Abstract: An electronic device has a capacitive arrangement for controlling a frequency characteristic. The capacitive arrangement has varactor banks having a number of parallel coupled varactors and a control input for switching the respective varactors on or off. A main varactor bank has N varactors and a series varactor bank has A varactors, the main varactor bank being connected in series with the series varactor bank. A shunt varactor bank of B varactors may be coupled to a ground reference and connected between the main varactor bank and the series varactor bank. When a varactor is switched in the main varactor bank, it provides an equivalent capacitance step size (or frequency step) smaller than size of a capacitance step when switching a single varactor on or off. According to the number of varactors selected in the shunt varactor, B, this frequency step can be made programmable.

Abstract: An integrated circuit device comprises tuning signal circuitry for generating a tuning signal for calibrating a voltage controlled oscillator (VCO). The tuning signal circuitry is arranged to receive a target voltage signal that is representative of a target voltage across at least one passive element within a resonant tank circuit of a VCO that is being calibrated, generate a VCO simulation signal representative of an average voltage difference across at least one active component of the VCO that is being calibrated, and output a tuning signal based at least partly on the received target voltage signal and the generated VCO simulation signal.

Abstract: An electronic device has a calibration arrangement for controlling a frequency characteristic of a PLL circuit having a phase comparator having an output for generating a phase difference signal, a voltage controlled oscillator and a divider. The divisor of the divider is programmable, and the oscillator is also directly modulated by an oscillator modulation signal. A modulation unit has a modulation input for receiving a modulation signal and generates the oscillator modulation signal and the divisor such that modulation generates a predefined change of the output frequency and a change of the divisor proportional to said predefined change. The calibration arrangement receives the phase difference signal, and has a ripple detector for providing a detector output signal by detecting a ripple on the phase difference signal correlated to edges in the modulation signal. A calibration control unit adjusts the oscillator modulation signal based on the detector output signal such that the ripple is reduced.

Abstract: An integrated circuit device comprises tuning signal circuitry for generating a tuning signal for calibrating a voltage controlled oscillator (VCO). The tuning signal circuitry is arranged to receive a target voltage signal that is representative of a target voltage across at least one passive element within a resonant tank circuit of a VCO that is being calibrated, generate a VCO simulation signal representative of an average voltage difference across at least one active component of the VCO that is being calibrated, and output a tuning signal based at least partly on the received target voltage signal and the generated VCO simulation signal.