Abstract: A tuning signal is injected into an LC tank circuit oscillator, e.g., through an impedance (either reactive, inductive, capacitive and/or resistive) to tune the phase and/or frequency of the LC tank circuit oscillator. A negative resistance is included in parallel with the LC tank circuit oscillator to compensate for losses in the LC tank circuit, and a bias signal is provided to power the operation of the LC tank circuit. Multiple LC tank circuit oscillators may be used to provide stable multiplied or divided frequencies. In another embodiment, the nominal frequency of the LC tank circuit oscillator may be adjusted using a varactor or other voltage-controlled element in the LC tank circuit oscillator under the control of, e.g., the output of a separate PLL loop including another LC tank circuit oscillator. In one application, the injection tuned LC tank circuit forms a clock recovery cell using a clock signal embedded in a NRZ (Non Return to Zero) pseudo-random data stream.

Abstract: The present invention proposes a multiple-push oscillator for providing a high-frequency signal. The multiple-push oscillator combines N (at least 3) fundamental oscillators. Through the design of circuit connection, the N fundamental oscillators will operate at odd modes with phase differences of 360/N degrees between their output currents to obtain an output signal of frequency at least three times as large as that of the fundamentals. Therefore, a high-frequency signal source can be more easily designed by the present invention. Moreover, the present invention has the characteristics of high transistor gain and high resonator Q factor.

Abstract: A voltage controlled crystal oscillator (VCXO) 25, for example, as used in a mobile communications terminal 23, has its output frequency Fref stabilised against temperature drift using frequency correction information received, for example, in a downlink signal 35 from a base station 33. A controller 31 uses the frequency correction information to produce a digital value 39 which is supplied to a DAC 29 which controls the output frequency of the VCXO 25. While the frequency is being stabilised in this manner, compensation values are determined based on the DAC value 39 and temperature values from a temperature ADC 45, and stored in memory 41. When the correction information ceases to be available, the compensation values from the memory 41 are used to compensate for temperature fluctuations. Each compensation value corresponds to a linear temperature region, and relates to the gradient for that temperature region.

Abstract: A radio frequency transmitter circuit including a user input switch for producing an input signal, an oscillator for producing a frequency signal having a first frequency, an antenna connected to the oscillator for broadcasting the frequency signal, a coupling circuit disposed a predetermined distance from the antenna, and a microprocessor for enabling the oscillator and activating the coupling circuit in response to the input signal. When the coupling circuit is activated, a reflected impedance, derived from a change in inductance, is reflected from the coupling circuit upon the antenna thereby shifting the frequency signal to a second frequency. Sequentially activating and deactivating the coupling circuit modulates the frequency signal.

Abstract: In a microwave/millimeter-wave injection locked oscillator, an oscillation circuit (15) has an active element section (1), a resonant circuit (4) connected with the active element section (1) at one side thereof and resonating at predetermined frequency f, and a harmonic output circuit (3) connected with the active element section (1) at the other side thereof and providing a signal having an nth (n: an integer ≧2) harmonic component of the signal having the frequency f from the resonant circuit (4). An injection circuit (16) is connected with the oscillation circuit (15) via an input terminal (7). A reference signal having a frequency component of f/m (m integer) is injected through the input terminal (7) into the resonant circuit (4), whereby signals in the resonant circuit (4) are frequency-locked to the reference signal. The injection circuit (16) can use a crystal oscillator for a stable low frequency.

Abstract: A tuning signal is injected into an LC tank circuit oscillator, e.g., through an impedance (either reactive, inductive, capacitive and/or resistive) to tune the phase and/or frequency of the LC tank circuit oscillator. A negative resistance is included in parallel with the LC tank circuit oscillator to compensate for losses in the LC tank circuit, and a bias signal is provided to power the operation of the LC tank circuit. The tuning signal may be, e.g., an AC signal or a data signal. The tuning signal is injected into the LC tank circuit using capacitors, resistors, FET or bipolar transistors, and/or inductors. Multiple LC tank circuit oscillators may be used to provide stable multiplied or divided frequencies. In this case, the output of one LC tank circuit oscillator may be used to tune another LC tank circuit oscillator.

Abstract: A differential oscillator based on a first Colpitts oscillator and a mirror image Colpitts oscillator that is coupled to the first Colpitts oscillator. This differential oscillator outputs differential voltage signals that are about 180 degrees out of phase. The differential oscillator may also be adapted to form a voltage controlled oscillator (VCO) such that the differential voltage signals output by the VCO can be varied. A transceiver for telecommunication devices such as cellular phones may use differential oscillators to generate a carrier signal on which a voice or data signal is modulated and the same differential oscillators to assist isolation of the voice or data signal from received signals.

Abstract: An adjustable frequency oscillator with a wide tuning range which can be voltage or current controlled. A maximum tuning per feedback current is obtained by phase shifting a feedback signal by approximately 90 degrees with respect to the oscillating output signal, which is internally generated by the adjustable frequency oscillator. Over the frequency range of operation, the oscillation frequency of the oscillating output signal is linearly controllable. The adjustable frequency oscillator is also implemented as a ring oscillator and/or an oscillator with ranging.

Abstract: A multifunction high frequency integrated circuit structure and circuit configuration includes a resonator or oscillator circuit coupled to a buffer amplifier by way of a stripline coupler. The resonator circuit includes an input terminating region which is coupled to three input terminating ports. A first one of the input terminating ports is coupled directly to the resonator for either being electrically connected to a selected signal source or load, a second one of the input terminating ports is electrically connected to either a fixed or variable potential source, and the remaining input terminating port is coupled to the resonator input terminating region through another stripline coupler, and is intended to be electrically connected to another selected signal source.

Abstract: Two or more equal amplitude periodic output signals which are mutually shifted in phase by an integer fraction of 360 degrees, such as 90°, are generated by injection locking a ring type oscillator circuit arrangement with a periodic low phase noise signal source. More particularly, a first ring oscillator is injection locked by a low phase noise signal source, one having a noise characteristic which meets the GSM radio standard of at least −132 dBc/Hz at a 3 MHz offset. An identical second ring oscillator is then driven with the output of the first ring oscillator. In one circuit configuration, an even numbered, e.g., a four stage ring oscillator is injection locked to a low-phase noise oscillator having a predetermined noise specification which is application specific and wherein a second even numbered stage, e.g., a four stage ring oscillator is coupled to the first ring oscillator. In a second circuit configuration, a first odd numbered, e.g.

Abstract: An AC tuning signal is injected into an LC tank circuit oscillator through an impedance (either reactive, inductive, capacitive and/or resistive) to tune the phase and/or frequency of the LC tank circuit oscillator. A negative resistance is included in parallel with the LC tank circuit oscillator to compensate for losses in the LC tank circuit, and a bias signal is provided to power the operation of the LC tank circuit. The AC tuning signal may be injected into the LC tank circuit using capacitors, resistors, FET or bipolar transistors, and/or inductors. Multiple LC tank circuit oscillators may be used to provide stable multiplied or divided frequencies. In this case, the output of one LC tank circuit oscillator may be used to tune another LC tank circuit oscillator. In another embodiment, the nominal frequency of the LC tank circuit oscillator may be adjusted using a varactor or other voltage-controlled element in the LC tank circuit oscillator under the control of, e.g.

Abstract: A receiving apparatus has a clock frequency generating circuit comprising in a first embodiment a low cost oscillator whose frequency is higher than the wanted clock frequency and in a second embodiment a low cost oscillator whose frequency can be higher or lower than the wanted clock frequency. By means of subtracting pulses from (first embodiment) or adding/subtracting pulses (second embodiment) to/from the output of the low cost oscillator, a clock frequency is generated which is stable within a specified tolerance range.

Abstract: An oscillation output generating circuit outputs a voltage V0 as an oscillation output, and a first comparing circuit compares V0 with a constant voltage V1, while a second comparing circuit compares V0 with a constant voltage V2 (<V1). In response to outputs from the first and second comparing circuits, a state maintaining circuit controls the raising/dropping of V0 through the oscillation output generating circuit. When a synchronizing pulse for synchronous oscillation is not inputted, self-advancing oscillation is started, and synchronous oscillation is started otherwise. When the synchronizing pulse is in an active state, a nullifying circuit inhibits transmission of an output from one of the first and second comparing circuits to the state maintaining circuit, whereas the nullifying circuit allows the above transmission when the synchronizing pulse is in an inactive state.

Abstract: In plural oscillation systems each of which can be described by the van der Pol equation, each oscillation system is reciprocally connected with at least one oscillation system other than the own oscillation system by a coupling factor to realize automatically the phenomenon of synchronization of the respective oscillation systems to enable spontaneous tuning of the entire system. A self-excited oscillation of an oscillation system prescribed by a van der Pol equation is controlled on/off by varying an applied voltage as a variable.

Abstract: A simple carrier recovery circuit capable of accurately detecting and synchronizing an incoming carrier frequency without the use of a phase locked loop (PLL) is provided. Instead of a PLL, the carrier recovery circuit includes an injection locked oscillator. The injection locked oscillator includes an input for connection to the received modulated signal. The gain of an inverter stage of a amplifier in the injection locked oscillator is modulated by the received modulated signal using an injection transistor connected between the power source and the output of the inverter stage. The gate of the injection transistor receives a signal corresponding to the received modulated signal.

Abstract: A high frequency anharmonic oscillator provides a broad band chaotic oscillation with a noise-like spectra. The oscillator output signal is suitable for modulation by data providing for improved secure communication. The chaotic oscillator is based upon a forced second order Duffing equation that is tolerant of delay in the feedback path for high frequency operation.

Abstract: An oscillator includes four identical cells each producing a phase shift of 90 degrees. The output signal from one cell is applied to the input of the next cell, and with the cells looping back to themselves. Each cell includes a current amplifier and a parallel inductance-capacitance resonant circuit configured such that the output current from one cell is a fraction of the capacitive current of the parallel resonant circuit. This causes the 90.degree. phase shift between the input and output currents of each cell.

Abstract: Phase noise in an RF oscillator is significantly reduced by loosely couping another quieter RF oscillator having noise patterns uncorrelated to the first RF oscillator so that it frequency locks with the first RF oscillator. The coupling is increased until a significant reduction in phase noise occurs at high coupling levels where the first RF oscillator displays phase noise similar to the the second RF oscillator.

Abstract: An oscillation circuit that improves the duty controllability by cross-coupling ring oscillators that are comprised of current inverters. The sources of current supply circuits 4a-4c and 6a-6c are connected to a power supply and their drains are connected to terminals A in corresponding current inverters, respectively. Each of the gates of those current supply circuits receives an output of a current inverter corresponding, one to one, to a current inverter to which the current supply circuit is connected.

Abstract: In a method of calibration of a voltage controlled oscillator (VCO), the VCO (100) provides an output signal which is used to drive a dividing oscillator (10) such as a relaxation oscillator (RO). The RO has at least two states, one in which the RO provides an output signal which has a first frequency that is related to the VCO output signal by a first ratio (e.g. 1/N) and one in which the relaxation oscillator provides a RO output signal which has a second frequency that is related to the VCO output signal by a second ratio (e.g. 1/(N+1)). By measuring the first and second frequencies (and knowing the relationship between the first and second ratios), the VCO frequency is calculated and stored (110). Several VCO frequencies can be calculated and stored for several applied voltages. As a result the VCO can be driven to any selected frequency in the calibrated range and can be used to provide an injection frequency for a radio.

Abstract: An electromagnetic radiation reflection amplifier capable of amplifying cw or pulsed signals has a pair of cw oscillators operated under injection locking conditions. Diversion of oscillator power to a separate signal path during the off time of the input pulse is achieved through purely passive means; no active control devices are utilized. The device can be implemented for amplification of microwave, millimeter wave or optical signals. The amplifier comprises a 180-degree hybrid coupler, a matched pair of cw oscillator modules, a waveguide discontinuity, a waveguide termination, and an optional signal input element. For a magic-tee hybrid coupler, the cw oscillator modules are mounted on the ports of the symmetrically positioned waveguide arms and the waveguide discontinuity is located within either the sum arm or difference waveguide arm intermediate its ends.

Abstract: A dual-multivibrator circuit using a pair of mutually triggering multivibrator sections is connected to operate in a free-running mode when no external synchronization signal is applied to the circuit input, and in synchronism with a master pulse train of substantially the same pulse repetition rate when such a master pulse train is applied to the circuit input.

Abstract: In a variable delay circuit including a high-speed clock generator receiving a trigger signal and outputting a pulse signal after a desired time interval upon rising of the trigger signal and a coarse delay signal generator, the high-speed clock generator includes a rising edge detector receiving the trigger signal, detecting a rising edge of the trigger signal, and outputting an edge detecting pulse having a time interval, and an asynchronous reset oscillator receiving the edge detecting pulse, being reset upon rising of the edge detecting pulse, and generating a high-speed clock upon falling of the edge detecting pulse. The high-speed clock generator of the variable delay circuit is realized without using analog circuits. Further, since the high-speed clock generator includes no PLL, it is not necessary to provide analog circuits, such as charge pump and VCO, in a digital LSI and, therefore, special considerations for the analog circuits are eliminated.

Abstract: A oscillator having two synchronized oscillator rings is described. Synchronization is accomplished by circuitry connected between the outputs of two aligned stages in coupled oscillator rings, the circuitry being operable to maintain outputs of the stages 180.degree. apart in phase.

Abstract: A voltage-controlled oscillator has ring oscillators R1, R2 and R3 which have three amplifier elements A1-A3, A4-A6 and A7-A9 respectively which are connected in the form of a ring. The way of connecting with the respective amplifier elements A10 to A18 is as follows: First, optionally selecting two output terminals from the 3.times.3 amplifier elements which form three ring oscillators, wherein the two output terminals are not selected from the input and output terminals of one amplifier element, and wherein the two output terminals are not selected from the output terminals belonging to the same ring oscillator. Next, connecting the input and output terminals of one of the amplifier elements A10 to A18 to the optionally selected two output terminals. Then repeating the above procedures one or more times to form a network between the ring oscillators R1 to R3. C1 to C9 are nodes for the connections.

Abstract: In a multiphase output oscillator a number of serially coupled oscillator circuits is organized in a loop. Each particular oscillator circuit is coupled to its serial successor in the loop, to provide adjustment of the phase of an oscillation signal of the successor oscillator circuit dependent upon a difference between the phase of the oscillation signal in the successor and the phase of an oscillation signal in the particular oscillator circuit. None of the oscillator circuits will oscillate freely: as each oscillator will adjust its successor all the way around the loop. Indirectly, each oscillator circuit thus influences all of the other oscillator circuits and ultimately over itself. The multiphase output oscillator as a whole will oscillate in a collective mode of oscillation wherein all oscillator circuits oscillate at the same frequency. Successive oscillator circuits along the loop will oscillate at respective fractions of the full oscillation period delayed from each other.

Abstract: A clock distribution system and clock interrupt system for an integrated circuit device. Ignoring effects associated with the matched stages, the present invention includes a clock distribution and interrupt system for providing clock signals with less than 100 picoseconds of skew to various components of an integrated circuit device. The present invention utilizes several stages of drivers to evenly supply the distributed clock signals and each stage has RC matched input lines. The present invention advantageously locates the matched stages and clock drivers within the power supply ring of the integrated circuit located on the periphery of the microprocessor topology. This is done in order to better predict the topology surrounding these lines to match the capacitance of these lines. Further, this metal level offers a larger width dimension line (since as a top layer it may be thicker) having less resistance per unit area and also generally avoids spatial competition with other IC components and circuitry.

Abstract: The voltage-controlled oscillator according to the invention has a plurality of first amplifier elements 100 and a plurality of phase correctors 101. Each of the first amplifier element 100 is provided with a pair of input signal lines, a pair of output signal lines and one or more control signal line 104 and can function as a differential amplifier and control the delay time for which a differential signal is transmitted from the pair of input signal lines to the pair of output signal lines by the control signal of the control signal line 104.

Abstract: An apparatus and method are provided for increasing the Q-value of an oscillator so that a net gain in the stability of the oscillators is obtained. In the apparatus and method, a plurality of units, which each include a passive frequency-selective circuit and an active amplifier, are cascaded and the required isolation between the passive frequency-selective circuits is maintained by the active amplifier acting as a buffer. As a result, interaction and loading is prevented between the passive frequency-selective circuits so that the net gain in the stability of the oscillator is achieved because the Q-value of the oscillator is increased.

Abstract: An injection-locked oscillator having a non-reciprocal four-port network with a pair of input ports (1, 2) and a pair of output ports (3, 4) in which the signal transfer path from a first input port (1) to a first output port (3) is non-reciprocal, the signal transfer path from a second input port (2) to a second output port (4) is non-reciprocal, the signal transfer path from a second input port (2) to a first output port (3) is non-reciprocal, and an amplifier with the input port coupled with said first output port and the output port coupled with said second input port, is locked to an injection signal applied to said first input port and provides oscillation output to said second output port (4). The circuit between the first input port (1) and the second input port (2), and the circuit between the first output port (3) and the second output port (4) are isolated. The present oscillator is implemented in a small IC chip, and has feature to be injection-locked in wide frequency band.

Abstract: A microwave generator has its microwave frequency optically phase-locked by means of a reference frequency of a reference signal, wherein at least one portion of an electronic circuit arrangement is supplied with an optical reference carrier signal modulated with the reference frequency. The circuit arrangement (16) includes two components (Q1 to Q6; Q10, Q11) based on different semiconductor types which are chosen so that one of them, the first component, which is of a first semiconductor type, optically responds to the reference carrier signal (3) and, thus, to the reference frequency (f.sub.1 Mod1. . . Modn) for achieving synchronization, and that--independently of the response of the first component--the other, second component, which is of a second semiconductor type, responds to an optical control carrier signal (6) differing in frequency from the reference carrier signal (3).

Abstract: A dual-gate self-oscillating mixer FET that is injection-locked from a remote LO frequency source. The dual-gate FET having a feedback circuit connected between the first gate port and the drain port that is tuned so that the FET can oscillate within a frequency range including a predetermined LO frequency. The FET having a remote synchronization circuit electrically connected to the FET first gate port to inject the predetermined LO frequency therein and lock the FET oscillation to that LO. Accordingly, the dual-gate FET mixes RF energy input to the second gate port with the locked LO injected in the first gate port and outputs the desired intermediate frequency through the drain port.

Abstract: An injection-locked variable-frequency high-power microwave frequency generator includes an injection source, a circulator, and an oscillator. The circulator includes an injection port to the injection source, an oscillator port to the oscillator, and a transmission port. The circulator directs the injection signal from the injection source into the oscillator and directs the oscillator output out the transmission port. The oscillator includes an IMPATT diode and a microstrip matching circuit. The matching circuit provides the sufficient conditions for broadband (9.1-9.5 GHz) oscillation of the diode. To this end, the matching circuit provides three resonators having three different but closely coupled resonant frequencies. The matching circuit also serves as a transformer, providing impedance matching to the circulator. A high-power output can be chirped or otherwise controlled by electronic control of the injection frequency.

Abstract: A direct digitally synthesizer-based, injection locked oscillator includes a direct digital synthesizer for generating a digitally synthesized signal at frequency f.sub.0, an analog oscillator circuit for generating an analog signal at frequency f.sub.1 and a filter coupled to the direct digital synthesizer for filtering the digitally synthesized signal to provide a signal at frequency Nf.sub.0. N may be an integer from 1 to 10. Also included is a coupler to couple the filtered, digitally synthesized signal into the analog oscillator to lock the frequency of the analog output signal to the frequency of the digitally synthesized signal such that the frequency f.sub.1 is equal to the frequency Nf.sub.0. The coupler also electrically couples the analog signal from the analog oscillator circuit to a second filter to filter the analog signal. An amplifier electrically coupled to the second filter amplifies the filtered signal to provide an analog oscillator output signal.

Abstract: The coupling of optical signals to the active region of a FET having a wide source to drain spacing via an optical fiber and material having an index of refraction matching that of the fiber or the FET so as to increase the locking range when the FET is part of an oscillator circuit or to increase the change in the electrical gain of the FET caused by a change in the optical energy if the FET is an amplifier.

Abstract: A signal generator which includes two matched ring oscillators, and feedback gates which cross-couple each ring oscillator to the other. That is, in each oscillator, a first node gates a coupling transistor which connects a second node (complementary to the first node) across to drive the first node of the other oscillator.

Abstract: An optically controlled oscillator circuit having an oscillator field eff transistor (FET) and having a separate light sensing quench FET. The optically controlled oscillator circuit includes, a light source, a control connected to the light source, an optic fiber having an end coupled to the light source, a quench field effect transistor (FET) coupled to a second end of the optic fiber, an oscillator FET, each FET being a GaAs multi-finger FET having drains and sources and gates, and a circuit connected in series circuit through the drains and sources of the quench FET and oscillator FET across a source of positive voltage.

Abstract: A circuit device for phasing an oscillator, which comprises a multivibrator having a transistor pair with the emitters coupled through a capacitor, comprises a normally open electronic switch controlled by a drive signal to close and inhibit the oscillator. This switch connects a voltage divider to the base of a transistor connected to one of the emitters to interrupt the loop positive feedback of the oscillator upon the voltage across the capacitor reaching a predetermined value.

Abstract: An optically controlled resonant tunnel diode oscillator assembly having a esonant tunnel diode (RTD) which, when voltage biased, oscillates at a free running frequency; an optical signal delivery system, such as a light intensity modulator connected to optical fibers; and other oscillator circuitry which one skilled in the art could readily adapt to the concepts of the present invention. In operation, the free running oscillation of the RTD can be frequency modulated or can be intensity locked to the intensity modulated optical signal delivered via the optical signal delivery system.

Abstract: Line terminal groups are redundantly present for reliability reasons. The connecting through of the input lines to the switching matrix network can thereby proceed via different signal paths. In order to avoid disturbances during switch-over between signal paths, the appertaining interfaces are provided with compensation memories. The data contained in the compensation memories are written in or read out in a phase-synchronized and frame-synchronized manner with a uniform clock. The uniform clock is acquired from the electronic switching device base clock of the system. Due to transient time distortions and component tolerances, the base clock must be regenerated with the circuit arrangement of the invention before it is applied to the compensation memories.

Abstract: A source for generating energy in the microwave region to a load comprising a transmission line, a semiconductor switch connected between said transmission and said load, said switch being operable, in its open state, to sustain a voltage corresponding to the average maximum electric field physically sustainable by the switch and, in its closed state, to sustain the maximum current density J equal to Wd.sub.3, where W is the width of the switch and d.sub.3 its thickness to thereby supply maximum power to the load and maximum switching speed.

Abstract: An oscillator including an oscillator input node for receiving an oscillator input analog signal, an oscillator output node for providing a train of output pulses having a frequency related to the magnitude of the input analog signal, a trigger gate component connected between the input node and the output node and having a low threshold and a high threshold, the gate component being in a path between the input and output without other active components and having a low input current in the range of 1 uA or less, a feedback switch connected in parallel to the trigger gate component and having a switch turn on threshold such that the switch is turned on to conduct current when the trigger gate is in one output state and is turned off when the trigger gate is in the other output state, and capacitance between a reference voltage and the input node so that the voltage at the input node ramps from one threshold to the other at a rate dependent on the input current.

Abstract: A source for generating microwaves using sequential switching of cascaded TEM transmission lines of arbitrary lengths charged to arbitrary voltages where the delay between any two switches is equal to or greater than the temporal length of the transmission line separating them, the first switch activated being the one closest to the load. The source uses an optimized transmission line and switch geometry which yields the highest possible power flow. Various folded configurations of the source which provides added compactness and simplified energizing are also disclosed.

Abstract: This invention provides an improved method for synchronizing a slave oscillator with a master oscillator. The slave includes two counters designated Reference and System, driven by its oscillator; the master includes a System Counter driven by its oscillator. The master sends a reset signal to the slave, simultaneously resetting its System Counter. Periodically, the master sends to the slave a synchronization signal, which signal is generated at predetermined intervals based upon the master's System Counter. Upon receipt of the reset signal, the slave resets its counters. Later, upon receipt of the synchronization pulse, the slave modifies the value of its System counter based upon the closest multiple of the expected count value for the synchronization signal interval. The Reference Counter is not synchronized and runs free.

Abstract: A clock recovery circuit includes a tuned-tank circuit for receiving RZ data signals, a comparator for converting an analog clock signal produced by the tuned-tank circuit to a digital clock signal, and a positive feedback of the digital clock signal to the tuned-tank circuit for self-regenerating the clock signal.

Abstract: A timing recovery apparatus for a burst mode communication receiver. The apparatus provides for optimum sampling and digitizing of received data at a plurality of data rates. In particular, a VCO is phase-locked to a local frequency reference prior to data being received. A reference timing preamble transmitted prior to the data is filtered and fed to the VCO causing it to injection lock such that the VCO becomes phase aligned with the preamble. The VCO is then permitted to "free run" during data transmission and continues to operate at substantially the same frequency. A synchronous divider and multiplexer, responsive to the VCO, allows selection of sampling clocks for the plurality of data rates. The divider is forced to a known state during VCO injection locking, to assure that the sampling clocks have maintained the proper phase for optimal sampling at the corresponding data rate. Further, means is provided to monitor the frequency of the VCO.

Abstract: A microwave frequency discriminator, i.e. an electronic device for directly transforming frequency modulation on a microwave carrier into a demodulated lower frequency signal. The discriminator is similar to a Travis discriminator and includes an inlet microstrip line, two resonant circuits (R.sub.1, R.sub.2) constituted by dielectric resonators and coupled to said inlet microstrip line to receive the modulated microwave signal, two outlet microstrip lines coupling each resonator to a respective microwave detector circuit, said detector circuits including loads (r.sub.1, r.sub.2) in series-opposition in the manner of a Travis discriminator. An amplitude limiter suitable for connection to the discriminator includes a three-port circulator having a first port for receiving microwaves, a third port for providing microwaves to the discriminator, and a second port intermediate the first and third ports in the direction of circulation, the second port being coupled to a synchronized oscillator.

Abstract: An optical injection locking oscillator is comtemplated having a tuning device. The tuning device generates a DC voltage proportional to the resonant frequency of a modulated light used to injection lock the free running oscillator. The DC voltage is applied to a varactor capacitor within the oscillator to bring the frequency of oscillation within a close proximity to the modulating frequency of the light. This facilitates injection locking, whereas frequencies of oscillation outside a certain locking range will not facilitate injection locking. The modulated light then locks the oscillator into a desired resonant frequency. A second embodiment contemplates using a YIG oscillator regulated by a DC current generated within the tuning device.

Abstract: An oscillator in which a selected portion of selected oscillatory cycles can be synchronized with a corresponding selected feature occuring in an externally supplied signal using logic gates with feedback thereabout and an input capacitance.

Abstract: A wide deviation tracking filter is provided which has the input signal to be tracked applied to a low frequency phase-locked loop circuit which performs coarse filtering of the phase noise on the input signal. A digital phase shifter is connected in series in the low frequency phase-locked loop and produces a pair of quadrature clock signals which are at the frequency of the input signal and at half the frequency of the output of the voltage control oscillator of the low frequency phase-locked loop. The pair of quadrature signals are connected to an image reject circuit. The image reject circuit is connected in series in the loop of a high frequency phase-locked loop which operates at a much higher frequency than the low frequency phase-locked loop and performs the function of further filtering the phase noise on the input signal to provide an output signal having ultra-low phase noise.