Feedback Receiver for Antenna Tuner Calculations

A method, comprising:

• generating a baseband signal;
• converting the baseband signal to a radio frequency (RF) signal transmitted via an RF antenna;
• comparing an amplitude of the baseband signal to a selection corridor, wherein if the amplitude is within the selection corridor a corresponding amplitude and phase sample of the RF signal is accumulated in a memory element;
• calculating and storing average values of the amplitude and phase samples accumulated over a time period;
• and
• adjusting an admittance of an antenna tuner to set a matching condition between the antenna tuner and the RF antenna based on the average values of the amplitude and phase samples.

A transmitter, comprising:

• a baseband signal generator configured to generate a baseband signal;
• a transmission path configured to convert the baseband signal to a radio frequency (RF) signal and to provide the RF signal to an RF antenna;
• an antenna tuner coupled downstream of the transmission path;
• a threshold comparator configured to generate a trigger signal at an output node if an amplitude of the baseband signal is within a selection corridor defined by upper and lower threshold values;
• a memory element configured to accumulate amplitude and phase samples of the RF signal during clock periods in which the trigger signal is generated;
• a counter configured to count a number of accumulated amplitude and phase samples during a time period comprising a plurality of clock periods;
• and
• a calculator configured to provide a control signal to tune the antenna tuner, wherein the control signal is based on average values of the accumulated amplitude and phase samples of a forward propagating wave and average values of the accumulated amplitude and phase samples of a reflected wave.