703 results about "Voltage-controlled oscillator" patented technology

The invention discloses an ultra-low phase noise harmonic wave type four-core voltage-controlled oscillator. The ultra-low phase noise harmonic wave type four-core voltage-controlled oscillator is composed of a transformer T1, a transformer T2, a transformer T3, a transformer T4, a head oscillator HR1, a head oscillator HR2, a head oscillator HR3, a head oscillator HR4, a resistor R1, a resistor R2, a resistor R3, a resistor R4 and a plurality of decoupling capacitors Cecap. According to the voltage-controlled oscillator, noise is prevented from being converted into phase noise by means of second and third harmonic impedance broadening, inductance loss reduction, reduction of the sensitive time of the resonant cavity to the noise and the like, the phase noise generated by the voltage-controlled oscillator can be effectively reduced, and excellent noise performance is obtained.

The invention discloses a low-phase noise ring voltage-controlled oscillator based on multiphase injection locking, relates to the technical field of integrated circuits, and is used for solving the technical problems that an existing injection locking oscillator limits the frequency tuning range and cannot effectively suppress noise. The invention discloses a low-phase noise ring voltage-controlled oscillator based on multiphase injection locking. The low-phase noise ring voltage-controlled oscillator comprises a first ring oscillator unit and a second ring oscillator unit, the n first ring oscillator units are connected in series to form a chain structure; the second ring oscillator unit is provided with a cross coupling inverter complementary injection unit and a tail current source injection unit; a first output end of the chain structure is connected with a second input end of the second ring oscillator unit, and a second output end of the chain structure is connected with a first input end of the second ring oscillator unit; a first signal is injected into a cross-coupling inverter complementary injection unit and a tail current source injection unit, and a second ring oscillator unit receives a second signal output by a chain structure and then outputs a third signal.

The invention discloses a reference-clock-free clock and data recovery circuit, a use method and an integrated circuit. The circuit comprises a first circuit and a second circuit, the first circuit comprises a voltage-controlled oscillator, the second circuit comprises a comparison module and a frequency capture module, and the comparison module is used for comparing a first clock signal with a high-speed serial data signal, generating a first signal and outputting the first signal to the frequency capture module. The frequency capture module outputs a first control signal, the first control signal is used for adjusting the first oscillation frequency so as to enable the frequency deviation between the first oscillation frequency and the second oscillation frequency to be smaller than a first deviation threshold value, and the second circuit generates a second clock signal and outputs the second clock signal to the first circuit; the first circuit adjusts the voltage-controlled oscillator using a second clock signal such that the frequency offset is less than a second offset threshold. According to the invention, the CDR and PLL functions are fused and an external reference clock is replaced by the CDR recovery clock, so that a clock and data recovery system without an external clock is realized.

A low-phase noise class-D voltage-controlled oscillator based on a broadband harmonic shaping technology comprises a head resonance unit, an LC resonance unit composed of a first inductance unit, a second inductance unit and a first capacitance unit, a negative resistance unit, a variable capacitance unit, an array capacitance unit and an output unit. The output end of the head resonance unit is connected with one end of the first inductance unit, the other end of the first inductance unit is connected with one end of the negative resistance unit, the other end of the negative resistance unit is connected with the first capacitor unit, the first capacitor unit is connected with the variable capacitor unit, and the variable capacitor unit is connected with one end of the array capacitor unit. The other end of the array capacitor unit is connected with one end of the second inductor unit, the other end of the second inductor unit is grounded, two input ends of the output unit are connected with the variable capacitor unit, and two output ends of the output unit serve as output ports of the voltage-controlled oscillator.

The invention relates to a class-C voltage-controlled oscillator with negative-pressure substrate bias and a use method thereof. Aiming at the problem that a traditional C-type voltage-controlled oscillator is difficult to start, the C-type voltage-controlled oscillator provided by the scheme adopts different circuits to simultaneously control the grid voltage and the substrate voltage of the cross-coupled pair transistors, so that the transistors are effectively prevented from entering a linear region, and the C-type voltage-controlled oscillator is quickly started and stably works in a C-type oscillation mode. The circuit structure of the scheme comprises an NMOS (N-channel Metal Oxide Semiconductor) cross coupling circuit, a PMOS (P-channel Metal Oxide Semiconductor) cross coupling circuit, an LC resonant cavity circuit, an amplitude detection circuit, a Schmidt signal processing circuit and a negative voltage charge pump circuit. Wherein the Schmidt signal processing circuit and the negative voltage charge pump circuit rapidly process an initial oscillation signal and provide negative voltage required by the system, and a substrate of the NMOS cross coupling tube is biased. According to the scheme, the design structure is simple, the tuning range is wide, and a new thought is provided for research and design of quick start of the C-type voltage-controlled oscillator.

The invention discloses an anti-radiation hardening digital controlled oscillator, a clock data recovery circuit and equipment, and the digital controlled oscillator is characterized in that an anti-radiation hardening circuit unit is connected between a digital-to-analog converter (DAC) and a voltage-controlled oscillator (VCO), and comprises a voltage copying unit and a multiplexer; the voltage copying unit is used for copying a control voltage signal output by the digital-to-analog converter DAC, generating a copying voltage signal, sending the copying voltage signal to the multiplexer, and switching the output of the multiplexer from the control voltage signal to the copying voltage signal when the digital-to-analog converter DAC is subjected to single-particle bombardment. The DCO type clock data recovery circuit aims at solving the problem that a traditional DCO type clock data recovery circuit is prone to being affected by single particles when running in a radiation environment, single particle function interruption is generated, and consequently a space task fails, and the radiation hardening capacity of the DCO type clock data recovery circuit running in the radiation environment is improved.

The invention discloses a data converter based on a voltage-controlled oscillator and an implementation method of the data converter. The data converter based on the voltage-controlled oscillator comprises a sampling circuit, a multi-bit successive approximation type data converter and a multi-bit multi-order Delta-Sigma data converter. An incremental scaling type data converter based on a voltage-controlled oscillator is improved, a feed-forward compensation method suitable for the voltage-controlled oscillator is designed, the characteristics of a Delta-Sigma data converter clock are fully utilized, a feed-forward phase is firstly added into a total differential phase of the voltage-controlled oscillator and then subtracted after quantization is finished, and therefore feed-forward compensation of a phase domain is equivalently achieved. A new time sequence is not introduced, so that the implementation cost is low; the voltage-controlled oscillator is completely isolated from sensitive nodes in the circuit, so that kickback noise is avoided; according to the invention, the high-energy-efficiency data converter based on the voltage-controlled oscillator can be constructed more simply, and can be widely applied to the fields of Internet of Things, smart medical treatment and the like.

The invention discloses a fast-locking low-jitter sub-sampling phase-locked loop structure. The sub-sampling phase-locked loop comprises a sub-sampling Bang-Bang phase discrimination circuit, a self-adaptive variable step size digital filter circuit, a delta sigma digital-to-analog conversion circuit and an oscillator circuit. The sub-sampling Bang-Bang phase discrimination circuit generates a phase discrimination output digital control signal according to an input reference signal and a feedback oscillator signal phase error, the adaptive variable step size digital filter circuit adaptively adjusts a filtering gain according to the phase discrimination output digital control signal, and the output of the filter circuit realizes digital-analog conversion after oversampling modulation. And the output analog signal controls the voltage-controlled oscillator to realize rapid low-jitter phase locking of the output and the reference signal.

Embodiments herein relate to an apparatus and method for calibrating a notch filter which filters a power supply signal for a voltage-controlled oscillator (VCO). In one aspect, a control circuit performs a number of calibration cycles for the filter to determine a value of a calibration code for the filter which minimizes a change in a frequency of the output signal of the VCO due to a change in the voltage of the power supply signal. After each calibration cycle, the calibration code is adjusted based on whether the frequency of the output signal increase or decreases. The calibration cycles can therefore converge on an optimal calibration code which minimizes the change in frequency due to the change in voltage. This minimizes a sensitivity of the VCO to noise in the power supply signal.

The invention discloses a processor-free high-signal-to-noise-ratio backscattering label in the field of backscattering label communication, which comprises a crystal oscillator unit, a pulse width modulation unit, an isolation unit, an on-off unit, an oscillation control unit, a radio frequency switch and a radio frequency energy collection module, the radio frequency energy collection module is used for converting a carrier signal transmitted by the transmitter into a direct current signal and stabilizing the voltage, and the radio frequency energy collection module is also used for supplying power to the crystal oscillator unit, the pulse width modulation unit, the oscillation control unit and the radio frequency switch; the invention also provides a backscattering method. The beneficial effects of the invention are that through the pulse width modulation unit and the voltage-controlled oscillator, a backscattering signal is converted from an existing amplitude modulation signal to a frequency modulation signal, the stability and the signal-to-noise ratio of the backscattering signal are greatly improved, and the power consumption is lower.

A clock generation circuit has a voltage-controlled oscillator that includes a first transistor pair coupled in series between a power rail and ground, a replica transistor pair coupled in series between a reference node and ground, a current source having an output coupled to the reference node. The current source is coupled to a control signal that determines amplitude of current flowing through the replica transistor pair. A voltage regulator has an input coupled to the reference node and an output coupled to the power rail. The voltage regulator is configured to maintain the power rail at a voltage level defined by the voltage level of the reference node. Each transistor in the replica transistor pair is collocated on an integrated circuit with and has a same type as a corresponding transistor in the first transistor pair.

The invention discloses a low-power-consumption radiation-resistant quadrature voltage-controlled oscillator based on an SOI (Silicon On Insulator) process, relates to the technical field of quadrature voltage-controlled oscillators, and is used for solving the technical problems that an existing quadrature voltage-controlled oscillator is low in radiation resistance in a harsh radiation environment and does not have the characteristic of low power consumption. The invention discloses a low-power-consumption anti-radiation quadrature voltage-controlled oscillator based on an SOI process. The low-power-consumption anti-radiation quadrature voltage-controlled oscillator comprises a first voltage-controlled oscillator, a second voltage-controlled oscillator, a first tail filter and a second tail filter, the first voltage-controlled oscillator and the second voltage-controlled oscillator respectively form an LC resonant cavity with a parasitic capacitor of an inductor and a varactor through the inductor; the first tail filter is connected with the first voltage-controlled oscillator, and the second tail filter is connected with the second voltage-controlled oscillator; two inductors of the first tail filter and the second tail filter are coupled; lC resonant cavities of the first voltage-controlled oscillator and the second voltage-controlled oscillator output oscillation waveforms, and negative impedance is formed through configured transistor pairs, so that the waveforms are output constantly.

The invention relates to the field of integrated circuit design, and particularly discloses a high power supply rejection ratio and low swing driving frequency-locked loop circuit and a control method thereof, a low dropout regulator is adopted to provide independent power supply lower than a main power supply voltage for a voltage-controlled oscillator, and double optimization effects are achieved. The clean power supply provided by the low dropout linear regulator effectively isolates the interference of the main power supply noise to the voltage-controlled oscillator, so that the power supply noise suppression capability of the circuit is remarkably enhanced, and the jitter of an output clock signal is greatly reduced; and on the other hand, the working voltage of the voltage-controlled oscillator is allowed and dynamically regulated and controlled to be optimized in a low range meeting the performance according to the real-time load of the voltage-controlled oscillator, so that on-demand power supply is realized, the dynamic power consumption of the voltage-controlled oscillator is reduced to the maximum extent while the output quality is not reduced, and the energy efficiency of the whole circuit under different load conditions is improved.

The utility model discloses a vector signal comprehensive test module, which consists of an internal reference clock and a VCO (Voltage Controlled Oscillator), and the reference clock has an internal and external switching function. The VCO adopts a multi-output phase adjustable device and provides local oscillation signals for the two RFICs and the six frequency conversion circuits respectively. The two RFICs are connected in parallel, and an external coherent local oscillator is provided by the VOC, so that the coherence of the two RFICs is realized. The microwave frequency conversion circuit realizes the frequency expansion function of the RFIC, expands two-path emission frequency and four-path reception frequency from tens of MHz to 9KHz, has four radio frequency test functions of vector signal generation, vector signal analysis, vector network analysis and vector transceiver, and realizes the multifunctional and multi-scene application capability of the comprehensive test instrument.

An integrated photonics millimeter wave (MMW) radar communication system based on analog phase modulation scheme includes an integrated photonics MMW radar communication signal transmitter, a radar receiver, and a communication receiver. The transmitter includes a radar communication signal analog phase modulation module, an optical frequency comb (OFC) module, an electro-optic modulator (EOM), an optical shaping filter, an optical power divider, a photoelectric detector, an electric power amplifier, and a transmitting antenna that are cascaded sequentially. The radar receiver includes a radar receiving antenna, an electric low-noise amplifier (LNA), an optical phase modulator, an optical bandpass filter (BPF), a low-speed photoelectric detector, an electric low-pass filter, and a low-speed oscilloscope that are cascaded sequentially. In the communication receiver, a communication receiving antenna is sequentially cascaded with an electric LNA, a frequency mixer, and an oscilloscope, and a voltage-controlled oscillator is cascaded with a frequency multiplier and then connected to the frequency mixer.

The invention discloses a magnetic tuning F-type voltage-controlled oscillator based on multi-coil coupling, and the oscillator comprises an F-type oscillation loop which is used for generating an oscillation signal with a required frequency, and carrying out the harmonic adjustment of a frequency spectrum of the oscillation signal; the magnetic tuning transformer is used for adjusting the voltage-current relationship of the oscillation signal in the F-type oscillation loop, changing the equivalent inductance value in the F-type oscillation loop and further adjusting the oscillation frequency; the common-mode resonant capacitor is used for determining common-mode capacitance in the F-type oscillation loop and further reducing the phase noise at the second harmonic through common-mode resonance; the F-class voltage-controlled oscillator is adopted to enhance harmonic waves to achieve frequency tripling to generate millimeter wave oscillation signals, a magnetic tuning mode is adopted to replace a varactor with a low quality factor to control and change resonant frequency, and compared with a traditional LC voltage-controlled oscillator, the voltage-controlled oscillator can obtain lower phase noise and a higher quality factor, and the performance of the voltage-controlled oscillator is improved. And an additional frequency multiplier is omitted for the generation of the millimeter wave oscillation signal.

The embodiment of the invention provides a voltage-controlled oscillator, an oscillator circuit, a chip and electronic equipment, relates to the technical field of communication or radar detection, and can improve the linearity of the voltage-controlled oscillator. The voltage-controlled oscillator comprises a voltage-controlled oscillator resonant cavity, an even harmonic generator circuit and a self-mixing frequency tripler circuit. The voltage-controlled oscillator resonant cavity comprises a voltage transformation diode array and a first-stage mode switching capacitor. The even harmonic generator circuit comprises a group of cross coupling tubes, one end of each cross coupling tube is electrically connected to the two differential ends of the voltage-controlled oscillator, and the even harmonic generator circuit serves as an even harmonic generator and is electrically connected to the self-mixing frequency tripler circuit. The self-mixing frequency tripler circuit comprises a differential unit and a resonant cavity, and one end of the self-mixing frequency tripler circuit is electrically connected to the even harmonic generator circuit. The low-frequency voltage-controlled oscillator and the self-mixing frequency tripler circuit achieve current multiplexing, the even harmonic generator circuit serves as a negative resistor of the oscillator and also serves as an even harmonic generator of the self-mixing frequency tripler, and the linearity of the millimeter wave frequency source is improved.

The invention discloses a lunar exploration cubesat measurement and control responder system and a transmitting signal coherent carrier generation method thereof, and the system comprises a frequency mixer, a receiving local oscillator phase-locked loop, an intermediate frequency sampling analog-to-digital converter, a voltage-controlled oscillator, a digital-to-analog converter, a transmitting local oscillator phase-locked loop and a carrier tracking loop. Wherein the frequency mixer generates an intermediate-frequency signal according to radio frequency input and a local oscillation signal, the intermediate-frequency signal is output to the intermediate-frequency sampling analog-to-digital converter after band-pass filtering, and the intermediate-frequency sampling analog-to-digital converter outputs the intermediate-frequency signal to the carrier tracking loop after the intermediate-frequency signal is subjected to down-conversion processing of an X-band radio frequency signal; the carrier tracking loop outputs a digital signal to the digital-to-analog converter to generate an analog voltage for controlling the voltage-controlled oscillator; the voltage-controlled oscillator controls the output frequency through the voltage of the digital-to-analog converter; receiving a reference signal output by the local oscillator phase-locked loop according to the voltage-controlled crystal oscillator, performing phase-locked frequency multiplication processing and generating a local oscillator signal; and the transmitting local oscillator phase-locked loop performs phase-locked frequency multiplication processing on the reference signal. According to the invention, in an analog-digital combination mode, a digital frequency-locked phase-locked loop is used for controlling the output voltage of a DAC to control the frequency of a reference VCXO, so that carrier tracking of a radio frequency-intermediate frequency-digital large loop closed loop is completed; downlink coherent carriers can be directly obtained by PLL (Phase Locked Loop), and the requirement of downlink / uplink forwarding ratio 880 / 749 is strictly met.

The invention relates to a CMOS voltage-controlled oscillator applied to an anti-interference unmanned aerial vehicle millimeter wave radar, which belongs to the field of millimeter wave radar design and comprises a resonance circuit, a negative resistance active circuit and two switching circuits with the same structure. The resonant circuit comprises a switched capacitor, a blocking capacitor, a resonant capacitor, a grounding resistor, a tuning resistor and a resonant inductor; the negative resistance active circuit comprises a cross coupling pair MOS tube and a current source. Each switch circuit comprises a switch MOS tube, a grounding resistor and a switch coupling inductor. The dual-phase transformer structure is used, the resonant inductor and the switch coupling inductor are mutually inducted, and therefore the inductance value of the resonant inductor is changed, and frequency band switching is achieved; vCO bandwidth tuning is realized through a combination mode of switch-on and switch-off of a switch capacitor and switch-on and switch-off of a switch coupling inductor; the CMOS technology is adopted for design, and miniaturization and integration of the VCO are achieved. While the performance and layout area of the voltage-controlled oscillator are ensured, the full-band broadband tuning range is realized, thereby improving the detectability and resolution of the millimeter wave radar, enabling the unmanned aerial vehicle to realize frequency hopping communication and spread spectrum communication, and effectively improving the anti-interference capability and safety of the unmanned aerial vehicle.

The invention relates to the technical field of single-phase phase-locked loops, and discloses an improved single-phase phase-locked loop based on a generalized second-order integral and a wave trap, which comprises a phase discriminator, the wave trap, a loop filter and a voltage-controlled oscillator which are electrically connected in series in sequence, the input end of the phase discriminator is connected with a power grid voltage sampling signal, and the phase discriminator processes the power grid voltage sampling signal to obtain an error voltage signal; the phase discriminator inputs the error voltage signal into a wave trap for processing to obtain a voltage signal; the wave trap inputs the voltage signal into a loop filter for processing to obtain a control voltage signal; the loop filter inputs the control voltage signal into the voltage-controlled oscillator to obtain a phase-locked loop output signal; and the voltage-controlled oscillator inputs the phase-locked loop output signal into the phase discriminator. The improved phase-locked loop provided by the invention can effectively solve the problem of large phase locking error under low sampling frequency, improves the performance and stability of the system, and avoids the problems of large error and insufficient precision of the existing phase-locked loop.

The invention discloses a voltage-controlled oscillator with a wide frequency regulation range, relates to the technical field of radio frequency, and aims to solve the problems of narrow and discontinuous output frequency tuning range of an oscillator in the prior art. The voltage-controlled oscillator comprises a passive topology module, an active negative resistance module, a frequency regulation module and a mode switching module, the passive topology module comprises a plurality of mutually coupled inductors; the plurality of inductors are coupled together and provide a required impedance peak; the plurality of inductors comprise a splayed inductance coil, a first annular inductance coil and a second annular inductance coil; the inverted V-shaped inductance coil comprises a first inductance coil, a second inductance coil and a public inductance coil; the frequency adjusting module is used for adjusting the corresponding frequency of the impedance peak; the active negative resistance module is used for providing signal gain for the passive topology module to meet oscillation conditions, and the mode switching module is used for switching working modes of the oscillator. The oscillator has four continuous working frequency bands, and the tuning range of the output frequency is wider.

The invention discloses a frequency stabilized laser based on a double-fiber interferometer. The frequency stabilized laser comprises a narrow linewidth laser, an acousto-optic frequency shifter, a 1 * 2 fiber splitter I, the double-fiber interferometer, a voltage-controlled oscillator and a control module, the output end of the narrow linewidth laser is connected with the input end of the acousto-optic frequency shifter, and the two input ends are connected with the second output end and the third output end of the control module respectively. The driving input end of the acousto-optic frequency shifter is connected with the output end of the voltage-controlled oscillator, and the output end of the acousto-optic frequency shifter is connected with the input end of the 1 * 2 optical fiber splitter I; one output end of the 1 * 2 optical fiber splitter I outputs a frequency-stabilized laser signal, and the other output end of the 1 * 2 optical fiber splitter I is connected with the input end of the double-optical-fiber interferometer; the output end of the double-fiber interferometer is connected with the input end of the control module; the first output end of the control module is connected with the voltage-controlled oscillator, and the second and third output ends are connected with the narrow linewidth laser. According to the invention, laser signal output with high precision and high frequency stability is realized, and the frequency stability of the laser is three to four orders of magnitude higher than that of a narrow linewidth laser.

A 4 frequency-shift keying (4FSK) transceiver is provided. The 4FSK transceiver includes both a 4FSK transmitter and a 4FSK receiver. The 4FSK transmitter includes a voltage-controlled oscillator (VCO) and two data links coupled to the VCO for delivering two parallel streams of input data bits to the VCO. For each pair of parallel input data bits received from the two data links, the VCO outputs a modulated signal having one of four operating frequencies via 4FSK modulation. Separately, the 4FSK receiver includes a power divider, for dividing the multi-frequency modulated signal into two paths of two binary bit streams, and a pair of low-noise amplifiers (LNAs) separately coupled to the two paths and configured as a pair of band-pass filters for filtering two different subsets of the four operating frequencies from the two binary bit streams into two filtered binary bit streams.

The invention provides a clock taming and maintaining method and system and electronic equipment, and the method comprises the steps: controlling a voltage control oscillator to generate at least one reference clock through a digital-to-analog converter, and generating each target clock and a local clock according to the demands of the reference clock and each target clock; acquiring a reference signal for clock taming, and performing clock taming on each target clock based on the reference signal and the local clock to obtain a taming result; and acquiring a control value of the digital-to-analog converter and a current temperature value of the voltage-controlled oscillator, calculating a clock taming fitting curve based on the control value and the current temperature value, and performing clock holding based on the clock taming fitting curve. Therefore, the clock taming and maintaining cost can be reduced, the clock maintaining algorithm is simplified, and the clock taming efficiency is improved.

The invention relates to the technical field of radio frequency integrated circuits, and discloses a low-noise voltage-controlled oscillator circuit which comprises a source electrode following low-noise bias circuit with digital calibration, a source electrode following low-noise bias circuit with digital calibration, a source electrode following low-noise bias circuit with digital calibration and a source electrode following low-noise bias circuit with digital calibration, the cross-coupled amplifier array is composed of a plurality of units, and the source electrode of the cross-coupled amplifier array suppresses low-frequency noise through a resistance-capacitance feedback network and receives a digital amplitude calibration signal so as to dynamically adjust the number of working units and stabilize the output amplitude; the amplitude self-calibration loop consists of digital logic and a peak detector; the switched capacitor unit array is provided with stable direct-current bias; and a wide linear variable capacitor array driven by the stepped bias voltage. Through deep fusion of digital and analog technologies, the phase noise is remarkably reduced, the linear tuning range is widened, the amplitude stability is ensured, the power consumption is reduced, and the method is particularly suitable for a high-performance radio frequency communication chip of the Internet of Things.

The invention discloses a method, a system, a medium and equipment for frequency calibration based on jump search. The method comprises the following steps: acquiring the output clock frequency of a voltage control oscillator; performing frequency detection on the clock frequency, judging whether the current frequency is greater than the target frequency, less than the target frequency or within the target frequency range, and outputting a corresponding indication signal; according to the indication signal output by the frequency detection module, the step length of the calculation logic is adjusted, and the calibration result is fed back to the voltage control oscillator, and the problem that the calibration time of the VCO in large-range frequency calibration is too long is solved.

The invention discloses a phase quick locking circuit for recovering a phase-locked loop from a transition mode, which belongs to the field of integrated circuits and comprises a phase frequency detector-charge pump, a voltage-controlled oscillator, a transition circuit, a feedback frequency eliminator, a switch, a first phase inverter, a second phase inverter, a first AND gate, a second AND gate, a NOR gate, a first trigger and a second trigger. According to the invention, when the input reference signal CLKREF is abnormally disconnected, the standby transition circuit can be used to maintain the voltage-controlled oscillator to work at a stable frequency, and when the input reference signal CLKREF recovers from an abnormally disconnected state, the feedback frequency eliminator is continuously reset to realize synchronization of the output feedback clock DIVIDEROUT and the input reference signal CLKREF. And the maximum phase difference between the output feedback clock DIVIDEROUT and the input reference signal CLKREF when the input reference signal CLKREF recovers from the abnormal off state is greatly reduced, so that the voltage-controlled oscillator can be continuously kept at a stable frequency to maintain the normal work of the system in the process that the input reference signal is abnormal and recovered.

According to one embodiment, an electronic device may be provided, the electronic device comprising an RF circuit and a communication processor operatively connected to the RF circuit, wherein the RF circuit comprises at least one reception circuit, at least one transmission circuit, a first VCO, a second VCO, and a signal detection block electrically connected to the first VCO, and the communication processor is configured to control the RF circuit to change the operating frequency of the second VCO on the basis of determining whether a signal output from the first VCO is an abnormal signal. Various other embodiments may be possible.

The invention discloses a four-core F23 type millimeter wave voltage-controlled oscillator based on an intra-core common mode technology. The voltage-controlled oscillator comprises a three-coil coupling four-core class-F inductor and four voltage-controlled oscillator cores. The three-coil coupling quad-core class-F inductor comprises eight differential ports, four ports are connected with a grid electrode of a core negative resistance tube of the voltage-controlled oscillator, and the other four ports are connected with a drain electrode of the core negative resistance tube of the voltage-controlled oscillator. The negative resistance tubes of the four voltage-controlled oscillator cores are formed by NMOS tubes and PMOS tubes in an alternating mode. The voltage-controlled oscillator is in an F-type working state for differential mode current so as to improve phase noise; noise filtering is performed on the common-mode current through an intra-core natural common-mode path. According to the invention, millimeter wave frequency output with low phase noise can be realized in a compact layout.

The invention discloses a low-power-consumption phase-locked loop circuit with an automatic frequency calibration function. Comprising a voltage-controlled oscillator, an automatic frequency calibration module, a programmable frequency divider, a phase frequency detector, a plurality of charge pump arrays and a switch filter, wherein the automatic frequency calibration module and the programmable frequency divider are in signal connection with the voltage-controlled oscillator; the phase frequency detector is in signal connection with the programmable frequency divider; the charge pump arrays are in signal connection with the phase frequency detector; the switch filter is in signal connection with the voltage-controlled oscillator; the voltage-controlled oscillator comprises a plurality of delay units, and the voltage-controlled oscillator is an annular oscillator formed by cascading a plurality of delay unit rings. The delay unit is a cross-coupled structure based on an inverter and comprises a plurality of transistors, and the plurality of transistors comprise a plurality of PMOS (P-channel Metal Oxide Semiconductor) transistors and a plurality of NMOS (N-channel Metal Oxide Semiconductor) transistors. According to the invention, under the low power supply voltage, four-phase intermediate frequency signals are output with extremely low power consumption, and the application requirements of rapid locking and low noise are met.