A resonant matching circuit (310) for matching a resonant frequency of a wireless power transfer system to a frequency of a power signal comprises a switch (311) connected in parallel with a resonant element (302) of the wireless power transfer system; and a controller (312) connected to the switch (311) and configured to detect a zero-voltage level crossing of a signal flowing through the resonant element (302) and to close the switch (311) for a predefined amount of time upon detection of the zero-voltage level crossing, wherein closing the switch (311) for the predefined amount of time adds any one of an inductive value and a capacitive value to the resonant frequency of a wireless power transfer system.

A resonant matching circuit (310) for matching a resonant frequency of a wireless power transfer system to a frequency of a power signal comprises a switch (311) connected in parallel with a resonant element (302) of the wireless power transfer system; and a controller (312) connected to the switch (311) and configured to detect a zero-voltage level crossing of a signal flowing through the resonant element (302) and to close the switch (311) for a predefined amount of time upon detection of the zero-voltage level crossing, wherein closing the switch (311) for the predefined amount of time adds any one of an inductive value and a capacitive value to the resonant frequency of a wireless power transfer system.

Disclosed is an integrated circuit for a near-field radio, including an oscillator configured to output a carrier frequency, an inductor capacitor (LC) tank antenna circuit configured to resonate at a resonance frequency, a frequency measuring circuit configured to measure the resonance frequency of the LC tank antenna circuit and compare the resonance frequency to the carrier frequency, and a controller to adjust the frequency of the LC tank antenna circuit to the carrier frequency.

The invention relates to a method for radio communication using one or more tunable antennas and an antenna tuning apparatus, and to an apparatus for radio communication using one or more tunable antennas and an antenna tuning apparatus. An apparatus for radio communication of the invention comprises: 4 antennas, each of the antennas being a tunable passive antenna; a radio device; an antenna tuning apparatus having 4 antenna ports, each of the antenna ports being coupled to one of the antennas through a feeder, the antenna tuning apparatus having 4 radio ports, each of the radio ports being coupled to the radio device through an interconnection; and a tuning control unit, the tuning control unit receiving a tuning instruction generated automatically within the apparatus for radio communication, the tuning control unit delivering a plurality of tuning control signals to the antenna tuning apparatus and to the tunable passive antennas.

The invention relates to a method for radio communication using multiple antennas and localization variables, and to an apparatus for radio communication using multiple antennas and localization variables. An apparatus for radio communication of the invention comprises: 4 antennas, the 4 antennas forming an antenna array; a radio device; a sensor unit estimating a plurality of localization variables; an antenna tuning apparatus having 4 antenna ports, each of the antenna ports being coupled to one of the antennas through a feeder, the antenna tuning apparatus having 4 radio ports, each of the radio ports being coupled to the radio device through an interconnection; and a tuning control unit, the tuning control unit receiving a tuning instruction generated automatically within the apparatus for radio communication, the tuning control unit delivering a plurality of tuning control signals to the antenna tuning apparatus.

The present disclosure relates to a front-end system for a radio device. In one example, a front-end system comprises a converter, the converter comprising a mixer configured for down-converting a radio frequency signal into a baseband signal by using a local oscillator signal generated by a signal generator, and characterized in that, the converter further comprises a quantizer arranged for quantizing the baseband signal into a digital signal. Further, the signal generator may be configured for generating, based on the digital signal, the local oscillator signal such that it is synchronized with the radio frequency signal.

A broadcast receiver includes a processor that processes a broadcasting signal, a detector that detects a level of a signal of a first predetermined band of the broadcasting signal, and an adjuster that adjusts at least one of a characteristic and an operation of the processor based on the detected level.

In some implementations, a control system for a resonating element comprises: a resonating element being driven by an oscillating drive signal and configured to generate a sense signal proportional to an amplitude of motion; a phase comparator coupled to the resonating element and to an oscillating drive signal, the phase comparator configured to compare the sense signal and the oscillating drive signal and to generate an error signal proportional to the phase difference; an oscillator coupled to the phase comparator and configured for generating the oscillating drive signal, the oscillator configured to receive the error signal and to adjust a phase of the oscillating signal based on the error signal; and an automatic gain control coupled to the resonating element and the oscillator, the automatic gain control configured to adjust the gain of the oscillating drive signal based on the signal generated by the resonating element.

Apparatus and methods are disclosed related to tuning a resonant frequency of an LC circuit. In some implementations, the LC circuit can be embodied in a low noise amplifier (LNA) of a receiver. The receiver can include a component configured to generate an indicator of received signal strength indication (RSSI) of a radio frequency (RF) signal received by the receiver. A control block can adjust the resonant frequency of the LC circuit based at least in part on the indicator of RSSI. As another example, the receiver can include an oscillator, such as a VCO, separate from the LC circuit that can be used to tune the resonant frequency of the LC circuit. These apparatus can compensate for variation in a zero imaginary component of an impedance across the LC circuit.

Systems and methods for performing automatic frequency control are provided. Instead of relying on individual frequency tuners for each channel of a multi-channel receiver system, the present subject matter uses a single frequency tuner for receiving each channel of the multi-channel receiver system. A locked demodulator may be designated as a reference demodulator and frequency offset values associated with the reference demodulator may be applied to other demodulators of the multi-channel receiver. These frequency offset values may be used by individual demodulators of each channel for correcting corresponding frequency offsets.