Showing papers on "Voltage-controlled oscillator published in 1987"

Local oscillator induced instabilities in trapped ion frequency standards

Abstract: The trapped ion frequency source is one of a class of passive atomic frequency standards that necessarily use an ancillary frequency source to interrogate the atomic transition. For passive atomic sources such as Rubidium standards, ultimate long term performance of the source is not dependent on this local oscillator, except to the extent limited by feedback gain. For the trapped ion source this immunity to local oscillator phase noise is lost. In contrast to the Rubidium source, a sequential measurement procedure is used in which the signal from the local oscillator is sensed only some of the time. Since the local oscillator is only periodically sampled, certain short term fluctuations in the local oscillator frequency will give rise to long term fluctuations in the difference between the stabilized local oscillator frequency and that of the atomic absorption. We have performed calculations of the influence of such phase noise fluctuations in the reference oscillator on the performance of the standard as a function of duty cycle for a local oscillator with frequency fluctuations showing a 1/f spectral density, as is typically shown by crystal Quartz oscillators for long measuring times (1-100 seconds). Expressions are generated for the limiting trapped ion -1/2 variance due to the local Oscillator for various values for the duty factor d. Explicitly treated are the cases d<1, d=1-6, (6 < 1) and d = 1/2. It is seen that for a duty factor < 90%, local Oscillator performance equal to that of the ion standard (for a measuring timer equal to the period te of the sampling cycle) will significantly degrade the characteristic 1-1/2 passive atomic standard performance. For d near 1, (6 = (1-d) < 1) an approximately linear dependence of this degradation on 6 is found.

Multielectrode distributed feedback laser for pure frequency modulation and chirping suppressed amplitude modulation

Abstract: A new concept for operation of distributed feedback lasers with multielectrodes is proposed and its capability for amplitude or frequency modulation is demonstrated. The device has electrically separated electrodes so that carrier density distribution along the laser cavity can be controlled artificially by adjusting the current distribution for each electrode. The lasing frequency can be controlled by changing the current ratio applied to the electrodes. Frequency modulation experiments disclose that neither frequency modulation efficiency nor phase delay depend on modulation frequency. It turned out that the frequency shift under modulation showed blue shift or red shift depending on bias current distribution and the position of the modulation applied electrode. Using these characteristics, chirping suppressed amplitude modulation and frequency modulation with constant output power are realized.

Phase and frequency detector circuits

Abstract: A Phase/Frequency Locked Loop comprises a controllable oscillator which is phase locked with the clock of an incoming non-return-to-zero digital data signal. The controllable oscillator may be a voltage-controlled oscillator (VCO) or may be purely digital. The circuitry includes a novel digital phase and frequency detector which detects both frequency and phase error by sampling the incoming data stream at multiple phases of the output of the VCO (or the digital equivalent thereof). One of two binary disagreement signals are produced depending on the sense of the phase error. During periods of frequency error, the circuit automatically selects the proper type of disagreement signal (the leading-edge disagreement) required to achieve frequency lock.

Automatic tuning system for ultrasonic generators

Abstract: Apparatus for periodically sweeping a voltage controlled oscillator over a range of frequencies which includes a resonant frequency of a transducer being supplied with power by the voltage controlled oscillator through a power amplifier. The apparatus includes a digital phase detector having a voltage input coupled to the output of the power amplifier and a second voltage input coupled to a current sensor indicative of the phase of the current flowing through the supply circuit of the transducer to provie at the output of the phase detector a voltage signal indicative of phase difference between the voltage and the current in the transducer. The output of the phase detector is coupled to a processor and to the input of a summing circuit. The output of the processor is also coupled to the summing circuit to provide an offset voltage which adjusts the voltage controlled oscillator to the resonant frequency of the transducer.

A 30-MHz low-jitter high-linearity CMOS voltage-controlled oscillator

Abstract: A fully monolithic voltage-controlled oscillator (VCO) with an on-chip timing capacitor and a maximum oscillation frequency of 30 MHz is reported. Using a novel on-chip servo loop, the VCO displays less than 0.17% nonlinearity in its voltage-frequency transfer function from 1 to 15 MHz without trimming. An improved circuit topology that provides a large swing on the timing capacitor allows the VCO to obtain a cycle-to-cycle jitter of less than 100 p.p.m. The circuit operates on a 5-V supply with a die size of 104 mil/spl times/154 mil.

A versatile power converter for high frequency link systems

Abstract: The single-phase high frequency link appears to be an attractive alternative to the dc link commonly employed in power conversion systems. This paper proposes a power converter suitable for one-step conversion of the single-phase high frequency link voltage to the three-phase low frequency voltages typically required for interfacing with system sources and loads. The converter is utilizes zero voltage switching principles to minimize switching losses and uses an easy to implement technique of pulse density modulation for the control of the amplitude, frequency and the waveshape of the synthesized low frequency signals. Adaptation of the proposed topology for power conversion to single-phase ac and dc voltage or currents outputs is shown to be straight forward. The feasibility of the proposed power circuit and the control technique have been experimentally verified.

Microwave apparatus for measuring fluid mixtures

Abstract: An apparatus for measuring the concentration of one material in another, such as the concentration of water in crude or refined mineral oil, comprises a conduit for receiving and discharging a continuous flow stream of the fluid mixture and which is formed as part of a coaxial microwave transmission line. A microwave or radio frequency range signal generator in the form of an unbuffered oscillator is connected to the transmission line for generating a high frequency signal which may be varied by a voltage controlled oscillator tuning circuit. A signal receiver monitors the change in frequency caused by impedance pulling of the oscillator due to the change in fluid dielectric constant and transmits a differential frequency signal to a frequency counter and microprocessor for comparison of the measured signal with known reference signals for determining the percentage of one fluid mixed in the other in the flow stream. The apparatus measurement section is adapted to provide for connecting standard microwave coaxial connectors to a relatively large diameter pipe or conduit comprising the coaxial transmission line portion of the measurement section.

Local oscillators for radio receivers

Abstract: A local oscillator for a radio receiver includes a voltage controlled oscillator (VCO), a decoder and controller for providing a control voltage to the VCO, an error detector circuit for detecting an error in the frequency of the VCO on the basis of a received signal processed with the oscillating signal from the VCO, a temperature probe and a memory. The local oscillator is initially set up during manufacture by detecting any errors in the frequency at selected temperatures, and storing data in the memory indicative of the control voltage required to compensate for the frequency error for each temperature. In operation the decoder and controller applies the appropriate control voltage to the VCO on the basis of the data stored in the memory relative to the temperature detected by the temperature probe. If, for example as a result of ageing of the oscillator, the error detector detects an error in the frequency, the decoder and controller adjusts the control voltage to the VCO so as to compensate for the error, and the updated value is stored in the memory for subsequent use. If the received signal is mixed with the oscillating signal in a mixer, the output of intermediate frequency stages can be used for error detection. Alternatively, demodulated data can be used for this purpose, for example in a direct conversion receiver.

Liquid level sensing apparatus

Abstract: A liquid level sensing system comprising a probe and a reactive element carried by the probe. The reactive element forms a portion of a tuned circuit in a voltage-controlled oscillator. The output of the voltage-controlled oscillator is compared to a fixed frequency reference signal and a frequency/phase detector generates a signal indicative of any difference. The frequency/phase detector output is applied to the voltage-controlled oscillator to maintain the output frequency of the oscillator at the frequency of the reference signal. The output of the frequency/phase detector is also differentiated to develop a pulse when the frequency/phase detector output signal varies rapidly, indicating initial contact between the probe and the surface of a liquid held within a container.

Random number generator using sampled output of variable frequency oscillator

Abstract: A random number generator designed for use with an electronic key uses a triangular output analog oscillator to vary the frequency of a higher frequency voltage controlled oscillator. The output of the voltage controlled oscillator is sampled at a rate much less than the rate of oscillation of the voltage controlled oscillator to produce random digital values.

Variable frequency system having linear combination of charge pump and voltage controlled oscillator

Abstract: A phase locked loop system having a non-linear voltage controlled oscillator (VCO) is provided with a variable gain charge pump The charge pump supplies a pump current to an integrating network which transforms the pump current into a frequency-modulating input voltage The frequency-modulating input voltage is applied to an input of the VCO The frequency-modulating input voltage is also coupled to a gain control input of the variable gain charge pump so that the magnitude of the pump current will be a function of the absolute value of the frequency-modulating voltage A substantially constant loop gain may be obtained in the phase locked loop system by arranging the gain function of the variable gain charge pump in counterposed relation to the slope of a VCO transfer function defining the nonlinear relation between the frequency-modulating input voltage of the VCO and the output frequency of the VCO

Phase locked loop circuit with quickly recoverable stability

Abstract: A PLL circuit for a phase comparator, a low-pass filter (LPF), a voltage-controlled oscillator (VCO) and a frequency divider. A first control circuit is responsive to a discontinuous phase change of a reference signal of the PLL circuit for inhibiting the operation of the phase comparator or disconnecting the LPF from the phase comparator during a predetermined period so that the discontinuous phase change information is not transmitted through the LPF to the VCO. At the same time, a second control circuit resets the frequency divider by a pulse of the reference signal after the discontinuous phase change or applies a voltage corresponding to the discontinuous phase change to the VCO so that the output signal of the frequency divider is locked in phase to the reference signal after the discontinuous phase change. With the cooperation of the first and second control circuits, the PLL circuit quickly recovers its stable state after the discontinuous phase change of the reference signal.

Linear position sensor

Abstract: A pair of loop antennas (40, 44) mounted internal to an extensible coaxial cavity (20) respectively transmit and receive electromagnetic signals in the radio frequency range exciting a transverse electromagnetic field in the cavity (20) when the frequency of the signal corresponds to the resonant frequency of the cavity (20). The resonant frequency of the cavity (20) is primarily dependent upon the longitudinal length of the cavity (20). Therefore, a voltage controlled oscillator (36) acts under the control of a sawtooth voltage waveform of a function generator (28) to controllably deliver a variable frequency signal to the first loop antenna (40). An RF detector (47) monitors the second loop antenna (44) for an indication that the resonant frequency has been reached. At resonance a microprocessor (68) samples the output of the VCO (36) and correlates the resonant frequency to the length of the coaxial cavity (20).

Low voltage driven oscillator circuit

Abstract: An ultra low voltage energized oscillator for providing a stepped-up alternating current voltage is provided. This oscillator utilizes a field effect transistor with a high impedance network including a capacitor coupling a feedback signal from a secondary output winding to a primary input winding of a transformer.

Analog phase locked loop

Abstract: A phase locked loop for synchronizing a local digital signal with an incoming data signal is described. Parallel phase and frequency detectors compare the local and incoming signals and generate control pulse signals for controlling the frequency of a voltage controlled oscillator which generates the local digital signal. Logic circuitry is included in both the phase and frequency detectors for adjusting the generated control pulse signals in the event of detection of elongated pulse widths of the incoming data signal, indicating one of either an absence of incoming data signal or a bipolar violation in the event the data signals are ASI encoded. The phase locked loop is characterized by quick pull-in time, large pull-in frequency range, accurate clocking and low cost.

Paging device having a switch actuated signal strength detector

Abstract: A paging device includes a radio receiver (10-20) and decoding circuitry (22) for receiving an encoded transmitted signal and operates an indicator (26) to alert a user that a call has been received. A signal strength detector (30) monitors the strength of a carrier for a transmitted signal and provides a voltage level proportional to the carrier signal strength. A switch (33), when enabled, connects the voltage level from the detector (30) to a voltage controlled oscillator (32) which provides an output having a frequency proportional to the monitored strength of the carrier signal. The output of the variable frequency oscillator (32) is connected to the indicator (26) to provide the user with an indication of whether transmissions may be reliably received. The variable frequency oscillator may be replaced by a threshold device (35) to simplify the paging device, or the basic system may be provided with an averaging device (27) so that the user may select between instantaneous and average values of the strength of the monitored carrier signal. In an alterative embodiment, the paging device may be implemented using a microprocessor (23) controlled by a program stored in ROM (25) as the decoder. In this implementation, the microprocessor may be programmed to perform additional functions including computing the error rate of decoded messages, and if the error count exceeds a predetermined threshold, alerting the user of an unreliable radio link. A further refinement allows the user to monitor the error rate.

Video camera device with separate camera head and signal processing circuit

Abstract: A video camera device in which camera head and signal processing circuit are provided separately and connected to each other by cable. Camera head includes CCD, drive pulse generator for generating a drive pulse of CCD, and first VCO for generating a clock pulse. Drive pulse generator frequency divides the clock pulse signal from first VCO to produce the drive pulse. Signal processing circuit includes signal processor for processing, e.g., clamping and sampling/holding a signal from CCD, timing generator for generating a timing signal of the signal processor, and a second VCO for generating a clock pulse. Timing generator frequency divides the clock pulse signal from second VCO to generate the timing signal. The output of first VCO is supplied from camera held through cable to signal processing circuit, and to phase comparator. The output of second VCO is also supplied to phase comparator. The oscillation frequency of second VCO is controlled by the output of phase comparator such that the phase difference detected by phase comparator is made zero.

Modular unitary disk file subsystem having increased data storage capacity

Abstract: Higher data storage capacity is realized in a self contained fixed rotating disk expansion board subsystem preferably for a single electronics circuit board accessory slot of a host computer. This greater capacity, e.g. 42 megabytes of formatted storage on two 95 millimeter disks, is achieved by use of a plural zone arrangement wherein each zone contains data tracks in which user blocks are recorded and read out at a data rate unique for the zone. An improved phase locked loop within the data separator uses a separate voltage controlled oscillator for each zone and a commmon charge pump for generating control voltages applied to change the resonant frequency of all of the oscillators, An oscillator disable circuit disables every voltage controlled oscillator other than the selected oscillator, so that it is the only oscillator whose frequency is actually varied by the charge pump during readback/data separation and decode operations. A dual latch circuit extends the margin of a data window in the data separator to ensure that legitimate data bits read back from the data surface are latched for separation. A single microprocessor supervises operations of the subsystem and calculates physical sector location within each zone from logical sector location data supplied by the host computer.

Automatic calibration system for a voltage control oscillator

Abstract: A signal generator including a calibration circuit for providing periodic recalibration of the generator, including a reference frequency source for producing a fixed frequency signal. A voltage controlled oscillator (VCO) for producing a variable frequency signal in accordance with a voltage input to the VCO. An adjustable dividing network coupled to the VCO for dividing the variable frequency signal by a particular divider (N) to produce an output signal equal to the variable frequency signal divided by "N". A phase detector coupled to the reference frequency source and the dividing network for producing an error signal in accordance with the difference between the fixed frequency signal and the output signal. A filter coupled to the phase detector for producing an error voltage signal representative of the error signal. A programmable nonvolatile storage for storing a plurality of individual values representative of the plurality of frequency steps from the VCO. A converter coupled to the programmable storage for converting the stored values to a plurality of individual voltage signals. A summer coupled to the filter and the converter for summing the signals and applying the summed signals to the VCO for controlling the VCO to particular frequency steps. A comparator coupled to the phase detector for comparing the error signal to a fixed reference for producing a control signal in accordance with the comparison, and a controller coupled to the comparator and the programmable storage for reprogramming the plurality of individual values to recalibrate the frequency steps in accordance with the control signal.

BPSK demodulator and FM receiver for digital data pagers

Abstract: An FM receiver for the reception of digital data modulated on a Subsidiary Communication Authorization (SCA) subcarrier is provided with automatic tuning capability and a coherent demodulator for minimizing noise, distortion and interference. The FM receiver is tuned automatically to minimize the measured amplitude of noise and distortion at the high frequency end of the spectrum of the FM demodulator output, above the frequencies of the SCA signal. The SCA signal is tuned by a heterodyne circuit including a balanced modulator, a voltage-controlled oscillator (VCO), and a bandpass filter. The VCO is automatically tuned to maximize the measured amplitude of the SCA signal selected by the bandpass filter. For coherent detection of BPSK (Binary-Phase-Shift-Keying), the coherent demodulator is preferably and kind of data-aided Costas loop in which digital logic circuits perform phase shifting, phase detecting, a multiplying functions. The feedback of the phase error signal is preferably inhibited whenever the signal-to-noise ratio falls below the level which ensures phase-lock, for example, by inhibiting feedback whenever the amplitude of the filtered in-phase signal in the Costas loop fails to exceed a predetermined threshold level. Preferably the phase error signal is fed back through an integrating low-pass filter to control the VCO of the heterodyne circuit, and is fed back through a bandpass filter to control the oscillator of the Costas loop.

Stabilized phase locked loop

Abstract: A dual loop phase locked loop system having a secondary loop for controlling various circuit, environmental and process variations. The secondary loop is comprised of a phase comparator, a filter, a transconductance amplifier and a one-shot, wherein the output of the one-shot is fed back as an input signal for comparison with a reference signal at the input of the phase comparator. The filter generates a correction voltage which is dependent on the phase difference determined by the phase comparator, and the transconductance amplifier generates a charging current corresponding to the error voltage from the filter, wherein the charging current controls the charging of the input capacitor to the one-shot circuit for determining the duration of the pulse width of the output of the one-shot. The one-shot based loop is inherently stable since there is only one pole near the origin of the S-Plane. The primary loop is comprised of a phase comparator, a filter, a transconductance amplifier and an output means, which is a VCO and a voltage divider. The primary loop provides the actual phased locked loop of an input reference signal, however, it derives compensating analog trim information from the secondary loop. The dynamic characteristics of the primary loop are established by the reference loop, based on the reference clock frequency. Further, the loop response is controlled by the reference frequency, and is immune to process, temperature and voltage variations. In addition the loop frequency characteristics can be programmed by adjusting the reference clock.

Identical servo frequency modulated passive ring laser gyroscope

Abstract: A phase locked passive ring resonator gyroscope comprising a fixed frequency reference signal generator (Fm); a single piece body having laser and passive resonator cavities; a laser means using the laser resonator cavity responsive to a laser control signal from a laser servo for providing a single frequency light source (F0) for frequency modulating the single frequency light source to form a light source (F0) and having respective upper and lower side bands at frequencies F0+Fm and at F0-Fm; first and second voltage controlled oscillator means responsive to respective first and second control signal for frequency shifting the first and second frequency modulated ray center frequencies by a first and second variable offset frequencies to form a propagating and counterpropagating light sources; the second resonator cavity being a passive high Q evacuated cavity; a detector means for detecting a first offset frequency error signal and for detecting a second offset frequency error signal; cavity servo means responsive to the first and second offset frequency error signals from the detector means for providing, a first control signal to the first voltage controlled oscillator means for frequency shifting the first frequency modulated ray by a first variable offset frequency to maintain the propagating light beam in the second resonator at peak resonance and to provide a second control signal to the second voltage controlled oscillator means for frequency shifting the second frequency modulated ray by a second variable offset frequency (F2) to control and maintain the counterpropagating light beam (FCCW) at peak resonance; means for constantly adjusting the passive cavity path length servo signal to keep the passive cavity at peak resonance at a frequency substantially mid-range between the propagating and the counterpropagating beams; output counter means for measuring and outputting the frequency difference between the first variable offset frequency (F1) and the second variable offset frequency (F2), the measured frequency difference representing the difference in frequency due to an input gyro body rate about the gyro sensitive axis.

Compensation circuitry for dual port phase-locked loops

Abstract: Phase port gain compensating circuitry is coupled to the phase modulation summing circuit and voltage controlled oscillator (VCO) gain compensating circuitry is coupled to the frequency control terminal of the VCO. Compensator control circuitry utilizes divider ratio control information to control the characteristics of the two compensators to compensate for otherwise undesirable effects on the phase-locked loop response parameters caused by changes in the divider ratio and in the VCO gain.

MMIC 14-GHz VCO and Miller Frequency Divider for Low-Noise Local Oscillators

Abstract: An MMIC voltage-controlled oscillator and an MMIC frequency divider are developed and applied to a 14-GHz low-noise local oscillator. To obtain both wide tuning range and low pulling figure, the source-follower FET circuit is used in the voltage-controlled oscillator. A wide-band balanced mixer and a filtering amplifier are integrated in a single chip and constitute the Miller frequency divider. -The MMIC's were assembled into a 14-GHz phase-locked loop in order to demonstrate that they will operate as key components of low-noise oscillators. It is shown experimentally that even for low-Q MMIC circuitry, the carrier noise of the oscillator is reduced enough for practical purposes such as space-borne heterodyne receivers, transmitters, and radio repeaters in Ku-band satellite communication systems. Thus, prospects are bright for development of single-chip microwave low-noise oscillators.

Fast tuning control for a television system

Abstract: A fast tuning subsystem includes a tuner (24A, 24B) for selecting a channel, with a voltage controlled oscillator for determining the channel frequency the tuner selectively receives. A predictor supplies a selected predicted voltage signal from memory (56) to the oscillator to slew the channel frequency at a rapid slew rate to the frequency corresponding to the selected predicted voltage signal. An error detector (26) generates a tuning error signal indicative of the tuning error of the tuner off the frequency for the selected channel. The tuning error signal is combined (76) with the selected predicted voltage signal to provide a control signal for adjusting the channel frequency to reduce the tuning error. This feedback provides successively a relatively fast correction mode and a relatively slow station-keeping mode. The tuning subsystem automatically and from time to time updates the signals stored in the memory for respective channels.

Laser driven helium magnetometers

Abstract: A helium magnetometer includes a helium cell containing helium, preferable 4 He. A solid state laser strikes the helium cell at one end with a laser having a wave length of 1082.91 nm in the embodiment of a 4 He cell. The helium atoms precess at known frequencies for different magnetic fields. The transparency of the helium cell at 1082.91 nm with 4 He is a function of the resonance of the atoms within the helium cell. A radiation detector positioned on a second end of the helium cell opposite the end where the laser strikes detects the laser when transmitted through the helium cell and produces an electrical signal in response to the transmitted laser. The resonance of the helium cell is enhanced by a Voltage Controlled Oscillator, VCO, which provides a variable output frequency to a pair of coils positioned on the sides of the helium cell and electrically connected to the VCO to receive the variable output frequency. The pair of coils produces a variable magnetic field at the precession frequency that is mathematically related to the magnetic field that is being measured and thus enhances the precession of the atoms within the helium cell. A feedback loop includes a demodulation circuit that is electrically connected between the radiation detector and the VCO and demodulates the electrical signal from the radiation detector to produce a drive voltage for driving the VCO.

Power control device for high-frequency induced heating cooker

Abstract: A power control device for high-frequency induced heating cooker is designed to supply a constant power to the work coil regardless of any change in the input current and voltage. The control device compares the voltage detected at the input current sensor detecting the input current of the full-wave rectifier with the set voltage of the user selector and applies a control voltage to the pulse oscillator and applies the pulse oscillating signal of the pulse oscillator to the driver and makes the switching transistor rapidly turn on and off to generate a high-frequency current through the work coil. It includes a voltage sensor to detect the input and output voltages of the coil, a comparator to compare both detector voltages and to determine the drive starting point of the oscillator, a subtractor to subtract the voltage on the input side of the work coil from the set voltage of the user selector, a comparator to compare the voltage detected at the input current sensor with the normal vessel reference voltage, a transistor to cut off the control voltage applied to the pulse oscillator, a search control voltage part to produce a search control voltage of a constant level and a starting circuit part to generate an oscillation signal of a constant cycle, and a transistor turned on and off by the oscillation signal and supplies the search control voltage to the pulse oscillator in a constant period.

Clamping circuit for a PLL tuning system

Abstract: An AM Stereo receiver is described which includes an AGC having an output which indicates whether the received signal has significantly decreased in level and having a clamping circuit for controlling the voltage at the input of a VCO. The clamping circuit is further defined as having a window detector for sensing a change in the voltage at the input of the VCO according to a predetermined threshold; a selectable controller, responsive to the window detector, for adjusting the voltage at the input of the VCO; and a window reduction circuit, responsive to the output signal of the AGC, for altering the predetermined threshold to provide the controller with a more sensitive indication of a drift in the voltage at the input of the VCO. The receiver additionally includes a conventional locked loop driver for steering the VCO according to the phase of the received input signal. When the AGC output signal indicates that the signal quality of the received signal has significantly decreased in level, or when the window detector indicates that the system is tuned outside of an established narrow "tuned" window, the locked loop driver is disabled to prevent the locked loop driver from introducing a beat note into the VCO.

Extended range phaselocked loop

Abstract: An acquisition circuit in an improved phaselocked loop prevents cycle slipping by detecting and compensating an impending large phase difference between an independent incoming signal and a local comparison signal dependently related to a voltage controlled oscillator. A train of pulses is generated in progressively delayed phase relation with each cycle of the oscillator output signal. Additionally a threshold signal related to the independent signal is produced. In response to overlap of the threshold signal and individual ones of the pulses, a phase error signal is generated which controls a commutator to select individual ones of the pulses having a predetermined delay as the comparison signal, thereby generating a correcting control signal to phaselock the oscillator at a faster rate than the linear response time of a standard loop.

High-Performance GaAs MMIC Oscillators

Abstract: A number of monolithic single-ended and push-pull oscillator chips were developed for C-band through Ku-band applications. The chips were used to build both, dielectric resonator oscillators (DRO's) and voltage-controlled oscillators (VCO's) in these frequency bands. These MMIC's also have an integrated buffer amplifier at the oscillator output to provide better load isolation and power output stability. The oscillators demonstrated performance similar to conventional hybrid circuit however, the MMIC circuits provide circuit simplicity with improved reliability, decreased size, and reduced manufacturing cost.