Provided herein are apparatus and methods for reducing supply noise conversion to phase noise. In certain configurations, voltage controlled elements such as varactors are used to control a VCO output frequency. A VCO transfer function relating supply voltage noise to a common node of a varactor gives rise to a transfer function of value a representing a push coefficient. An intentional amount of supply noise can be added to a tuning voltage by injecting it at a tuning port of the VCO. By splitting an integration capacitance in a loop filter, an integration capacitance can be divided among a capacitor divider to create a transfer function of value representing a compensating coefficient. The injected noise from the capacitor divider can reduce VCO pushing by canceling the value . When the value is set equal to the value , the VCO pushing can be reduced to within the estimation or measurement accuracy of the value .

Provided herein are apparatus and methods for reducing supply noise conversion to phase noise. In certain configurations, voltage controlled elements such as varactors are used to control a VCO output frequency. A VCO transfer function relating supply voltage noise to a common node of a varactor gives rise to a transfer function of value a representing a push coefficient. An intentional amount of supply noise can be added to a tuning voltage by injecting it at a tuning port of the VCO. By splitting an integration capacitance in a loop filter, an integration capacitance can be divided among a capacitor divider to create a transfer function of value representing a compensating coefficient. The injected noise from the capacitor divider can reduce VCO pushing by canceling the value . When the value is set equal to the value , the VCO pushing can be reduced to within the estimation or measurement accuracy of the value .

An integrated electronic circuit is provided. The integrated electronic circuit includes a transconductance cell formed from transconductance cell devices. The integrated electronic circuit further includes active and passive decoupling circuits. The integrated electronic circuit also includes an oscillator having a tank that is direct current decoupled from the transconductance cell devices using the active and passive decoupling circuits to increase voltage swing and decrease phase noise of the oscillator.

An oscillator includes first, second, and third current sources, a resistor having first and second terminals, first and second capacitors each having first and second terminals, a switch circuit through which each of the current sources is connectable to the first terminal of one of the resistor and the two capacitors to supply current thereto, a comparator, and switch controller configured to generate control signals for the switch circuit and an oscillation output signal for each of multiple periods based on an output signal from the comparator. During one of the periods, the switch circuit is controlled to connect the first current source to the first terminal of the first capacitor, the second current source to the first terminal of the resistor, the first terminal of the resistor to a first input of the comparator, and the first terminal of the first capacitor to a second input of the comparator.

An oscillator includes first, second, and third current sources, a resistor having first and second terminals, first and second capacitors each having first and second terminals, a switch circuit through which each of the current sources is connectable to the first terminal of one of the resistor and the two capacitors to supply current thereto, a comparator, and switch controller configured to generate control signals for the switch circuit and an oscillation output signal for each of multiple periods based on an output signal from the comparator. During one of the periods, the switch circuit is controlled to connect the first current source to the first terminal of the first capacitor, the second current source to the first terminal of the resistor, the first terminal of the resistor to a first input of the comparator, and the first terminal of the first capacitor to a second input of the comparator.

Various aspects of an injection-locked oscillator and method for controlling jitter and/or phase noise are disclosed herein. In accordance with an embodiment, an injection-locked oscillator includes one or more circuits that are configured to receive a pair of complementary phase output signals from one or more gain stages of the injection-locked oscillator. The one or more circuits may be configured to receive one or more switching signals. The received pair of complementary phase output signals are shorted by use of the one or more received switching signals. The shorting reduces the phase difference between an input signal and an output signal of the injection-locked oscillator.

Various aspects of an injection-locked oscillator and method for controlling jitter and/or phase noise are disclosed herein. In accordance with an embodiment, an injection-locked oscillator includes one or more circuits that are configured to receive a pair of complementary phase output signals from one or more gain stages of the injection-locked oscillator. The one or more circuits may be configured to receive one or more switching signals. The received pair of complementary phase output signals are shorted by use of the one or more received switching signals. The shorting reduces the phase difference between an input signal and an output signal of the injection-locked oscillator.

A unit comprising a quartz crystal resonator having an overall length less than 2.1 mm and a base portion including a length less than 0.5 mm and a width less than 0.55 mm, and vibrational arms, mounting arms being connected to the base portion through connecting portions, each vibrational arm having a first vibrational portion including a first width and a first length within a range of 0.32 mm to 0.72 mm and a second vibrational portion including a second width greater than the first width and a second length less than the first length, a groove being formed in at least one of opposite main surfaces of the first vibrational portions of the vibrational arms, a width of the groove being less than 0.07 mm and a distance in the width direction of the groove measured from an outer edge of the groove to an outer edge of the corresponding arm being less than 0.015 mm, a width of the mounting arms being less than 0.45 mm and a width of the connecting portions being less than 0.41 mm, the second width being greater than a spaced-apart distance between the second vibrational portions.

An integrated electronic circuit is provided. The integrated electronic circuit includes a transconductance cell formed from transconductance cell devices. The integrated electronic circuit further includes active and passive decoupling circuits. The integrated electronic circuit also includes an oscillator having a tank that is direct current decoupled from the transconductance cell devices using the active and passive decoupling circuits to increase voltage swing and decrease phase noise of the 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.