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Showing papers on "Parametric oscillator published in 1982"


Journal ArticleDOI
TL;DR: In this paper, it was shown that the maximum reduction of fluctuations that can be obtained in a degenerate parametric amplifier at steady state is by a factor of two, whatever is the ratio between the damping states γ 2 and γ 1 of the two modes which interact in the cavity.

104 citations


Journal ArticleDOI
TL;DR: In this paper, an exact solution for the problem of a harmonic oscillator of frequency 0 and mass varying with time according to M = MO cos2?t is presented, which is closely related to that of an oscillator with constant mass MO and frequency (?O2 +?2)1/2.
Abstract: An exact solution is presented for the problem of a harmonic oscillator of frequency ?0 and mass varying with time according to M = MO cos2 ?t. The solution is closely related to that of an oscillator of constant mass MO and frequency (?O2 + ?2)1/2. Pseudostationary and quasicoherent states are discussed. Applications in quantum optics are foreseen.

49 citations


Journal ArticleDOI
TL;DR: In this article, the authors combined the techniques of statistical and harmonic linearization to develop a linearized approximation theory for the calculation of the second-order statistics (i.e., autocorrelation functions and spectral densities) of nonlinear systems driven by both random and periodic forces.
Abstract: We have combined the techniques of statistical and harmonic linearization to develop a linearized approximation theory for the calculation of the second-order statistics (i.e., autocorrelation functions and spectral densities) of nonlinear systems driven by both random and periodic forces. For the special case of a Duffing oscillator (a damped anharmonic oscillator with a cubic nonlinearity) driven by Gaussian white noise and by a sinusoidal force, explicit expressions for the renormalized (linearized) frequency, the autocorrelation function, and the spectral density of the oscillator displacement in terms of all the system parameters have been derived. We have determined the region of the parameter space in which the applied periodic force has a significant influence on the second-order statistics of the oscillator.

39 citations


Journal ArticleDOI
TL;DR: In this paper, a method for analyzing multidegree-of-freedom systems having a repeated natural frequency subjected to a parametric excitation is presented, where the analysis is based on the method of multiple scales.

26 citations


Patent
11 Feb 1982
TL;DR: In this article, a linear sweep frequency modulator for a varactor tuned transistor microwave oscillator used in an FM/CW radio altimeter where the oscillator-frequency v. varactor bias characteristic is non-linear.
Abstract: A linear sweep frequency modulator for a varactor tuned transistor microwave oscillator used in an FM/CW radio altimeter where the oscillator-frequency v. varactor bias characteristic is non-linear. A linear triangular wave is converted by means of a function generator to the non-linear wave required for varactor bias to cause linear frequency modulation of the oscillator. Linearity of modulation is tested by measuring variations in the period of a calibration signal derived from a delay line. Variations in the period of the calibration signal are measured by determining the difference between the average and the instantaneous calibration period and sampling the difference during each cycle of the triangular wave, once during the upswing thereof when the oscillator is at low frequency and once during the down swing thereof when the oscillator is at high frequency and separately integrating the up swing and down swing samples. By applying both results of integration to the function generator it thereby has its biases controlling the low frequency and the high frequency operation of the oscillator separately adjusted.

21 citations


Journal ArticleDOI
TL;DR: In this article, the high-frequency amplification properties of transformer coupled, resistively shunted Josephson tunnel junctions have been investigated and the importance of the shunt loop inductance is stressed.
Abstract: The high‐frequency amplification properties of transformer coupled, resistively shunted Josephson tunnel junctions have been investigated. The importance of the shunt loop inductance is stressed. It allows a high cutoff frequency, of significance for good high‐frequency performance. The self‐pumped parametric amplifier showed none of the excessive noise rise, which has hitherto plagued the development of externally pumped Josephson junction amplifiers. Around 10 GHz, we estimated a noise temperature less than 30 K for an amplifier pumped by a Josephson oscillation with a frequency well above twice the signal frequency. The corresponding gain of 5 dB may be increased in a better impedance matched circuit. The gain was very stable against variations in the bias conditions. A gain‐bandwidth product as high as 0.3 was registered. The experimental results agreed well with the established theory for self‐pumped parametric Josephson amplifiers. It should be possible to extend the low noise amplification by this ...

20 citations



Patent
19 Aug 1982
TL;DR: In this article, 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 varactors circuit comprising a modulation varactor and a control varactor to produce a modulated output.
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.

19 citations


Journal ArticleDOI
TL;DR: In this paper, a method to solve the general equation of a damped harmonic oscillator subjected simultaneously to the resistance of a medium and to sliding friction is presented, which subdivides the motion into single halfcycles.
Abstract: We present here a method to solve the general equation of a damped harmonic oscillator subjected simultaneously to the resistance of a medium and to sliding friction; it subdivides the motion into single half‐cycles. The solutions found, which in particular cases reproduce the well‐known ones, have been compared with the results of a typical experiment and satisfactory agreement is found.

19 citations


Patent
15 Jun 1982
TL;DR: In this article, an IMPATT diode oscillator is coupled to a first transmission line in turn coupled to the bias port at one end and to a coupled line transformer formed with a second transmission line at the other.
Abstract: An IMPATT diode oscillator wherein the diode is coupled to a first transmission line in turn coupled to a bias port at one end and to a coupled line transformer formed with a second transmission line at the other A stabilizing load is coupled to the first transmission line between the diode and the bias port A first tunable resonator controlling the fundamental frequency of the oscillator and a second tunable resonator controlling the second harmonic frequency of the oscillator are coupled to the first transmission line between the diode and the stabilizing load so that independent control of the fundamental and the second harmonic is attained in a temperature stable device

16 citations


Journal ArticleDOI
TL;DR: In this article, a numerical analysis of the three-wave parametric interaction with the aim of finding anomalously wide frequency bands of eollinear amplification was made, and it was reported that frequency doubling of this radiation in a KDP crystal can be used to generate wide-band (spectral width ~1000 cm−1) radiation in the region of 0.5 μ.
Abstract: A numerical analysis is made of the three-wave parametric interaction with the aim of finding anomalously wide frequency bands of eollinear amplification. A report is given of experimental attainment of collinear generation of 1-μ radiation with a spectral width ~3000 cm−1 in a superluminescent parametric oscillator utilizing a KDP crystal (oo–e interaction) pumped by the second harmonic of a phosphate glass picosecond laser. It is also reported that frequency doubling of this radiation in a KDP crystal can be used to generate wide-band (spectral width ~1000 cm−1) radiation in the region of 0.5 μ.

Journal ArticleDOI
TL;DR: In this paper, the sum frequency mixing of fourth or third harmonic pulses of a mode-locked YAG laser with tunable pulses produced by a LiNbO 3 parametric oscillator was used.

Patent
18 Jan 1982
TL;DR: In this paper, the authors present a circuit for measuring the reactance of an AC reactance sensor (12, 14, 16) which varies responsive to a condition to be sensed, such as pressure.
Abstract: Circuit for measuring the reactance of an AC reactance sensor (12, 14, 16) which varies responsive to a condition to be sensed, such as pressure. The circuit comprises an oscillator (34) coupled to the sensor (12) for providing a time varying oscillator signal having a variable frequency and a substantially constant peak to peak voltage to the sensor, and a plurality of rectifiers (22, 24, 26, 28, 30 and 32) coupled to the oscillator and to the sensor for providing the oscillator signal as a charging signal to the sensor and for providing discharging signals from the sensor, the discharging signals being a function of the reactance of the sensor, and an amplifier (70) coupled to the rectifiers and to the oscillator for providing an input control signal to the oscillator to control the frequency of the oscillator signal as a function of the reactance of the sensor.

Patent
20 Sep 1982
TL;DR: In this paper, a biconical antenna is connected together at the apex by a pair anti-parallel diodes through a pair of parallel conductive whiskers or wires.
Abstract: A biconical antenna, the halves of which are connected together at the apex by a pair anti-parallel diodes through a pair of parallel conductive whiskers or wires. A pair of quasi-optical lenses focuses energy from a local oscillator and from a submillimeter radio source, respectively, onto the diode pair in the end-fire and broadside direction, respectively. The diode pair spacing is equal to the half wavelength of the local oscillator energy. The local oscillator energy is common mode rejected and causes the incoming radio energy to be sampled by forward biasing the anti-parallel diode pair in synchronism with each zero crossing of the local oscillator energy. Accordingly, the local oscillator energy and noise virtually do not affect the current flow between the halves of the biconical antenna. The current flow represents an intermediate frequency signal corresponding to the difference in frequency between the incoming radio signal frequency and the local oscillator frequency. Thus, local oscillator energy is mixed with incoming radio energy without permitting local oscillator noise to degrade the resulting mixed signal.

Journal ArticleDOI
TL;DR: In this article, an analysis of reflection parametric amplifiers using superconductor-insulator-superconductor (SIS) junctions is presented, where both singly degenerate (three-photon) and doubly-deletive (four-phonon photon) schemes are possible.
Abstract: An analysis of reflection parametric amplifiers using superconductor‐insulator‐superconductor (SIS) junctions is presented. Both singly degenerate (three‐photon) and doubly degenerate (four‐ photon) schemes are possible. Due to the fact that the reactive part of the quasiparticle response function Re j1 rises steeply just below the gap frequency, whereas the resistive part Im j1 remains 0 until the gap, the SIS junction may be operated as a purely reactive device. The quantum limit for detectable power h/ω B is therefore achievable.

Journal ArticleDOI
TL;DR: In this paper, experimental results on a 35 GHz 250 kW gyrotron oscillator (TH 1501 A) are first summarized, and the project of a 70 GHz oscillator operating on the second harmonic of the cyclotron resonance is then discussed, and first experimental results are described.
Abstract: In this paper, experimental results on a 35 GHz 250 kw gyrotron oscillator (TH 1501 A) are first summarized. The project of a 70 GHz oscillator operating on the second harmonic of the cyclotron resonance is then discussed, and first experimental results are described. Theoretical work on space charge effects in a single orbit cylindrical beam oscillator is also reported. Numerical results indicate typically a 15% decrease in logarithmic gain.

Journal ArticleDOI
R.N. Bates1
TL;DR: In this article, a 2nd-harmonic transferred-electron oscillator and a scale model were used for determining the resonant frequency of the oscillator once the diode parasitic reactances are defined.
Abstract: Measurements performed on a 2nd-harmonic transferred-electron oscillator and a scale model are reported. A method is described for determining the resonant frequency of the oscillator once the diode parasitic reactances are defined.

Journal ArticleDOI
TL;DR: In this article, the behaviour of the dynamical system x = y, y = −x−μ sin y is studied in the context of electrical circuit theory, where the authors focus on the behavior of the system x and y.
Abstract: This note is concerned with the behaviour of the dynamical system x = y, y = −x−μ sin y which is important in electrical circuit theory.

Journal ArticleDOI
01 Aug 1982
TL;DR: In this paper, the statistics of an ensemble of oscillators excited by an external field in a heat bath is considered with the help of the double averaging method and the quasi-probability distribution function method.
Abstract: The statistics of an ensemble of oscillators excited by an external field in a heat bath is considered with the help of the double averaging method and the quasi-probability distribution function method. The parametric resonance and the force-induced resonance cases are considered. The present models show that there are conditions when non-linearity of oscillators, or fast phase relaxation, or non-monochromaticity of the external field promotes the excitation of oscillators. Experiments in which the increase of excitation of polyatomic molecules in an IR laser field was caused by a buffer gas have been discussed in the literature. This effect might accrue due to the increase of the phase relaxation rate. A possible control experiment to verify this statement is given.

Journal ArticleDOI
TL;DR: In this paper, the Wigner phase space method is applied to the problem of a harmonic oscillator with a time dependent force constant, which may be thought of as a model for collisions involving harmonic oscillators.
Abstract: The Wigner phase space method, suggested by Heller, is applied to the problem of a harmonic oscillator with a time dependent force constant, which may be thought of as a model for collisions involving harmonic oscillators. The method leads to an exact solution of the problem.

Journal ArticleDOI
TL;DR: In this article, the 11th harmonic mixing signals between a 386 GHz oscillator and a 4.25 THz laser with a signal to noise ratio of 25 dB in 100 kHz bandwidth have been obtained with a Schottky diode.
Abstract: The 11th harmonic mixing signals between a 386 GHz oscillator and a 4.25 THz laser with a signal to noise ratio of 25 dB in 100 kHz bandwidth have been obtained with a Schottky diode.

Journal ArticleDOI
G.B. Morgan1
TL;DR: In this paper, the effect of temperature on the performance of a dielectric resonator compensated W-band impatt diode microstrip oscillator was shown to be quite small.
Abstract: The effect of temperature on the performance of a dielectric resonator compensated W-band impatt diode microstrip oscillator is shown to be quite small. The frequency change was about 2 MHz/°C as compared to the uncompensated oscillator's 10 MHz/°C. The design of the oscillator is presented and the resonator used was a cuboid of temperature compensated barium nonatitanate.

Patent
21 Oct 1982
TL;DR: In this paper, an active low-pass filter is connected downstream of the oscillator, which, in the same way as the frequency, is varied in terms of its limit frequency by the control current, and this control current flows through the LEDs contained in optocouplers.
Abstract: To generate a harmonic-free sine-wave oscillation whose frequency can be modified continuously within specific limits depending on a control current supplied from an external voltage source, an active low-pass filter is connected downstream of the oscillator which, in the same way as the frequency of the oscillator, is varied in terms of its limit frequency by the control current, and this control current flows through the LEDs contained in optocouplers which in turn illuminate photoresistors whose resistance value which is dependent on the radiation intensity is frequency-defining in the oscillator and limit-frequency-defining in the low-pass filter. If, for example, the frequency of the oscillator increases due to an increasing control current, the same control current will likewise increase the limit frequency in the active low-pass filter to such an extent that the fundamental wave can pass unchanged, whereas all the harmonics are blocked.

Journal ArticleDOI
TL;DR: In this paper, a precision thermometer using the NQR absorption of KC10 3 has been developed, where the super-regenerative oscillators with frequency locking has been used as the sensor oscillator in order to avoid the defects of the conventional SRSO.

Journal ArticleDOI
D.J. Harris1, S. Mak1
TL;DR: In this article, an oversized-cavity millimetre-wave IMPATT oscillator has been constructed, which can be easily coupled to a groove guide via a simple transformer, and a resonant-cap structure is used to determine the frequency of oscillation.
Abstract: An oversized-cavity millimetre-wave IMPATT oscillator has been constructed which can be easily coupled to a groove guide via a simple transformer. A resonant-cap structure is used to determine the frequency of oscillation. The oversized-cavity results in the Q of the oscillator being greater than that of a conventional impatt oscillator, but the output power and frequency are nevertheless stable. The tuning characteristic is discussed and a frequency spectrum presented.

Journal Article
TL;DR: In this paper, the effect of the initial state and parametric pumping on the sensitivity of a gravitational detector is discussed in the quantum limit and the possibility of a considerable increase in sensitivity in the parametric resonance regime is demonstrated.
Abstract: The effect of the initial state and of parametric pumping on the sensitivity of a gravitational detector is discussed in the quantum limit The possibility of a considerable increase in sensitivity in the parametric resonance regime is demonstrated

Journal ArticleDOI
TL;DR: In this paper, a theoretical study of the influence of a longitudinal optical inhomogeneity of a nonlinear crystal on the value and spectral dependence of the gain, which is calculated numerically for arbitrary parameters of the inhomogeneous.
Abstract: A theoretical study is made of the influence of a longitudinal optical inhomogeneity of a nonlinear crystal on the value and spectral dependence of the gain, which is calculated numerically for arbitrary parameters of the inhomogeneity. An analytic dependence of the gain in the inhomogeneity parameters is obtained in the two most typical cases of a weak inhomogeneity (linear and step) in nonlinear LiNbO3 crystals. A study is made of the influence of an inhomogeneity on the width and shape of the parametric gain profile. The results are used to formulate requirements in respect of the inhomogeneity parameters of nonlinear crystals suitable for optical parametric oscillators. A report is given of an experimental study of the dependence of the average power of a singly resonant parametric oscillator on the inhomogeneity parameter of an LiNbO3 crystal. The experimental results confirm the theoretical predictions.


Journal ArticleDOI
TL;DR: Using exact wave functions of the cranked triaxial harmonic oscillator model in coordinate space, an expression for the single-particle probability current density was derived in this paper.
Abstract: Using exact wave functions of the cranked triaxial harmonic oscillator model in coordinate space, an expression for the single-particle probability current density is derived. This expression, valid to all orders in the angular velocity is then used to calculate current distributions for some typical harmonic oscillator single-particle states. Comparisons with perturbative first-order calculations indicate differences at high angular velocities where new features of the current distributions become apparent. This suggests the extension of the present calculations to real nuclei.