Abstract: An endoscope apparatus includes an identification unit provided in each of a plurality of optical adaptors, an MMA connected in parallel to the identification unit, an MMA drive circuit that is provided in a main body portion and applies a drive signal for driving the MMA through a pair of conductive wires, a sine-wave generation circuit that is provided in the main body portion and applies an alternating signal to the identification unit through a pair of conductive wires in a state where any one of the plurality of optical adaptors is mounted at a distal end portion, and CPU that is provided in the main body portion and measures an input impedance of the pair of conductive wires at a frequency of the alternating current signal to perform individual identification of the optical adaptor mounted at the distal end portion based on a measurement result.

Abstract: Quadrature oscillator circuitry, comprising: a first differential oscillator circuit having differential output nodes and configured to generate a first pair of differential oscillator signals at those output nodes, respectively; a second differential oscillator circuit having differential output nodes and configured to generate a second pair of differential oscillator signals at those output nodes, respectively; and a cross-coupling circuit connected to cross-couple the first and second differential oscillator circuits. The cross-coupling circuit may comprise a pair of cross-coupled transistors.

Abstract: Systems and methods for digital synthesis of an output signal using a frequency generated from a resonator and computing amplitude values that take into account temperature variations and resonant frequency variations resulting from manufacturing variability are described. A direct frequency synthesizer architecture is leveraged on a high Q resonator, such as a film bulk acoustic resonator (FBAR), a spectral multiband resonator (SMR), and a contour mode resonator (CMR) and is used to generate pristine signals.

Abstract: Embodiments of clock circuits disclosed herein include a crystal oscillator circuit, an injection oscillator coupled to kick-start the crystal oscillator circuit and a digital frequency calibration circuit coupled to recalibrate the injection oscillator. The crystal oscillator circuit is configured to generate a clock signal at a resonant frequency. The injection oscillator is coupled to supply an oscillation signal at an injection frequency to the crystal oscillator circuit to reduce a start-up time of the crystal oscillator circuit. The digital frequency calibration circuit is coupled to receive the resonant frequency and the injection frequency as inputs, and configured to supply a digital control signal to the injection oscillator to set the injection frequency of the injection oscillator substantially equal to the resonant frequency of the crystal oscillator circuit. Methods are provided herein to recalibrate the injection frequency of an injection oscillator over time, temperature and/or supply voltage.

Abstract: A high-power transmitter with a fully-integrated phase Iocking capability is disclosed and characterized. Also provided herein is a THz radiator structure based on a return-path gap coupler, which enables the high-power generation of the disclosed transmitter, and a self-feeding oscillator suitable for use with the transmitter.

Abstract: Systems and methods for digital synthesis of an output signal using a frequency generated from a resonator and computing amplitude values that take into account temperature variations and resonant frequency variations resulting from manufacturing variability are described. A direct frequency synthesizer architecture is leveraged on a high Q resonator, such as a film bulk acoustic resonator (FBAR), a spectral multiband resonator (SMR), and a contour mode resonator (CMR) and is used to generate pristine signals.

Abstract: Aspects of the disclosure are directed to reducing clock-ungating induced voltage droop by determining a maximum frequency value associated with an output clock waveform; modulating a clock frequency of the output clock waveform for a first time duration based on a first programmable mask pattern or a first Boolean function; and determining if either the first programmable mask pattern or the first Boolean function should be changed. In accordance with one aspect, a voltage droop mitigation circuit includes a control logic for receiving an input clock waveform and a clock enable signal waveform and for outputting a gated clock enable signal waveform; a latch coupled to the control logic, the latch for holding a state of the gated clock enable signal waveform and a AND gate coupled to the latch, the AND gate for outputting an output clock waveform.

Abstract: Methods and an apparatus related to generating parameters and guidelines used in the manufacture of semiconductor IC devices are described. A method includes measuring a first oscillating signal produced by a first ring oscillator that includes a first interconnect provided in a first interconnect layer of an IC, selecting a first mode of operation for a second ring oscillator circuit that includes a second interconnect disposed in alignment with the first interconnect, selecting a second mode of operation for the second ring oscillator circuit, and determining one or more characteristics of the first interconnect based on a difference in frequency of the first oscillating signal produced when the second ring oscillator circuit is operated in the first mode and frequency of the first oscillating signal when the second ring oscillator circuit is operated in the second mode.

Abstract: Automatic calibration circuits for operational calibration of critical-path time delays in adaptive clock distribution systems, and related methods and systems, are disclosed. The adaptive clock distribution system includes a tunable-length delay circuit to delay distribution of a clock signal provided to a clocked circuit, to prevent timing margin degradation of the clocked circuit after a voltage droop occurs in a power supply supplying power to the clocked circuit. The adaptive clock distribution system also includes a dynamic variation monitor to reduce frequency of the delayed clock signal provided to the clocked circuit in response to the voltage droop in the power supply, so that the clocked circuit is not clocked beyond its performance limits during a voltage droop. An automatic calibration circuit is provided in the adaptive clock distribution system to calibrate the dynamic variation monitor during operation based on operational conditions and environmental conditions of the clocked circuit.

Abstract: Apparatus are provided for voltage-controlled oscillators and related systems. An exemplary voltage-controlled oscillator includes an active-circuit arrangement that facilitates generation of an oscillating signal, and a resonator arrangement capacitively coupled to the active-circuit arrangement to influence an oscillation frequency of the oscillating signal based on a difference between a first control voltage and a second control voltage.

Abstract: A voltage controlled oscillator (VCO) with low phase noise and a sharp output spectrum is desirable. The present disclosure provides embodiments of LC tank VCOs that generate output signals with less phase noise compared with conventional LC tank VCOs, while at the same time limiting additional cost, size, and/or power. The embodiments of the present disclosure can be used, for example, in wired or wireless communication systems that require low-phase noise oscillator signals for performing up-conversion and/or down-conversion.

Abstract: A transceiver includes a phase lock loop (PLL) and a clock data recovery circuit (CDR). The phase lock loop generates a first level control signal. The clock data recovery circuit, coupled to the phase lock loop, locks an incoming data signal to generate a data recovery clock according to a second level control signal. Wherein the clock data recovery circuit receives the first level control signal to further control a frequency range of the data recovery clock.

Abstract: This invention compensates for the unintentional magnetic coupling between a first and second inductor of two different closely spaced inductors separated by a conversion circuit. A cancellation circuit formed from transistors senses the magnetic coupling in the first inductor and feeds a current opposite to the induced magnetic coupling captured by the second inductor such that the coupled magnetic coupling can be compensated and allows the first and second inductors to behave independently with regards to the coupled magnetic coupling between the first and second inductors. This allows the distance between the first and second inductors to be minimized which saves silicon area. In addition, the performance is improved since the overall capacitance in both circuits can be decreased. This cancellation technique to reduce the magnetic coupling between two closed placed inductively loaded circuits allows the design of a more compact and faster performing circuit.

Abstract: A method for adjusting an oscillator clock frequency, comprising: providing a first oscillator, applying a first setpoint value to the first oscillator, determining a first oscillator frequency value within a first time frame, providing a second oscillator, applying a second setpoint value to the second oscillator, determining a second oscillator frequency value within a second time frame, determining a new frequency setpoint value from the first and second frequency values, the first and second setpoint values, and a desired frequency value, and applying the new frequency setpoint value to one of the first and second oscillators.

Abstract: A wideband frequency generator has two or more oscillators for different frequency bands, disposed on the same die within a flip chip package. Coupling between inductors of the two oscillators is reduced by placing one inductor on the die and the other inductor on the package, separating the inductors by a solder bump diameter. The loosely coupled inductors allow manipulation of the LC tank circuit of one of the oscillators to increase the bandwidth of the other oscillator, and vice versa. Preventing undesirable mode of oscillation in one of the oscillators may be achieved by loading the LC tank circuit of the other oscillator with a large capacitance, such as the entire capacitance of the coarse tuning bank of the other oscillator. Preventing the undesirable mode may also be achieved by decreasing the quality factor of the other oscillator's LC tank and thereby increasing the losses in the tank circuit.

Abstract: The present disclosure provides a tunable signal source having a plurality of oscillator cores having a coupling input, a coupling output, and a power output that is common to each of the plurality of oscillator cores. Also included is a plurality of tunable phase shifters wherein corresponding ones of the plurality of tunable phase shifters are communicatively coupled between the coupling input and the coupling output of corresponding ones of the plurality of oscillator cores, thereby forming a loop of alternating ones of the plurality of oscillator cores and alternating ones of the plurality of tunable phase shifters.

Abstract: A design for an oscillator, and a PLL incorporating such an oscillator, which takes up little physical area but maintains a large tuning range and low phase noise. Two LC-tanks are nested and switched. Through tuning the inactive tank, the range of the active tank may be increased and finer tuning becomes possible.

Abstract: An integrated circuit device for generating an output frequency includes a master oscillator and a slave oscillator formed on an integrated circuit substrate. The master oscillator utilizes a bulk acoustic wave resonator that provides a reference frequency source to the device. The frequency of the slave oscillator is periodically adjusted with respect to the reference frequency source and provided as an output. The master oscillator is periodically enabled to adjust the slave oscillator. Additional automatic temperature compensation is enabled as necessary.

Abstract: A voltage-controlled oscillator (VCO) module including a first VCO unit, a second VCO unit, and a matching circuit is provided. The first VCO unit includes a first terminal and a second terminal and generates a first oscillator signal. The second VCO unit is coupled to the first VCO unit and generates a second oscillator signal. The matching circuit is coupled between the first VCO unit and second VCO unit. The matching circuit includes a plurality of inductor modules respectively coupled between the first terminal of the first VCO unit and the second VCO unit, between the first terminal and the second terminal of the first VCO unit, and between the second terminal of the first VCO unit and the second VCO unit. Furthermore, a method for generating oscillator signals is also provided.

Abstract: Embodiments of the present invention relate to a self injection locked voltage controlled oscillator arrangement, a pair of coupled first and second voltage controlled oscillator devices are arranged on a chip, an amplifier device is arranged on the same of the refection type chip, and an off-chip delay line is arranged with one terminal connected to an output terminal of the coupled first and second voltage controlled oscillator devices, and on terminal adapted to reflect a signal from the output terminal, the amplifier device being arranged to amplify an injection signal from said output terminal and to supply the amplified injection signal to one of said first and second voltage controlled oscillation devices to provide a VCO arrangement that exhibits low phase noise and a small size.

Abstract: A tunable Injection-Locked Oscillator (ILO) having a wide locking range is used in a Local Oscillator (LO) of a wideband wireless transceiver to generate differential signals. The ILO includes a resonator with an adjustable natural oscillating frequency. In one example, the ILO is part of a quadrature divider that can lock onto a Phase-Locked Loop (PLL) output signal in a wide frequency band while achieving lower power consumption and lower phase noise than a differential latch type divider. The ILO is tuned by disabling a Voltage-Controlled Oscillator (VCO) from driving the ILO, adjusting the natural oscillating frequency, making a measurement indicative of the natural oscillating frequency, and determining whether the measurement is within a predetermined range. If the measurement is below the predetermined range, capacitances of resonators within the ILO are decreased, whereas if the measurement is above the predetermined range, capacitances of the resonators are increased.

Abstract: The high-frequency digitally controlled oscillator includes fully digital cells capable of being ported to any CMOS fabrication process. The oscillator has a basic modular architecture comprising a digitally controlled digital ring oscillator (DRO) having a plurality of delay stages, a counter divider and a selection multiplexer. The DRO generates the basic (intrinsic) high frequency range and the counter provides the remaining ranges through division by multiples of two. The multiplexer provides a selection mechanism for the required range of frequencies. Load capacitances to the delay stages are added/removed to control delay via utilization of a unique capacitive cell driven synchronously by two ring oscillators such that the capacitance could be added or removed utilizing the Miller effect. Moreover, multiple capacitive load cells can be added to the same stage.

Abstract: In one general aspect, an apparatus can include a reference oscillator counter circuit configured to produce a reference oscillator count value based on a reference oscillator signal, and a target oscillator counter circuit configured to produce a target oscillator count value based on a target oscillator signal where the target oscillator signal has a frequency targeted for calibration against a frequency of the reference oscillator signal. The apparatus can include a difference circuit configured to calculate a difference between the reference oscillator counter value and the target oscillator counter value, and a summation circuit configured to define a trim code based on only a portion of bit values from the difference.

Abstract: A semiconductor integrated circuit capable of reliably detecting oscillation stop of a vibrator-type oscillation circuit and reliably restarting the oscillation circuit when oscillation stop is detected is provided. The semiconductor integrated circuit includes one or more main oscillation circuits configured to generate a main clock signal by a vibrator, a ring oscillator configured to always operate independently of the main oscillation circuit, a main clock detection circuit configured to monitor the main clock signal on the basis of an output clock signal of the ring oscillator and to determine an operation state of the main oscillation circuit, and an switch circuit configured to switch a combination of elements making up the main oscillation circuit in response to a detection result of the main clock detection circuit.

Abstract: A technique for enhancing the frequency tuning range for monolithic RF source generation using fully-integrated coupled Voltage-Controlled-Oscillator (VCO) arrays that contain an odd number of VCOs. Fully-monolithic SiGe VCO arrays using on-chip inductor and varactor with on-chip bias current sources have been carefully designed and simulated in IBM 7HP 0.18 ?m BiCMOS technology and taped out for fabrication. The SPICE simulated frequency and phase tuning of the 1-D VCO×5 array is dependent on the edge VCOs termination impedance, the tuning voltages, and the VCO coupling strength. The simulated data suggests that the enhanced tuning range and beam steering can be accomplished using coupled-VCO arrays without needing complex and bulky phase shifters. This design technique imposes no apparent phase noise penalty but can provide simulated RF frequency tuning range of ˜40% and also ˜+/?25° beam steering for active antennas applications.

Abstract: An apparatus includes an adjustable oscillator circuit configured to generate an output signal having a frequency that varies responsive to a frequency control signal and a frequency reference generator circuit configured to produce a frequency reference signal. The apparatus further includes a calibration circuit configured to determine a relationship of the output signal to the frequency reference signal and to enable and disable the frequency reference generator circuit based on the determined relationship.

Abstract: A voltage-controlled oscillator (VCO) module including a first VCO unit, a second VCO unit, and a matching circuit is provided. The first VCO unit includes a first terminal and a second terminal and generates a first oscillator signal. The second VCO unit is coupled to the first VCO unit and generates a second oscillator signal. The matching circuit is coupled between the first VCO unit and second VCO unit. The matching circuit includes a plurality of inductor modules respectively coupled between the first terminal of the first VCO unit and the second VCO unit, between the first terminal and the second terminal of the first VCO unit, and between the second terminal of the first VCO unit and the second VCO unit. Furthermore, a method for generating oscillator signals is also provided.

Abstract: Aspects of a method and system for frequency tuning based on characterization of an oscillator are provided. A value of a first control word which controls a variable impedance of an oscillator may be determined. The determined value may be mapped to a corresponding value of a second control word which controls a variable impedance of a tuned circuit. The mapping may be based on a relationship between the variable impedance of the oscillator and the variable impedance of the tuned circuit, such as logical and/or mathematical relationship. The value of the first control word may be determined based on desired frequency of the tuned circuit and/or based on a desired impedance of the variable impedance of the tuned circuit. The tuned circuit may comprise, for example, an oscillator or a filter.

Abstract: A quadrature VCO includes a first oscillator unit and a second oscillator unit. Each of the first and second oscillator unit is composed of a DC bias source, a complementary cross-coupled pair, an LC resonator unit, a frequency-doubling sub-harmonic coupler unit, and a ground terminal. When the LC resonator units of the first and second oscillator units are operated, four signals of different phases can be outputted via the output terminals. In this way, the output phase difference of the two oscillator units can keep 180 degrees and allow the two oscillator units to mutually inject signals to generate quadrature output signals.

Abstract: The present disclosure provides a tunable signal source having a plurality of oscillator cores having a coupling input, a coupling output, and a power output that is common to each of the plurality of oscillator cores. Also included is a plurality of tunable phase shifters wherein corresponding ones of the plurality of tunable phase shifters are communicatively coupled between the coupling input and the coupling output of corresponding ones of the plurality of oscillator cores, thereby forming a loop of alternating ones of the plurality of oscillator cores and alternating ones of the plurality of tunable phase shifters.

Abstract: A method for adjusting an oscillator clock frequency, comprising: providing a first oscillator, applying a first setpoint value to the first oscillator, determining a first oscillator frequency value within a first time frame, providing a second oscillator, applying a second setpoint value to the second oscillator, determining a second oscillator frequency value within a second time frame, determining a new frequency setpoint value from the first and second frequency values, the first and second setpoint values, and a desired frequency value, and applying the new frequency setpoint value to one of the first and second oscillators.

Abstract: The present invention provides an oscillator and a communication system using the oscillator, in particular, an LC oscillator adapted to lessen phase noise deterioration due to harmonic distortions and increase the amplitude of oscillation, thereby having a favorable low phase noise characteristic. The oscillator comprises at least one voltage to current converter consisting of a transistor and a resonator comprising two LC tanks consisting of a pair of conductive elements and inductive elements. A feedback loop is formed such that an output terminal of the voltage to current converter is connected to the resonator and a current input to the resonator is converted to a voltage which is in turn fed back to an input terminal of the voltage to current converter. Inductive elements constituting the two LC tanks constituting the resonator are mutually inductively couple and a coefficient of the mutual induction is about ?0.6.

Abstract: A tunable multiphase ring oscillator includes a plurality of stages connected in series in a ring structure, where each stage generating a stage output from a stage input. Each stage of the tunable multiphase ring oscillator includes a plurality of trans-conductance cells, each generating an output from at least one portion of the stage input. Each stage further includes at least one phase shifting module for imparting at least one phase shift to the at least one portion of the stage input, an oscillator unit for generating the stage output from a combination of the plurality of outputs, and means for varying at least one of the plurality outputs so as to adjust a phase of the stage output.

Abstract: The invention discloses a dual frequency multiplexer by which a first and second coaxial harmonic oscillator type band pass filters are disposed in a box. The box includes a base body, a cover plate and a cover body. The two coaxial harmonic oscillator type hand pass filters are located on the base body and spaced each other by a metal plate; the multiplexer port, first and second ports are positioned on lateral side of the base body. The blocking capacitors are contained in the coaxial chamber of the two coaxial harmonic oscillator type band pass filters. The cover plate is secured on the base body; the first and second direct current circuits are placed on the cover plate; the low pass filters of the first and second direct current circuits are fixed on an edge of a top surface of the coaxial chamber by means of a support member; the cover body and the base body are fastened with each other. The blocking capacitors each are of distributed parameter capacitor.

Abstract: An oscillation device capable of highly accurate temperature compensation of an output frequency is provided. The oscillation device includes: first and second oscillator circuits oscillating first and second quartz-crystal resonators with overtones respectively; a frequency difference detecting part finding a value corresponding to a difference value between values corresponding to differences between f1 and f1r and between f2 and f2r, where f1 and f2 are oscillation frequencies of the first and second oscillator circuits, and f1r and f2r are oscillation frequencies of the first and second oscillator circuits at a reference temperature; and a correction value obtaining part which, based on the value corresponding to the difference value and a relation between the value corresponding to the difference value and a frequency correction value of the oscillation frequency f1, obtains the frequency correction value of f1, wherein the output frequency is corrected based on the found frequency correction value.

Abstract: A quadrature VCO includes a first oscillator unit and a second oscillator unit. Each of the first and second oscillator unit is composed of a DC bias source, a complementary cross-coupled pair, an LC resonator unit, a frequency-doubling sub-harmonic coupler unit, and a ground terminal. When the LC resonator units of the first and second oscillator units are operated, four signals of different phases can be outputted via the output terminals. In this way, the output phase difference of the two oscillator units can keep 180 degrees and allow the two oscillator units to mutually inject signals to generate quadrature output signals.

Abstract: A first oscillating signal may be generated via a first direct digital frequency synthesizer of a communication device. One or more second oscillating signals may be generated via one or more second direct digital frequency synthesizers of the communication device. Signals received via a plurality of antennas may be processed utilizing the first oscillating signal. Signals to be transmitted via the plurality of antennas may be processed utilizing the first oscillating signal and the one or more second oscillating signals. The communication device may comprise a plurality of receive channels, a plurality of transmit channels, and a multiplexer. The first oscillating signal may be coupled, via the multiplexer, to the plurality of receive paths and one of the transmit paths. During time intervals in which the communication device is configured to receive signals via the plurality of antennas, the multiplexer may route the first oscillating signal to the first one or more direct digital frequency synthesizers.

Abstract: The invention provides a dual-mode voltage-controlled oscillator (DMVCO), a frequency synthesizer and a wireless receiving device, and pertains to the technical field of integrated circuit of radio frequency wireless receiver. The DMVCO and the frequency synthesizer can operate in a wideband mode and a quadrature mode. When operating in the quadrature mode, a quadrature signal is provided for a Single Sideband Mixer of the frequency synthesizer by a quadrature coupling of a first voltage-controlled oscillator unit and a second voltage-controlled oscillator unit in the DMVCO in the overlapped frequency band so that the frequency synthesizer can cover a higher output frequency band. Therefore, the tuning range of the DMVCO of the invention is wide, and the frequency synthesizer using the DMVCO is low in power consumption, simple in structure and has good frequency spur performance.

Abstract: Oscillator circuit for radio frequency transceivers. An oscillator circuit includes a first oscillator that generates a signal having a first frequency and a second oscillator that generates a signal having a second frequency. The oscillator circuit includes a mixer that is responsive to the signal having the first frequency and the signal having the second frequency to provide a signal having a third frequency and one or more frequency components. The oscillator circuit includes a filter that is responsive to the signal from the mixer to attenuate the one or more frequency components and provide a signal having a desired frequency. The oscillator circuit includes a correction circuit to correct a drift in at least one of the first frequency and the second frequency by controlling the second frequency, thereby correcting the drift in the third frequency and the desired frequency.

Abstract: A multi-slicing horizontal synchronization signal generating apparatus and method is provided. The apparatus includes a slicer, a numerically controlled oscillator (NCO), a first phase detector, a second phase detector and a calibration circuit. The slicer performs edge detection on a video signal having a first horizontal synchronization, and generates a first detection signal and a second detection signal according to a first voltage level and a second voltage level, respectively. The NCO generates a second horizontal synchronization signal. The first phase detector detects a first phase difference between the first detection signal and the second horizontal synchronization signal, and the second detector detects the second phase difference between the second detection signal and a reference time point. The calibration circuit generates a calibration signal according to the first phase difference and the second phase difference.

Abstract: A voltage control oscillator includes: first and second field effect transistors, a drain of one of which is connected to a gate of the other and a drain of the other of which is connected to a gate of the one; third and fourth field effect transistors, a drain of one of which is connected to a gate of the other and a drain of the other of which is connected to a gate of the one; a first inductor connected between the drain of the first field effect transistor and the drain of the second field effect transistor; a second inductor connected between the drain of the third field effect transistor and the drain of the fourth field effect transistor; a third inductor magnetically coupled to the first inductor; a fourth inductor magnetically coupled to the second inductor; a first capacitor that capacitively couples one end of the third inductor and one end of the fourth inductor; and a second capacitor that capacitively couples the other end of the third inductor and the other end of the fourth inductor.

Abstract: Configurable phase-locked loop circuitry is provided. The phase-locked loop circuitry may include a buffer having a buffer output and a multiplexer having inputs and an output. The phase-locked loop circuitry may include multiple voltage-controlled oscillators. The phase-locked loop circuitry may be configured to switch a desired one of the voltage-controlled oscillators into use. Each voltage-controlled oscillator may be controlled by control signals applied to a control input for that voltage-controlled oscillator. The control input of each voltage-controlled oscillator may be connected to the buffer output. The output of each voltage-controlled oscillator may be connected to a respective one of the multiplexer inputs. Power-down transistors may be used to disable unused voltage-controlled oscillators to conserve power. The power-down transistors and the multiplexer may be controlled by signals from programmable elements.

Abstract: In a dual band capable voltage controlled oscillator VCO circuit comprising two voltage controlled oscillator units VCO1, VCO2, the voltage controlled oscillator units VCO1, VCO2 are synchronized and connected via at least two coupled transmission lines TL1, TL2, the transmission lines (TL1, TL2) are arranged to operate according to one of two modes to enable varying a combined inductance of the synchronized oscillator units VCO1, VCO2 and the oscillation frequency for the voltage controlled oscillator circuit VCO.

Abstract: In one embodiment, a method includes generating, by a LCVCO, a first signal having a first phase based on a resonant frequency of a first LC tank; generating, by a second LCVCO, a second periodic signal having a second phase based on a resonant frequency of a second LC tank; determining a phase offset between the first LC tank and the second LC tank based on the first and second signals; generating a first output signal and a second output signal based on the determined phase offset; and adjusting the phase offset such that the phase offset is substantially equal to a predetermined phase offset. In one embodiment, the adjusting comprises modulating a first impedance of the first LC tank based on the first output signal, and/or modulating a second impedance of the second LC tank based on the second output signal.

Abstract: A wideband frequency generator has two or more oscillators for different frequency bands, disposed on the same die within a flip chip package. Coupling between inductors of the two oscillators is reduced by placing one inductor on the die and the other inductor on the package, separating the inductors by a solder bump diameter. The loosely coupled inductors allow manipulation of the LC tank circuit of one of the oscillators to increase the bandwidth of the other oscillator, and vice versa. Preventing undesirable mode of oscillation in one of the oscillators may be achieved by loading the LC tank circuit of the other oscillator with a large capacitance, such as the entire capacitance of the coarse tuning bank of the other oscillator. Preventing the undesirable mode may also be achieved by decreasing the quality factor of the other oscillator's LC tank and thereby increasing the losses in the tank circuit.

Abstract: Embodiments of the present invention relate to a self injection locked voltage controlled oscillator arrangement, a pair of coupled first and second voltage controlled oscillator devices are arranged on a chip, an amplifier device is arranged on the same of the refection type chip, and an off-chip delay line is arranged with one terminal connected to an output terminal of the coupled first and second voltage controlled oscillator devices, and on terminal adapted to reflect a signal from the output terminal, the amplifier device being arranged to amplify an injection signal from said output terminal and to supply the amplified injection signal to one of said first and second voltage controlled oscillation devices to provide a VCO arrangement that exhibits low phase noise and a small size.

Abstract: An apparatus and a method for compensating for a mismatch in temperature coefficients of two oscillator frequencies to match a desired frequency ratio between the two oscillator frequencies over a temperature range. In one embodiment of a temperature sensor, first and second oscillators of different temperature characteristics are coupled to a differential frequency discriminator (DFD) circuit. The DFD circuit compensates for the different characteristics in order to match a frequency difference between the first and second frequencies over a temperature range.

Abstract: A voltage-controlled oscillator comprises a first oscillator and a second oscillator. The first oscillator may generate a plurality of intermediate clock signals at a plurality of first nodes, multiply connected to a plurality of first ring shape circuits, in response to a control voltage. The plurality of intermediate clock signals may have a different phase from each other and a same phase difference with each other. The second oscillator may generate a plurality of output clock signals at a plurality of second nodes, multiply connected to a plurality of second ring shape circuits, by changing a voltage level of the intermediate clock signals. The plurality of second ring shape circuits may pass the plurality of first nodes.

Abstract: Oscillator circuit for radio frequency transceivers. An oscillator circuit includes a first oscillator that generates a signal having a first frequency and a second oscillator that generates a signal having a second frequency. The oscillator circuit includes a mixer that is responsive to the signal having the first frequency and the signal having the second frequency to provide a signal having a third frequency and one or more frequency components. The oscillator circuit includes a filter that is responsive to the signal from the mixer to attenuate the one or more frequency components and provide a signal having a desired frequency. The oscillator circuit includes a correction circuit to correct a drift in at least one of the first frequency and the second frequency by controlling the second frequency, thereby correcting the drift in the third frequency and the desired frequency.

Abstract: Embodiments of the present invention include a low phase noise oscillator circuit using a current-reuse technique to reduce power consumption and improve phase noise, where the oscillator circuit comprises a first VCO coupled to a second VCO, and the outputs of the first and second VCOs are coupled with passive elements, such as capacitors. The overall power consumption of both the first and second VCOs is about the same as a single VCO. Furthermore, the phase noise is lowered by around 3 dB. Thus, the phase noise performance is improved without increasing the power consumption of the oscillator circuit.