Abstract: A method for transmitting radio frequency (RF) signals is provided. In-phase (I) and quadrature (Q) signals are received and filtered using sigma-delta modulation. I and Q pulse width modulation signals are generated from the filtered I and Q signals and interleaved so as to generate a time-interleaved signal. The time-interleaved signal is then amplified to generate the RF signals.

Abstract: A method for generating an amplified radio frequency (RF) signal is provided. In-phase (I) and quadrature (Q) signals are received and interleaved so as to generate a time-interleaved signal. Delayed time-interleaved signals are then generated from the time interleaved signal, and each of the delayed time-interleaved signals is amplified so as to generate a plurality of amplified signals. The amplified signals are then combined with a transformer, where the delayed time-interleaved signals are arranged to generate a filter response with the transformer.

Abstract: A method is provided. A noise shaped signal having a plurality of instants is generated with each instant being associated with at least one of a plurality of output levels. A next phase is selected for each instant, where each next phase is a circularly shifted phase based at least in part on a previous phase for the associated output level for its instant. A plurality of PWM signals is then generated using the phase for each instant, and an amplified signal is generated from the plurality of PWM signals.

Abstract: A class D power amplifier (PA) is provided. The PA generally comprises a driver, output capacitor, a matching network, and a cancellation circuit. The driver has an input, an output, and a parasitic capacitance, and the input of the driver is configured to receive complementary first and second radio frequency (RF) signals, where there is a free-fly interval between consecutive pulses from the first and second RF signals. The output capacitor and cancellation circuit are each coupled to the output of the driver such that the cancellation circuit provides harmonic restoration at least during the free-fly interval, and the matching network is coupled to the output capacitor.

Abstract: A class D power amplifier (PA) is provided. The PA generally comprises a driver, output capacitor, a matching network, and a cancellation circuit. The driver has an input, an output, and a parasitic capacitance, and the input of the driver is configured to receive complementary first and second radio frequency (RF) signals, where there is a free-fly interval between consecutive pulses from the first and second RF signals. The output capacitor and cancellation circuit are each coupled to the output of the driver such that the cancellation circuit provides harmonic restoration at least during the free-fly interval, and the matching network is coupled to the output capacitor.

Abstract: Systems and methods may be provided for a LINC system having a level-shifting LINC amplifier. The systems and methods may include a dynamic power supply that is adjustable to provide at least a first voltage supply level and a second voltage supply level higher than the first voltage supply level; a first power amplifier that amplifies a first component signal to generate a first amplified signal; a second power amplifier that amplifiers a second component signal to generate a second amplified signal, where the first component signal and the second component signal are components of an original signal, where the first component signal and the second component signal each have a constant envelope, and where the original signal has a non-constant envelope, and where the first and second power amplifiers are biased at the first voltage supply level or the second voltage supply level based upon an analysis of an amplitude of the original signal.