pump and lithium niobate as the nonlinear material is reported.
Abstract: A tunable optical parametric oscillator using a 5145‐A argon laser as a pump and lithium niobate as the nonlinear material is reported. The oscillator is constructed in a manner such that the total multimode power of the pumping laser is useful for pumping the oscillator. Operation far from degenerate, combined with a relatively long crystal, leads to measured bandwidths of oscillation about ten times less than those previously reported.

71 citations



Proceedings ArticleDOI
22 Apr 1968
TL;DR: In this article, the authors surveyed the performance of existing high quality frequency multipliers and R F amplifiers which operate in the range of 5 MHz to microwave frequencies, including the passive linewidths of existing atomic frequency standards.
Abstract: The high phase stability of atomic frequency standards has called for the development of associated electronic equipment of equivalent or superior stability. We have surveyed the performance of existing high quality frequency multipliers and R F amplifiers which operate in the range of 5 MHz to microwave frequencies. We were most interested in the phase noise in the range of Fourier frequencies, f , of about Hz to l o t 3 Hz, since most electronic servo systems in existing atomic frequency standards use modulation frequencies which fall within this range. This range also includes the passive linewidths of existing atomic frequency standards.

63 citations


Journal ArticleDOI
TL;DR: In this paper, a method of oscillator design that maximizes the output power is presented, which is applicable to the class of nonlinear elements whose single frequency largesignal parameters depend on a single port voltage.
Abstract: A method of oscillator design that maximizes the output power is presented. The embedding network is derived from a set of four linear algebraic equations. The method is applicable to the class of nonlinear elements whose single frequency largesignal parameters depend on a single port voltage.

44 citations


Patent
30 Oct 1968
TL;DR: In this article, a frequency synthesizer with multiple signals having the same reference frequency, but a different phase, is provided. Each signal is used to correct the frequency of the VCO at a different time during the time interval necessary for one cycle of the reference signal to occur, thereby increasing the number of corrections without increasing the reference frequency of correction.
Abstract: In a frequency synthesizer, multiple signals having the same reference frequency, but a different phase, are provided. Each one of the reference signals is used to correct the frequency of the VCO at a different time during the time interval necessary for one cycle of the reference signal to occur, thereby increasing the number of corrections without increasing the reference frequency of correction.

40 citations


Journal ArticleDOI

38 citations


Journal ArticleDOI
TL;DR: Two methods for generating a coherent reference for the demodulation of a suppressed-carrier signal, namely, the squaring loop and the mathematically equivalent Costas loop are analyzed, including at some points the effects of VCO noise and initial frequency detuning.
Abstract: It is advantageous from power considerations to allow suppressed-carrier coherently-detected communications. Two methods for generating a coherent reference for the demodulation of a suppressed-carrier signal, namely, the squaring loop and the mathematically equivalent Costas loop, are analyzed, including at some points the effects of VCO noise and initial frequency detuning. The steady-state phase error probability distribution is presented, as is the expected time to first loss of lock in the first-order loop. Probabilities of error in coded or uncoded telemetry systems which use a squaring loop to generate a coherent subcarrier reference are investigated, allowing appropriate values of system parameters to be chosen by system designers.

27 citations


Patent
28 Oct 1968
TL;DR: In this paper, the phase discriminator is used to generate an error voltage of suitable polarity and amplitude, indicative of the lead or lag between the data and clock signals, which is applied to the voltage controlled oscillator to modify the frequency and phase of the clock.
Abstract: A phase lock oscillator includes a phase discriminator that develops an error signal by comparing a clock from a voltage controlled oscillator with incoming random data bits. In the absence of data, the phase lock oscillator is inactive. However, when data is sensed, a logic and delay network in the phase discriminator develops an error voltage of suitable polarity and amplitude, indicative of the lead or lag between the data and clock signals. The error voltage is applied to the voltage controlled oscillator to modify the frequency and phase of the clock. Furthermore, first and second integrations are provided by the phase discriminator and an integrator respectively so that the steady state phase error is held close to zero.

26 citations


Journal ArticleDOI
T.P. Lee1, R.D. Standley1, T. Misawa1
TL;DR: In this paper, a silicon impact avalanche transit-time diode oscillator and an amplifier were operated at 50 GHz with an overall efficiency of 2 percent, achieving phase-locking with a maximum normalized gain-bandwidth product of 0.1.
Abstract: Recent experimental observations on a silicon impact avalanche transit-time diode oscillator and amplifier CW-operated at 50 GHz are presented. 1) CW oscillation power of 100 mW was obtained at an overall efficiency of 2 percent. The oscillation frequency was continuously tunable over a 1.3-GHz range by a sliding short. 2) Phase-locking has been achieved with a maximum normalized gain-bandwidth product of 0.1. The minimum locking signal power required for a 500-MHz locking bandwidth was 20 dB below the oscillator output. 3) Electronic tuning of the oscillator frequency was demonstrated by placing a millimeter-wave varactor diode in the tuning circuit. The output frequency versus the bias voltage on the varactor diode was linear with maximum frequency deviation of 300 MHz. Frequency modulation of the oscillator by driving the varactor with a sinusoidal source was obtained at a modulation frequency of 50 MHz. 4) Stable amplification with 13-dB gain was obtained, centered at 52.885 GHz with a 3-dB bandwidth of 1 GHz. The maximum output power obtained was 16 mW. Higher gain of about 17 dB was obtained at a reduced bandwidth. The noise figure of the amplifier was 36 dB. Equivalent circuits for the oscillator and the amplifier are derived. The calculated results agree reasonably well with the experimental observations.

25 citations


Patent
29 Jul 1968
TL;DR: In this article, the authors used a phase-locked loop with a phase comparator and a VOLTAGE CONTROLLED OSCILLATOR in order to cope with interference.
Abstract: AN INTEGRATED FREQUENCY SELECTIVE CIRCUIT PARTICULARLY USED FOR DEMODULATING AN FM SIGNAL WHICH INCLUDES A PHASE LOCKED LOOP HAVING A PHASE COMPARATOR COUPLED TO A LOW PASS FILTER AND AMPLIFIER WITH IN TURN HAS AN OUTPUT VOLTAGE WHICH IS THE DESIRED DEMODULATED INPUT SIGNAL AND IS COUPLED TO A VOLTAGE CONTROLLED OSCILLATOR. THE FREQUENCY OUTPUT OF THE OSCILLATOR PROVIDES THE OTHER INPUT TO THE PHASE COMPARATOR TO COMPLETE THE LOOP. WITH THE USE OF THE PHASE LOCKED LOOP, TOLERANCE VARIATIONS GREATER THAN 10% IN INTEGRAL CIRCUIT ELEMENTS CAN EASILY BE TOLERATED. BACK TO BACK DIODES MAY BE INCORPORATED IN THE CIRCUITS TO PROVIDE LIMITING ACTION FOR IMPROVED INTERFERENCE REJECTION.


Patent
03 Oct 1968
TL;DR: In this article, a gate is controlled by the output of a comparator circuit which compares the amplitude of a ramp signal with the DC control voltage, and the gate passes the oscillator output pulses as long as the ramp signal amplitude is less than the control voltage.
Abstract: A circuit for providing output pulses at a frequency determined by a variable DC control voltage. The circuit includes a gate to which an oscillator output is applied. The gate is controlled by the output of a comparator circuit which compares the amplitude of a ramp signal with the DC control voltage. The ramp signal is generated at a frequency which is a subharmonic of the oscillator frequency. The gate passes the oscillator output pulses as long as the ramp signal amplitude is less than the DC control voltage.


Patent
18 Jul 1968
TL;DR: In this paper, a NORMALLY CLAMPED OSCILLATOR OPERates as a high-freewe rt switching CIRCUIT and it is CONTROLLED by an ACTUATABLE OSCillator control controller.
Abstract: THIS IS PROVIDED A HIGH POWER, CURRENT LIMITED, VOLTAGE REGULATED POWER CONVERTER SUITABLE FOR PRINTED CIRCUIT BOARD MOUNTING. A NORMALLY CLAMPED OSCILLATOR OPERATES AS A HIGH FREQUENCY SWITCHING CIRCUIT AND IT IS CONTROLLED BY AN ACTUATABLE OSCILLATOR CONTROL CIRCUIT. THE OPERATING FREQUENCY OF THE OSCILLATOR IS CONTROLLED SO AS TO PROVIDE A DC OUTPUT LEVEL WHICH IS MAINTAINED AT A PREDETERMINED LEVEL. UNDER A CLAMPED CONDITION, USUALLY AT NO LOAD, THE FREQUENCY REQUIRED TO GIVE THIS LEVEL IS THE LOWER OPERATING FREQUENCY LIMIT. A COMPARISON CIRCUIT CONTINUOUSLY COMPARES THE DC OUTPUT VOLTAGE WITH A PREDETERMINED LEVEL SET BY REFERENCE SETTING CIRCUIT. SHOULD THE DC OUTPUT VOLTAGE START TO FALL BELOW THE PREDETERMINED LEVEL, A VOLTAGE SIGNAL IS PRODUCED BY THE COMPARISON CIRCUIT. THIS VOLTAGE SIGNAL IS DIRECTED TO THE OSCILLATOR CONTROL CIRCUIT TO UNCLAMP THE OSCILLATOR TO OSCILLATE AT A FREQUENCY NECESSARY TO RESTOR THE OUPUT VOLTAGE TO THE PREDETERMINED VOLTAGE LEVEL.

Patent
17 Oct 1968
TL;DR: In this paper, a rate control means is used to generate a voltage output proportional to the input control signal and follows and adjust the input signal from one level to another at a predetermined rate, which results in a proportional change in the magnitude and frequency of the inverter output.
Abstract: A variable DC power source supplies a DC voltage to a static inverter which provides a three-phase alternating voltage output to drive an AC motor. A ring counter which is cycled by a voltage controlled oscillator generates three-phase timing signals to control the frequency of the inverter output. An input control signal is coupled to the voltage controlled oscillator through a rate control means. The rate control means generates a voltage output to the voltage controlled oscillator which is proportional to the input control signal and follows and adjustment of the input control signal from one level to another at a predetermined rate. The output generated by the rate control means also controls the magnitude of the DC voltage output of the DC power source. An adjustment of the input control signal results in a proportional change in the magnitude and the frequency of the inverter output.

Patent
03 Apr 1968
TL;DR: In this paper, a frequency synthesizer particularly suitable for VHF applications comprising a pair of variable frequency oscillators adapted to be simultaneously tuned in coarse frequency steps, one of the oscillators being phase locked to a frequency standard, and the second oscillator being controlled by a tunable frequency lock loop referenced to the first oscillator to provide the synthesized frequency output.
Abstract: A frequency synthesizer particularly suitable for VHF applications comprising a pair of variable frequency oscillators adapted to be simultaneously tuned in coarse frequency steps, one of the oscillators being phase locked to a frequency standard, and the second oscillator being controlled by a tunable frequency lock loop referenced to the first oscillator to provide the synthesized frequency output. The tunable frequency lock loop includes a balanced mixer coupled at the outputs of the two oscillators for producing a difference frequency, a frequency discriminator for providing a voltage signal proportional to this difference frequency, a continuously or discretely variable tuning voltage, and a difference amplifier which compares the discriminator output with a selected tuning voltage and provides a difference signal for fine tuning the second oscillator.



Patent
23 Dec 1968
TL;DR: In this paper, the authors proposed a method for compensating the temperature variation in the oscillation frequency of an oscillator wherein an impedance element, for example, a capacitor coupled to the oscillator is switched between two levels of its value, whereby the temperature variations are compensated for on an average.
Abstract: Method of and device for compensating the temperature variation in the oscillation frequency of an oscillator wherein an impedance element, for example, a capacitor coupled to the oscillator is switched between two levels of its value, whereby the temperature variation is compensated for on an average.

Patent
10 Sep 1968
TL;DR: In this paper, a frequency deviation monitor utilizes a reversible or up-down counter for determining the amount of frequency shift of a carrier oscillator signal, which is used to count down a reversible counter having the unshifted frequency stored therein.
Abstract: A frequency deviation monitor utilizes a reversible or up-down counter for determining the amount of frequency shift of a carrier oscillator signal. A modulating signal is peak detected and thence applied to the carrier oscillator to shift the output frequency. This shifted frequency is used to count down a reversible counter having the unshifted frequency stored therein. The difference between the counts during a predetermined time interval is determinative of the frequency deviation.

Patent
15 Aug 1968
TL;DR: In this paper, a frequency modulation signal demodulation system is described, which utilizes the amplitude modulation information inherent in a noise-corrupted frequency modulation carrier to control the parameters of a feedback loop, through which the demodulated FM information is passed, during the occurrence of large noise-induced, pulselike disturbances in the demoded frequency modulation information.
Abstract: Described herein is a frequency modulation signal demodulation system which utilizes the amplitude modulation information inherent in a noise-corrupted frequency modulation carrier to control the parameters of a feedback loop, through which the demodulated FM information is passed, during the occurrence of large noise-induced, pulselike disturbances in the demodulated frequency modulation information. This function is performed by a circuit configuration which includes an amplitude modulation demodulator and a frequency modulation demodulator supplied in parallel from the input to the system for deriving information signals which are respective functions of the instantaneous envelope information and the instantaneous frequency modulation information. The control of the parameters of the feedback loop may be accomplished by the instantaneous envelope information directly or by the envelope information on which some process has been performed. The description also refers to the fact that the envelope detector may have linear or nonlinear characteristics. One way in which the envelope information may be processed is by a nonlinear quantizer followed by a time delay circuit which is interposed between the envelope demodulator and the means for controlling the feedback loop which modifies the frequency modulation information signals. The final output signals may be taken from the output of the feedback loop through a low-pass filter. If desired, an equalizing filter may also be interposed between the output of the feedback loop and the final low-pass filter.

Patent
06 Jun 1968
TL;DR: In this article, a phase-locked oscillator is used to locate the selected data records accurately during readout of a magnetic storage system, where the frequency and phase of the oscillator are controlled by a voltage controller.
Abstract: A phase-locked oscillator useful for a magnetic storage system receives timing pulses from a means for generating reference pulses connected to a rotary storage medium. Variations in the angular velocity and phase of the rotating storage medium result in corresponding variations of frequency and phase of a voltagecontrolled oscillator, which controls the write or record circuitry. During readout, the phase-locked oscillator is employed to locate the selected data records accurately.

Patent
C Hill1
27 Dec 1968
TL;DR: A phase-locked voltage controlled oscillator with an automatic sweep and lock-up circuit employing a unijunction transistor relaxation oscillator as the controlling device in the circuit is described in this article.
Abstract: A phase locked voltage controlled oscillator having an automatic sweep and lock-up circuit employing a unijunction transistor relaxation oscillator as the controlling device in the circuit.


Patent
10 Oct 1968
TL;DR: A VOLTAGE CONTROLLED OSCILLATOR as mentioned in this paper is a VOLUME 7, 2017 VOLUME 6, 2019 VOLUME 5, 2019 OSCLLATOR that provides a controllable output over a wide range from a FEW HUNDREDTHS of a HERTZ to a MEGAHERTZ with a high degree of stability.
Abstract: A VOLTAGE CONTROLLED OSCILLATOR PROVIDING OUTPUT PULSES CONTROLLABLE IN FREQUENCY OVER A WIDE RANGE FROM A FEW HUNDREDTHS OF A HERTZ TO MEGAHERTZ WITH A HIGH DEGREE A ACCURACY AND STABILITY. THE OSCILLATOR EMPLOYS A TRANSISTOR CONSTANT CURRENT SOURCE FOR CHARGING AN ADJUSTABLE R-C TIMING CIRCUIT WHICH TRIGGERS A FEEDBACK CONTROLLED SWITCHING TRANSISTOR CIRCUIT. THE SWITCHING TRANSISTOR CIRCUIT ACTIVATES A SEPARATE TRANSISTOR DISCHARGE CIRCUIT WHICH ALSO SERVES FOR ISOLATING THE TRIGGERING INPUT FROM THE SWITCHING TRANSISTOR DURING SWITCHING TO ALLOW RAPID RESET OF THE TIMING CIRCUIT AND TO IMPROVE THE OUTPUT WAVEFORM.



Patent
David H Westwood1
26 Nov 1968
TL;DR: In this paper, a digital stabilized frequency synthesizer has two phase locked loops around the same controlled oscillator, where phase of the oscillator is corrected at a rate which is the same or a submultiple of the channel spacing frequency and means in this loop to select the channel at which the synthesizer operates.
Abstract: 1,237,985. Frequency synthesizers. RCA CORPORATION. 10 Nov., 1969 [26 Nov., 1968], No. 54926/69. Heading H3A. A digital stabilized frequency synthesizer has two phase locked loops around the same controlled oscillator there being means in the first loop whereby phase of the oscillator is corrected at a rate which is the same or a submultiple of the channel spacing frequency and means in this loop to select the channel at which the synthesizer operates, and means in the second loop whereby the oscillator phase is corrected at a variable rate considerably higher than the channel spacing and always a submultiple of the synthesizer output frequency. Voltage controlled oscillator 1 is coupled by variable-ratio divider 22 to phase-discriminator 26 the second input of which is derived from reference oscillator 30 over fixed divider 32: the output of phase discriminator 26 controls the frequency of oscillator 1, via low-pass filter 36. For control of the short-term stability of oscillator 1, it is coupled in a second loop comprising variable ratio divider 40, ganged with divider 22 but only dividing by the first four significant figures set up in divider 22, phase discriminator 44 and high-pass filter 60. The second input of phase discriminator 52 is derived from crystal oscillator 46, whose frequency is controllable over a small range, and fixed divider 50. The output from phase discriminator 44 also controls the frequency of oscillator 46, via low-pass filter 56.

Patent
23 Oct 1968
TL;DR: In this article, the output of an adjustable oscillator is evaluated in a digital frequency counter whose count, together with a signal from a manually settable digital frequency selector, is applied to a comparison circuit.
Abstract: Decadic frequency generator wherein the output of an adjustable oscillator is evaluated in a digital frequency counter whose count, together with a signal from a manually settable digital frequency selector, is applied to a comparison circuit; in response to any disparity between the count and the selector signal, an analogue voltage is applied to a control circuit of the oscillator to effect a corrective adjustment.