A resonator is supplied with voltage from a constant-voltage source, and the constant-voltage source outputs output voltage adjusted by a voltage adjustment signal to the resonator. The resonator outputs a clock signal having a frequency varied by varying capacitance in accordance with a received control signal and a frequency adjustment signal, and a frequency of the clock signal is varied by voltage output from the constant-voltage source.

A frequency modulator includes a first pair of diodes with two capacity diodes, and a second pair of diodes with two additional capacity diodes. The second pair of diodes is employed in parallel. The frequency modulator also includes a first modulator input for reception of a first modulation signal and a second modulator input for reception of a symmetrical second modulation signal. Both pairs of diodes are coupled to an oscillator unit.

A first capacitor has a capacitance adjustable to a set point value by application of a bias voltage. A second capacitor also has a capacitance adjustable to a set point value by application of a bias voltage. The first and second capacitors are arranged to receive the same bias voltage generated by a control circuit. The control circuit receiving the set point value as an input and generates that bias voltage in response to a quantity representative of a capacitance of the second capacitor.

A reconfigurable, digital phase-locked loop integrated circuit is disclosed which is coupleable to a reference frequency generator. A representative embodiment may include a memory storing a plurality of configuration parameters, at least one configuration parameter of specifying an output frequency; a reconfigurable frequency and delay generator configurable and reconfigurable in response to the configuration parameters to generate an output signal having the output frequency; and a digital controller adapted to access the memory and retrieve the plurality of configuration parameters, and to generate a plurality of control signals to the reconfigurable frequency and delay generator both to generate the output signal having the output frequency in response to the plurality of configuration parameters, and to match a phase of the output signal to an input signal phase.

Method and systems are provided for voltage-controlling and tuning of oscillators. An example system may include a signal source that provides an input signal for generating oscillations and a frequency tuning network for tuning frequency of the oscillations. The frequency tuning network may include one or more input circuits configured for receiving the input signal from the signal source, and a plurality of capacitors. The frequency tuning network may be configured to tune the frequency of the oscillations by adjusting at least one parameter or function applicable to capacitance within the frequency tuning network and/or within other components of the system. The frequency tuning network may be configured to tune the frequency of the oscillations by adjusting amplifying of capacitance. Adjusting amplifying of capacitance in the system may include inhibiting amplifying of at least one capacitor within at least one other component of the system.

Method and systems are provided for voltage-controlling and tuning of oscillators. An oscillator may comprise comprises an oscillator core configured for contributing gain to oscillations generated in the oscillator and a frequency tuning network connected between the oscillator core and a signal source that provides an input signal for creating the oscillations in the oscillator. The frequency tuning network may be configured for tuning frequency of the oscillations, to inhibit amplifying a first capacitance from the oscillator core and to amplify a second capacitance from the frequency tuning network. The frequency of oscillations may be tuned by varying a capacitance, and isolating one or more of noise sources or parasitic capacitances from the tuning network.

A first capacitor has a capacitance adjustable to a set point value by application of a bias voltage. A second capacitor also has a capacitance adjustable to a set point value by application of a bias voltage. The first and second capacitors are arranged to receive the same bias voltage generated by a control circuit. The control circuit receiving the set point value as an input and generates that bias voltage in response to a quantity representative of a capacitance of the second capacitor.

Method and systems are provided for voltage-controlling and tuning of oscillators. An oscillator may comprise comprises an oscillator core configured for contributing gain to oscillations generated in the oscillator and a frequency tuning network connected between the oscillator core and a signal source that provides an input signal for creating the oscillations in the oscillator. The frequency tuning network may be configured for tuning frequency of the oscillations, to inhibit amplifying a first capacitance from the oscillator core and to amplify a second capacitance from the frequency tuning network. The frequency of oscillations may be tuned by varying a capacitance, and isolating one or more of noise sources or parasitic capacitances from the tuning network.

A frequency calibration method for calibrating an output frequency of a voltage-controlled oscillator is provided. The voltage-controlled oscillator includes a first capacitor bank, a second capacitor bank, and a third capacitor bank. The first capacitor bank and the third capacitor bank are initially disabled and the second capacitor bank is initially enabled. The method includes, when the initial output frequency is lower than a reference frequency, adjusting the capacitance of the second capacitor bank until the calibrated output frequency is greater than the reference frequency, and when the initial output frequency is greater than the reference frequency, enabling the first capacitor bank and gradually increasing the capacitance of the first capacitor bank until the calibrated output frequency is lower than the reference frequency.