Low-distortion class S power amplifier with constant-impedance bandpass filter

摘要

An amplification system and an integrated circuit include a bandpass filter and an amplifier. The bandpass filter filters an input digital bitstream or an amplified signal to provide a filtered signal. The bandpass filter exhibits constant input impedance over a passband associated with the input digital bitstream, and a stopband associated with shaped-noise energy, thereby increasing signal-to-noise ratio and/or signal-to-distortion ratio associated with the filtered signal. The amplifier amplifies at least one of the filtered signal and the input digital bitstream to provide the amplified signal. A method of providing amplification includes bandpass filtering an input digital bitstream or an amplified signal to provide a filtered signal, providing constant input impedance over a passband and a stopband by the bandpass filtering, and amplifying at least one of the filtered signal and the input digital bitstream to provide the amplified signal.

主权项

1. An amplification system, comprising:
a bandpass filter operative to filter at least one of an input digital bitstream and an amplified signal and to generate a filtered signal, the bandpass filter being configured to provide constant input impedance over a passband associated with the input signal, the bandpass filter being configured to provide constant input impedance over a stopband associated with shaped-noise energy, thereby increasing at least one of signal-to-noise ratio and signal-to-distortion ratio associated with the filtered signal; and an amplifier coupled with the bandpass filter, the amplifier amplifying at least one of the filtered signal and the input digital bitstream to provide the amplified signal; wherein the input digital bitstream comprises at least one of a Long Term Evolution (LTE) bitstream set and a Two-tone bitstream set.