Abstract: A circuit device includes a directional coupler with a first port receiving a radiofrequency signal, a second port outputting a signal in response to signal received by the first port, and a third port outputting a signal in response to a reflection of the signal at the second port. An impedance matching network is connected between the second port and an antenna. The impedance matching network includes fixed inductive and capacitive components and a single variable inductive or capacitive component. A diode coupled to the third port of the coupler generates a voltage at a measurement terminal which is processed in order to select and set the inductance or capacitance value of the variable inductive or capacitive component.

Abstract: A circuit device includes a directional coupler with a first port receiving a radiofrequency signal, a second port outputting a signal in response to signal received by the first port, and a third port outputting a signal in response to a reflection of the signal at the second port. An impedance matching network is connected between the second port and an antenna. The impedance matching network includes fixed inductive and capacitive components and a single variable inductive or capacitive component. A diode coupled to the third port of the coupler generates a voltage at a measurement terminal which is processed in order to select and set the inductance or capacitance value of the variable inductive or capacitive component.

Abstract: A circuit device includes a directional coupler with a first port receiving a radiofrequency signal, a second port outputting a signal in response to signal received by the first port, and a third port outputting a signal in response to a reflection of the signal at the second port. An impedance matching network is connected between the second port and an antenna. The impedance matching network includes fixed inductive and capacitive components and a single variable inductive or capacitive component. A diode coupled to the third port of the coupler generates a voltage at a measurement terminal which is processed in order to select and set the inductance or capacitance value of the variable inductive or capacitive component.

Abstract: A circuit device includes a directional coupler with a first port receiving a radiofrequency signal, a second port outputting a signal in response to signal received by the first port, and a third port outputting a signal in response to a reflection of the signal at the second port. An impedance matching network is connected between the second port and an antenna. The impedance matching network includes fixed inductive and capacitive components and a single variable inductive or capacitive component. A diode coupled to the third port of the coupler generates a voltage at a measurement terminal which is processed in order to select and set the inductance or capacitance value of the variable inductive or capacitive component.

Abstract: A digital-to-analog converter (DAC) and a method for operating the DAC are disclosed. The DAC receives, over a first channel, a control signal that is transmitted in accordance with a binary protocol. The DAC also receives, over a second channel different than the first channel, data that is transmitted in accordance with a multilevel communication protocol that is different than the binary protocol. The DAC determines a plurality of first and second voltages based on the received data and identifies, based on the control signal, a time when data transmission or reception is switched between first and second antennas. In response to identifying, based on the control signal, the time when data transmission or reception is switched, the DAC outputs the determined plurality of first voltages to a first antenna tuning circuit or the determined plurality of second voltages to a second antenna tuning circuit.

Abstract: A resonant circuit can be used in recharging a battery. The resonant circuit includes an inductor, a first capacitor in series with the inductor, and a second capacitor in parallel with the inductor. Upon entering the field of a charging terminal a controller connected to the resonant circuit continually measures loss in the inductor and voltage on a terminal of the resonant circuit. If both are below respective predetermined thresholds, the controller decreases the capacitance of the first capacitor and increases the capacitance of the second capacitor, thereby increasing voltage from the resonant circuit to the battery.

Abstract: A digital-to-analog converter (DAC) and a method for operating the DAC are disclosed. The DAC receives, over a first channel, a control signal that is transmitted in accordance with a binary protocol. The DAC also receives, over a second channel different than the first channel, data that is transmitted in accordance with a multilevel communication protocol that is different than the binary protocol. The DAC determines a plurality of first and second voltages based on the received data and identifies, based on the control signal, a time when data transmission or reception is switched between first and second antennas. In response to identifying, based on the control signal, the time when data transmission or reception is switched, the DAC outputs the determined plurality of first voltages to a first antenna tuning circuit or the determined plurality of second voltages to a second antenna tuning circuit.

Abstract: A digital-to-analog converter (DAC) and a method for operating the DAC are disclosed. The DAC receives, over a first channel, a control signal that is transmitted in accordance with a binary protocol. The DAC also receives, over a second channel different than the first channel, data that is transmitted in accordance with a multilevel communication protocol that is different than the binary protocol. The DAC determines a plurality of first and second voltages based on the received data and identifies, based on the control signal, a time when data transmission or reception is switched between first and second antennas. In response to identifying, based on the control signal, the time when data transmission or reception is switched, the DAC outputs the determined plurality of first voltages to a first antenna tuning circuit or the determined plurality of second voltages to a second antenna tuning circuit.

Abstract: A digital-to-analog converter (DAC) and a method for operating the DAC are disclosed. The DAC receives, over a first channel, a control signal that is transmitted in accordance with a binary protocol. The DAC also receives, over a second channel different than the first channel, data that is transmitted in accordance with a multilevel communication protocol that is different than the binary protocol. The DAC determines a plurality of first and second voltages based on the received data and identifies, based on the control signal, a time when data transmission or reception is switched between first and second antennas. In response to identifying, based on the control signal, the time when data transmission or reception is switched, the DAC outputs the determined plurality of first voltages to a first antenna tuning circuit or the determined plurality of second voltages to a second antenna tuning circuit.

Abstract: A resonant circuit can be used in recharging a battery. The resonant circuit includes an inductor, a first capacitor in series with the inductor, and a second capacitor in parallel with the inductor. Upon entering the field of a charging terminal a controller connected to the resonant circuit continually measures loss in the inductor and voltage on a terminal of the resonant circuit. If both are below respective predetermined thresholds, the controller decreases the capacitance of the first capacitor and increases the capacitance of the second capacitor, thereby increasing voltage from the resonant circuit to the battery.