Patent classifications
H03B1/04
LOW NOISE CRYSTAL OSCILLATOR
A crystal oscillator having a voltage regulator configured to receive a first power supply voltage and output a second power supply voltage; a source follower configured to receive the second power supply voltage and output a third power supply voltage in accordance with a control voltage; a first inverter operating under the third power supply voltage and configured to receive a first oscillatory signal from a first node and output a second oscillatory signal at a second node; a second inverter operating under the third power supply voltage and configured to output a third oscillatory signal; a crystal placed across the first node and a second node; a first shunt capacitor configured to shunt the first node to ground; a second shunt capacitor configured to shunt the second node to ground; and a clocked lowpass filter configured to output the control voltage in accordance with the pulsed signal.
Method and device for outputting frequency multiplication signal having high harmonic suppression, and storage medium
A method and device for outputting frequency multiplication signal having high harmonic suppression, and a storage medium. The method includes: obtaining initial signal; inputting the initial signal into target circuit, where the target circuit includes parallel circuit, first circuit of the parallel circuit is provided with frequency multiplier, second circuit of the parallel circuit is provided with phase adjustment module, the first circuit is connected to input end and output ends of the target circuit, the second circuit is disconnected from the input end and the output end, the phase adjustment module is configured to adjust a phase of the second circuit to a target phase, and phase difference between the target phase and a first phase of the first circuit is greater than 90 degrees; taking a target signal output from the target circuit as frequency multiplication signal of the initial signal.
Low noise crystal oscillator
A crystal oscillator having a voltage regulator configured to receive a first power supply voltage and output a second power supply voltage; a source follower configured to receive the second power supply voltage and output a third power supply voltage in accordance with a control voltage; a first inverter operating under the third power supply voltage and configured to receive a first oscillatory signal from a first node and output a second oscillatory signal at a second node; a second inverter operating under the third power supply voltage and configured to output a third oscillatory signal; a crystal placed across the first node and a second node; a first shunt capacitor configured to shunt the first node to ground; a second shunt capacitor configured to shunt the second node to ground; and a clocked lowpass filter configured to output the control voltage in accordance with the pulsed signal.
Low noise crystal oscillator
A crystal oscillator having a voltage regulator configured to receive a first power supply voltage and output a second power supply voltage; a source follower configured to receive the second power supply voltage and output a third power supply voltage in accordance with a control voltage; a first inverter operating under the third power supply voltage and configured to receive a first oscillatory signal from a first node and output a second oscillatory signal at a second node; a second inverter operating under the third power supply voltage and configured to output a third oscillatory signal; a crystal placed across the first node and a second node; a first shunt capacitor configured to shunt the first node to ground; a second shunt capacitor configured to shunt the second node to ground; and a clocked lowpass filter configured to output the control voltage in accordance with the pulsed signal.
Phase noise reduction for voltage-controlled oscillator using harmonic filter
A system includes a voltage-controlled oscillator (VCO), a first second-order harmonic filter coupled to the VCO, wherein the first second-order harmonic filter includes a first tunable capacitor, and a second second-order harmonic filter coupled to the VCO, wherein the second second-order harmonic filter includes a second tunable capacitor. The system also includes a measurement circuit coupled to the VCO, wherein the measurement circuit is configured to measure a voltage swing of the VCO. The system also includes a control circuit coupled to the measurement circuit, the first tunable capacitor, and the second tunable capacitor.
Phase noise reduction for voltage-controlled oscillator using harmonic filter
A system includes a voltage-controlled oscillator (VCO), a first second-order harmonic filter coupled to the VCO, wherein the first second-order harmonic filter includes a first tunable capacitor, and a second second-order harmonic filter coupled to the VCO, wherein the second second-order harmonic filter includes a second tunable capacitor. The system also includes a measurement circuit coupled to the VCO, wherein the measurement circuit is configured to measure a voltage swing of the VCO. The system also includes a control circuit coupled to the measurement circuit, the first tunable capacitor, and the second tunable capacitor.
PHASE NOISE REDUCTION FOR VOLTAGE-CONTROLLED OSCILLATOR USING HARMONIC FILTER
A system includes a voltage-controlled oscillator (VCO), a first second-order harmonic filter coupled to the VCO, wherein the first second-order harmonic filter includes a first tunable capacitor, and a second second-order harmonic filter coupled to the VCO, wherein the second second-order harmonic filter includes a second tunable capacitor. The system also includes a measurement circuit coupled to the VCO, wherein the measurement circuit is configured to measure a voltage swing of the VCO. The system also includes a control circuit coupled to the measurement circuit, the first tunable capacitor, and the second tunable capacitor.
PHASE NOISE REDUCTION FOR VOLTAGE-CONTROLLED OSCILLATOR USING HARMONIC FILTER
A system includes a voltage-controlled oscillator (VCO), a first second-order harmonic filter coupled to the VCO, wherein the first second-order harmonic filter includes a first tunable capacitor, and a second second-order harmonic filter coupled to the VCO, wherein the second second-order harmonic filter includes a second tunable capacitor. The system also includes a measurement circuit coupled to the VCO, wherein the measurement circuit is configured to measure a voltage swing of the VCO. The system also includes a control circuit coupled to the measurement circuit, the first tunable capacitor, and the second tunable capacitor.
LOCAL OSCILLATOR AMPLIFICATION WITH REDUCED HARMONIC GENERATION
Techniques for reducing harmonics of a local oscillator (LO) signal. A methodology implementing the techniques according to an embodiment includes splitting an LO signal into first and second LO signals using a passive splitting circuit. The method also includes generating one of either a first enable signal or a second enable signal based on the LO signal frequency. The method further includes amplifying and filtering the first LO signal to generate a first band LO signal, in response to the first enable signal, and amplifying and filtering the second LO signal to generate a second band LO signal, in response to the second enable signal. The method further includes combining, using a passive Wilkinson combiner, output paths of the first band processing circuit and the second band processing circuit to provide either the first band LO signal or the second band LO signal as a reduced harmonic LO signal.
LOCAL OSCILLATOR AMPLIFICATION WITH REDUCED HARMONIC GENERATION
Techniques for reducing harmonics of a local oscillator (LO) signal. A methodology implementing the techniques according to an embodiment includes splitting an LO signal into first and second LO signals using a passive splitting circuit. The method also includes generating one of either a first enable signal or a second enable signal based on the LO signal frequency. The method further includes amplifying and filtering the first LO signal to generate a first band LO signal, in response to the first enable signal, and amplifying and filtering the second LO signal to generate a second band LO signal, in response to the second enable signal. The method further includes combining, using a passive Wilkinson combiner, output paths of the first band processing circuit and the second band processing circuit to provide either the first band LO signal or the second band LO signal as a reduced harmonic LO signal.