Digital power amplifier with RF sampling rate and wide tuning range

A method comprising:

• generating a differential signal based on a received amplitude code and a clock signal, wherein the generating is performed by a input circuit of a switching amplifier, and wherein a frequency of the clock signal is a radio frequency (RF) of a transmitter circuit;
• converting the differential signal to a single-ended signal using a conversion circuit of the switching amplifier, wherein converting the differential signal includes:
• providing the differential signal to first and second sub-coils of an inductive-capacitive (LC) tuning circuit, the LC tuning circuit including a variable capacitor coupled between the first and second sub-coils;
• transferring energy, via mutual inductance, from the first and second sub-coils to third and fourth sub-coils of LC tuning circuit;
• and
• outputting the signal-ended signal on an output node coupled to one of the third and fourth sub-coils;
• and
• causing an antenna to wirelessly transmit an amplitude modulated (AM) signal received from the conversion circuit.

An apparatus comprising:

• a digital filter configured to generate an amplitude code having a plurality of bit including a sign bit indicative of a sign of the amplitude, and a subset of magnitude bits indicative of a magnitude of the amplitude;
• and
• a switching amplifier circuit configured to generate an amplitude modulated (AM) signal for transmission, at a radio frequency (RF), via an antenna, wherein the AM signal is based on the amplitude code, and wherein switching amplifier circuit includes:
• a local oscillator circuit configured to generate a clock signal at the RF;
• an input circuit configured to generate a differential signal based on the amplitude code and the clock signal;
• and
• a differential-to-single-ended conversion circuit configured to generate the AM signal, using the differential signal, as a single-ended signal, the differential-to-single-ended circuit including an inductive-capacitive (LC) tuning circuit having a first sub-coil, a second sub-coil, and a first capacitor coupled in series between the first sub-coil and the second sub-coil;
• wherein the differential-to-single ended conversion circuit is further configured to convey the AM signal to the antenna for transmission.