Showing papers on "RLC circuit published in 1969"

Large-signal analysis of a silicon Read diode oscillator

Abstract: This paper presents theoretical calculations of the large-signal admittance and efficiency achievable in a silicon p-n-v-ns Read IMPATT diode. A simplified theory is employed to obtain a starting design. This design is then modified to achieve higher efficiency operation as specific device limitations are reached in large-signal (computer) operation. Self-consistent numerical solutions are obtained for equations describing carrier transport, carrier generation, and space-charge balance. The solutions describe the evolution in time of the diode and its associated resonant circuit. Detailed solutions are presented of the hole and electron concentrations, electric field, and terminal current and voltage at various points in time during a cycle of oscillation. Large-signal values of the diode's negative conductance, susceptance, average voltage, and power-generating efficiency are presented as a function of oscillation amplitude for a fixed average current density. For the structure studied, the largest microwave power-generating efficiency (18 percent at 9.6 GHz) has been obtained at a current density of 200 A/cm2, but efficiencies near 10 percent were obtained over a range of current density from 100 to 1000 A/cm2.

State-Variable Analysis of RLC Networks Containing Nonlinear Coupling Elements

Abstract: This paper deals with the state-variable analysis of the most general class of lumped time-invariant RLC networks. The hybrid descriptions of coupled elements are discussed in connection with the mixed analysis of networks. Sufficient conditions for the uniqueness of solutions of coupled resistor networks and RLC networks are given in terms of hybrid descriptions. The set of state variables are taken so that the order of state equations coincides with the number of finite natural frequencies in the linear case. A simple method for determining such a set of state variables by means of two particular trees, C -normal tree and L - normal tree, is also presented. The standard form of state equations are represented by means of a signal flow graph.

A Multiple-Diode High-Average-Power Avalanche-Diode Oscillator (Correspondence)

Abstract: This correspondence presents a simple circuit which allows direct combining of the power obtainable from several avalanche diodes. The circuit does not require extremely close matching of dc or RF diode characteristics, and no particular isolating networks such as hybrid combiners are necessary. CW power output exceeding 4 watts at 7 GHz and 3 watts at 9 GHz has been demonstrated in a device employing five diodes. The number of diodes which can be combined using this technique is limited by geometric and heat sink considerations. Descriptions of typical single-diode and multiple-diode oscillators are given along with equivalent circuits. The circuits employ resistors or resistor networks to suppress low-frequency oscillations and undesired resonances which occur when several oscillators are coupled together. Negligible insertion loss is incurred at the design output frequency. Measured performance is given on similar single- and multiple-diode oscillators. Data include frequency, power, AM noise, FM noise, temperature, and loaded Q.

Wide-band strip line frequency-selective circuit

Abstract: A wide-band frequency-selective microwave circuit having ground planes, dielectric layers, and conductive strip sections. The conductive strip sections are in the same plane and juxtaposed to each other to form resonant circuit elements.

Isolator comprising tuned lumped element circulator

Abstract: The present invention relates to an isolator having a low forward direction loss over a very wide frequency range and a sufficiently high backward loss in a desired frequency range, and having a very compact configuration and a simple construction. The isolator according to the present invention comprises a lumped element type circulator which is operative in the desired frequency range, a resonant circuit having its impedance characteristics to be at low impedance in said frequency range and to be at high impedance outside of said frequency range and being connected between outer conductor of the lumped element type circulator and a ground conductor, and an absorbing resistor connected between one of the terminals of the circulator and the outer conductor or the ground conductor.

Automatic fine tuning circuitry

Abstract: A television system includes means for disabling the application of an automatic fine tuning correction voltage to the television tuner while the tuner''s tunable resonant circuits are being adjusted to tune from a first to a second frequency during channel change. During this period, the disabling means establishes a voltage across a variable capacitance device in the tuner''s oscillator tunable resonant circuit to approximate the crossover frequency voltages normally applied to the device from the automatic fine tuning circuits. The automatic fine tuning circuit operation is not affected during channel change, and the correction voltage output signals may be employed in a signal seeking system to help detect the presence of a desired television signal. Whenever the disabling means becomes operative, it actuates other circuitry to cause a muting of the television video and sound signals to occur, as well as the energization of a channel change indicator.

Voltage controlled oscillator in which capacitive diodes become resistive during portions of each cycle

Abstract: By varying the voltage applied to two oppositely poled varactors, placed in series in the resonant circuit of a microwave oscillator, the portion of each oscillatory cycle in which each varactor acts as a capacitor as opposed to a low resistance, is varied, thereby linearly varying the oscillatory frequency of the circuit.

Moisture meter utilizing amplitude and bandwidth signals

Abstract: There is disclosed a meter for measuring on a continuous basis the moisture content of a moving layer of bulk materials such as coal or wood chips. A capacitor has two plates on one side to span a portion of the conveyed bulk material with its field. This capacitor is connected in a resonant circuit which is frequency modulated with a sawtooth modulation wave varying about a particular center frequency which is predetermined for the dielectric constant provided to the capacitor by a known bulk material. Then the amplitude and bandwidth of the resonant circuit frequency response is a function of the moisture content and quantity of bulk material in the capacitor field. An analog computer then takes a ratio to produce a direct reading as a percentage of moisture content.

Broadband Negative Resistance Oscillator Circuits

Abstract: Negative resistance oscillators can perform various functions other than just fixed frequency oscillations. For example, the electronic tuning effect is commonly used to generate FM signals and the injection locking phenomenon can be utilized for FM amplification, limiting and demodulation. For fixed frequency oscillations, the oscillator resonant circuit is generally designed to have as high an external Q as possible for good frequency stability and noise performance. However, for the other applications mentioned above, relatively broadband circuits are desired. This paper discusses various factors to be considered in their design.

Circuit arrangement for generating a line frequency parabolically modulated sawtooth current of field frequency through a field deflection coil

Abstract: A TV deflection system that includes a circuit for generating a sawtooth field current parabolically modulated at the line frequency in the field deflection coil. The circuit includes a resonant circuit composed of a capacitor and the field deflection coil with a resonant frequency that is approximately one fifth of the line frequency for deriving the parabolic modulation component of line frequency. The sawtooth field deflection generator periodically excites the resonant circuit via a bidirectional electronic switch that is periodically switched in synchronism with the line flyback pulses.

Generation of stepped voltages for color television and the like

Abstract: This specification discloses a high voltage switching system for driving the screen of a color television picture tube in order to generate different color images on the screen thereof in accordance with different video signals. The switching system comprises a transformer, which is connected into a resonant circuit with the capacitance provided by the screen of the color television system. The inductance provided by the transformer is periodically switched between low and high inductance and simultaneously with the switching, energy is coupled into and out of the resonant circuit to generate a step waveform across the capacitance provided by the screen of the picture tube.

Standard field strength meter

Abstract: A hollow conductive sphere having a narrow insulated gap along an equator is suspended in a radio frequency electromagnetic field with the plane of the gap perpendicular to the electric field vector. The sphere halves are electrically connected together by a series resonant LC circuit disposed in the sphere. The resonant circuit is tuned to the frequency of the field. The field impinging on the sphere causes a current to flow across the equator of the sphere, via the resonant circuit. The field strength can accurately be related to the resonant current by an analysis of the scattering of the field by the sphere. To measure the current, the sphere contains a circuit for detecting the voltage developed across the inductance of the LC circuit and for energizing a miniature incandescent lamp when the detected voltage exceeds a threshold value. The light from the lamp is visible through a small diameter tube disposed through the sphere wall (the tube is a waveguide below cutoff for the impinging field). The sphere thus provides an optical indication when the field exceeds a threshold or standard field value. The sphere is calibrated by adjusting the threshold circuit to cause the lamp to light when the appropriate radio frequency current is passed through the resonant circuit. The calibration current is applied to the sphere by means of two hollow conductors of the same diameter as the sphere which are connected to the two sphere halves near the equator containing the insulated gap. The two hollow conductors form the inner conductor of a coaxial line. The calibration current applied to the coaxial line thus flows across the gap just as the induced current does when the sphere is in the field being tested.

Envelope delay correction link

Abstract: A circuit for correcting nonuniform transmission delay of a television signal has two parallel coupled channels coupled to receive said signal. The first contains a damped resonant circuit, the second a phase inverter. A MOSFET can be the variable damping, while voltage variable diodes can be in the tuned circuit. A rectifier supplies a control voltage from the input signal to the diodes.

Varactor-controlled pn junction semiconductor microwave oscillation device

Abstract: A solid state microwave generating device comprising a 3-terminal element having a p-n junction representing a negative resistance and a junction of which the junction capacitance is varied according to a voltage applied thereto. A reverse voltage is imparted to said p-n junction so that the latter is maintained in a negative resistance condition resulting from an avalanche current. The other junction is set to a suitable reactance value so as to produce a microwave of a tuned wavelength, and under such a condition a modulating signal is supplied in superimposition to said other junction to thereby change the reactance value thereof, thus effecting microwave modulation. With this device, the oscillation wave occurring in a resonator circuit is controlled in accordance with lumped constants so that the tuning operation of the resonant circuit, modulation (FM), automatic frequency control (AFC) and so forth can be easily and efficiently performed.

Characterization and Modeling of the 709 Integrated Circuit Operational Amplifier in an Ionizing Radiation Environment

Abstract: An empirical technique for simplified computer modeling of a 709 operational amplifier integrated circuit in an ionizing radiation environment is presented. The model makes use of an RLC network and a voltage-transfer curve to model the normal electrical operation of the 709. An additional voltage generator models the radiation response. Comparisons between the radiation response predicted by the model and observed radiation response are shown.

Diode mount having integral resonant circuit

Abstract: A SEMOCONDUCTOR MOUNTING PACKAGE INCORPORATING ITS OWN RESONANT CIRCUIT IS DISCLOSED FOR MILLIMETER WAVEGUIDE USE. THE APPARATUS COMPRISES A METAL STUD HAVING TWO SPACED METAL PROJECTIONS FORMED ON ITS END SURFACE, A TWO-TERMINAL SEMICONDUCTOR DEVICE MOUNTED ON THE SURFACE BETWEEN THE PROJECTIONS, AND A METAL RIBBON CONNECTING THE UPPER DEVICE TERMINAL TO A SOURCE OF BIAS ENERGY. THE RIBBON, THE PROJECTIONS, THE STUD SURFACE, AND MEANS PROVIDING A LOW IMPEDANCE PATH FOR MILLIMETER WAVE ENERGY ACROSS THE GAPS BETWEEN THE RIBBON AND THE PROJECTIONS FORM A RESONATING LUMPED INDUCTANCE CAVITY AROUND THE DEVICE. THE IMPEDANCE OF THIS PACKAGED CIRCUIT IS OF RELATIVELY SIMPLE FORM, APPROXIMATELY OF A PARALLEL RESONANT CIRCUIT COMPRISING THE DEVICE AND THE LUMPED CAVITY INDUCTANCE. WITH ITS USE OSCILLATORS HAVE BEEN BUILT HAVING GOOD MODULATION SENSITIVITY AND FUNDAMENTAL FREQUENCIES IN THE RANGE OF 60 GHZ.

Tunable coaxial cavity semiconductor negative resistance oscillator

Abstract: A microwave oscillator circuit is disclosed which employs a series connection of a lumped element capacitor and a semiconductor device capable of exhibiting negative resistance. The capacitance of the capacitor is series resonated with its self inductance to form the principal frequency determinative element of the resonance circuit, whereby broadband tuning is achieved with a relatively simple and thus inexpensive resonator circuit.

Triggerable pulse generators

Abstract: A triggerable pulse generator of the type having a series sequence of triggerable switches, that require priming, fed via a saturable inductance, a pulse forming network and a charging circuit to which D.C. voltage is applied has connected in shunt across each of the triggerable switches a damped series resonant circuit. The damped series resonant circuit is so dimensioned as to provide, for the switch with which it is in shunt the required correct priming current pulse for that switch.

Circuit arrangement for producing a line-frequency sawtooth-current having a field-frequency-varying amplitude in a television display device

Abstract: A TV deflection circuit for producing a line frequency sawtooth current whose amplitude varies at the field frequency said variation being approximately parabolic to provide East - West raster correction for any pincushion distortion and approximately sawtooth shaped to provide color correction in the case of a color TV tube. The circuit includes a modulator having an electronic switch controlled by a line frequency signal. During the forward stroke of the constant amplitude sawtooth current supplied by a line deflection current generator to the line deflection coil, the switch connects a field deflection current generator to a resonant circuit including the parallel combination of a capacitor and an inductor. The inductor comprises either the line or field deflection coils, or both. The resonant circuit has a resonant period that is approximately twice the flyback time of the line frequency deflection current.

Voltage-regulating device

Abstract: A voltage-regulating transformer having coil connected in series with a condenser to form a resonant circuit at the frequency of the source potential, and a ferromagnetic core having one or more magnetic gaps in the flux path of the coil. In different embodiments, the resonant input circuit utilizes separate condensers coupling the source to opposite ends of the coil, and a shunt capacitor across the coil. In separate embodiments, power is taken from the transformer by connection across the coil and by magnetic coupling through a second coil. The voltageregulating device has the advantage of producing an output potential substantially more stable than the source potential, an output potential substantially sinusoidal in waveform and an output which collapses on overload to inherently protect the device against overloads.

Solid state television tuner with voltage variable capacitors

Abstract: A solid state television tuner is disclosed herein. Actuation of a channel selector mechanism to one of a plurality of channel selection settings connects a distinctive level of voltage to a wide band signal selecting circuit. The signal selecting circuit includes a resonant circuit having solid state voltage variable capacitance that is selectively controllable in accordance with the level of applied voltage. A different voltage level is connected for each of the channel selection settings and each is independently controllable through actuation of preset tuning mechanism only when connected for effecting fine tuning of the channel.

Envelope delay compensation circuit

Abstract: A network to compensate for group delay having a pair of circuit paths with a variable delay network in one path and a fixed delay network in the other path. The input information is coupled to both circuit paths and the output of the two paths is combined in a differential amplifier to produce a vector addition of the signals from the separate paths. An isolation network is provided in the variable delay circuit path and a resonant circuit is provided to have an adjustable Q and adjustable frequency of resonance and is also located in the same path. Means are provided to adjust the relative amplitudes of the two signals so that the resulting output of the differential amplifier will have a substantially constant amplitude regardless of the output frequency or phase.

Application of a Variable Resistance to Arrest Oscillations in a Pulsed Capacitor Discharge Circuit

Abstract: Kirchhoff's equation for the current flow from a capacitor connected in series with an inductance and a resistance that varies with current is solved by an iterative integration scheme. The resistance of the circuit is assumed to increase during the discharge due to Joule heating. The conditions for over‐, under‐, and critical damping are derived such that a circuit can be designed that has a short risetime and a long decay time without current oscillation. The realistic nature of the circuit is verified experimentally.

Method and apparatus for regulating voltage by utilizing the stable oscillation state of a parametric device

Abstract: A METHOD OF REGULATING VOLTAGE BY TRANSFERRING ENERGY FROM AN UNREGULATED VOLTAGE SOURCE TO A PARAMETRIC DEVICE TO MAINTAIN IT IN ITS STABLE OSCILLATING STATE. A METHOD OF FILTERING EMPLOYING THE SAME PARAMETRIC PRINCIPLES IS ALSO DISCLOSED, AS ARE PARAMETRIC DEVICES IN WHICH A CAPACITOR IS COUPLED TO AN INDUCTOR TO FORM A RESONANT CIRCUIT, THE INDUCTANCE OF THE INDUCTOR BEING VARIED ELECTRICALLY AT TWICE THE FREQUENCY TO WHICH THE RESONANT CIRCUIT IS TUNED.

Varactor controlled afc circuit for wide band tuner

Abstract: An AFC control circuit for an oscillator that is tunable over a wide frequency band produces a relatively constant frequency change or ''''pull-in'''' range at any frequency value within the band. The control circuit is connected across the main capacitance of the oscillator''s resonant circuit and is comprised of a varactor and a parallel inductance that define a reference resonant frequency lower than any frequency value within the band. The control circuit exhibits an effective capacity at all frequencies of interest and the varactor provides a change in such effective capacity which is related to operating frequency in a manner to achieve the uniform ''''pull-in'''' characteristic.

Circuit for determining deviation from resonance of lc networks by cancelling inphase component and sensing quadrature component

Abstract: A circuit for measuring the deviation of resonance of a series LC circuit includes an operational amplifier with the series LC circuit connected in a feedback path. The amplifier output is connected to both an inphase discriminator and a quadrature discriminator. The output of the inphase discriminator controls an inverted inphase circuit to cancel out a substantial portion of the inphase component of the amplifier output which is applied to the quadrature discriminator. A circuit for measuring the deviation from resonance of a parallel resonance LC circuit includes a transformer with one side of the secondary connected in series with the operational amplifier and the LC circuit and with the opposite side of the transformer connected by a radiant energy controlled resistor to the input of the amplifier. The radiant energy controlled resistor is controlled by a lamp operated by an inphase discriminator to cancel a substantial portion of the inphase component of the signal through the parallel resonant circuit.

Tunable oscillator circuit employing an active rc notch filter circuit

Abstract: A tunable oscillator circuit employing a resistor capacitor (RC) active notch filter in the feedback path. Two variable resistances are included in the oscillator circuit, one for independently setting the notch depth of the filter, and the other for independently adjusting the frequency of oscillation.

Circuit Model Simulation of Gunn Effect Devices

Abstract: A circuit model of the Gunn device that retains both the time dependent and nonlinear device properties is presented. The model is based on the physical properties of a high-field domain in a uniformly doped sample and represents this domain and the remainder of the device by appropriate circuit elements. A computer program has been written that allows the device to be connected to any combination of RLC elements up to and including two parallel RLC circuits in series. Computer calculations have been made with a low resistance series circuit to simulate the Gunn mode of operation. The variation of Gunn frequency with bias voltage has been calculated and is in qualitative agreement with experiments. An inductance of 1 nH in series with 1 ohm is found to significantly alter results in comparison with the pure resistive case. The effect of this series inductance has also been observed experimentally as a lack of harmonics in resistive device mounts with stray inductance. Results obtained with a parallel RLC circuit point out the importance of circuit voltage control on the domain behavior. The LSA diode is treated as a bulk conductance following the drift velocity-electric field curve for GaAs. The bulk velocity and differential mobility are approximated by polynomials of electric field from which the device equivalent circuit is obtained. A physical insight into the operation of the LSA device is gained through a plot of time-integrated differential mobility with time. It is shown that an RF load for which this integral does not change appreciably over an RF period results in maximum efficiency. Results of efficiency and negative resistance of the device obtained for a bias field of 10 kV/cm are presented and are in good agreement with calculations of other workers.