A tunable inductor arrangeable on a chip or substrate comprises a first winding part connected at one end to a first input of the tunable inductor arrangement, a second winding part connected at one end to the other end of the first winding part, a third winding part connected at one end to a second input of the tunable inductor arrangement, a fourth winding part connected at one end to the other end of the third winding part, and a switch arrangement arranged. The switch arrangement tunes the tunable inductor by selectively connecting the first and fourth winding parts in parallel and the second and third winding parts in parallel, with the parallel couplings in series between the first and second inputs, or connecting the first, second, fourth and third winding parts in series between the first and second inputs. Corresponding transceivers, communication devices, methods and computer programs are disclosed.

Signal generation devices including an auto-tuning electronic circuit module for generating tuned output signals are disclosed. The auto-tuning electronic circuit module may include a tunable resonant electronic circuit element for providing a tuned output signal, including a voltage divider element and a tuning array element and control element.

An oscillator includes a tunable resonant circuit having an inductance and a variable capacitance coupled between first and second nodes, and a set of capacitances selectively coupleable between the first and second nodes. An input control node receiving an input control signal is coupled to the variable capacitance and set of capacitances. The tunable resonant circuit is tunable based on the input control signal. A biasing circuit biases the tunable resonant circuit to generate a variable-frequency output signal between the first and second nodes. A voltage divider generates a set of different voltage thresholds, and a set of comparator circuits with hysteresis compares the input control signal to the set of different voltage thresholds to generate a set of control signals. The capacitances in the set of capacitances are selectively coupleable between the first and second nodes as a function of control signals in the set of control signals.

A tunable inductor arrangeable on a chip or substrate comprises a first winding part connected at one end to a first input of the tunable inductor arrangement, a second winding part connected at one end to the other end of the first winding part, a third winding part connected at one end to a second input of the tunable inductor arrangement, a fourth winding part connected at one end to the other end of the third winding part, and a switch arrangement arranged. The switch arrangement tunes the tunable inductor by selectively connecting the first and fourth winding parts in parallel and the second and third winding parts in parallel, with the parallel couplings in series between the first and second inputs, or connecting the first, second, fourth and third winding parts in series between the first and second inputs. Corresponding transceivers, communication devices, methods and computer programs are disclosed.

A system is described for maintaining an inductive-capacitive (LC) network at resonance while the excitation frequency may be varied between a number of discrete frequencies at desired instants controlled by a modulation input, while taking into account component parameter errors due environmental and ageing as well as manufacturing tolerances. Control of the resonance while the excitation frequency changes permits the transmission of frequency modulation (FM) or frequency shift keying (FSK) information through an inductively coupled power transfer system.

A system is described for maintaining an inductive-capacitive (LC) network at resonance while the excitation frequency may be varied between a number of discrete frequencies at desired instants controlled by a modulation input, while taking into account component parameter errors due environmental and ageing as well as manufacturing tolerances. Control of the resonance while the excitation frequency changes permits the transmission of frequency modulation (FM) or frequency shift keying (FSK) information through an inductively coupled power transfer system.

An impedance tuning circuit includes a first node and a second node, and an inductance circuit including an inductor and a first switch connected in series such that the inductor is connected to the first node and the first switch is connected to the second node. The inductance circuit further includes a second switch implemented between ground and a third node between the inductor and the first switch, such that the inductance circuit is capable of providing a series inductance path between the first and second nodes or a shunt inductance path between the third node and the ground.

Disclosed herein is a tunable resonant circuit including an inductance directly electrically connected in series between first and second nodes, a variable capacitance directly electrically connected between the first and second nodes, and a set of switched capacitances coupled between the first and second nodes. The set of switched capacitances includes a plurality of capacitance units, each capacitance unit comprising a first capacitance for that capacitance unit directly electrically connected between the first node and a switch and a second capacitance for the capacitance unit directly electrically connected between the switch and the second node. Control circuitry is configured to receive an input control signal and connected to control the switches of the set of switched capacitances. A biasing circuit is directly electrically connected to the tunable resonance circuit at the first and second nodes.

A tuner circuit includes a DC (Direct Current) cut-off unit configured to cut off a DC component in a signal received from an antenna, a switching unit configured to transmit the signal by being turned on when a bias voltage is applied, a high pass filter unit configured to pass only a high frequency component in a signal having passed the switching unit, and a low noise amplifier configured to output a signal having passed a high frequency filter by amplifying the signal.

Embodiments of radio frequency (RF) front-end circuitry are disclosed where the RF front-end circuitry includes a tunable RF filter structure and a calibration circuit. The tunable RF filter structure includes (at least) a pair of weakly coupled resonators and defines a transfer function with a passband. The calibration circuit is configured to shape the passband so that the passband defines a center frequency. Additionally, the calibration circuit is configured to detect a phase difference at the target center frequency between the pair of weakly coupled resonators and adjust the phase difference of the pair of weakly coupled resonators at the target center frequency so as to reduce a frequency displacement between the center frequency of the passband and the target center frequency. In this manner, the calibration circuit calibrates the tunable RF filter structure to correct for errors in the center frequency of the passband due to component manufacturing variations.