A Practical Class S Power Amplifier for High Frequency Transmitters

Digital signal processing (DSP) techniques are being incorporated in the design of modern power amplifiers (PA) and as the speed of DSP advances it is envisioned that DSP will develop to a point where algorithms will provide signals at RF particularly for switching amplifiers. The digital transmitter has many potential benefits such as the absence of aging or tuning problems, reconfigurability, programmability as well as ease of integration and testing. In this paper a new class S RF power amplifier architecture is proposed for use in high frequency transmitters and is not restricted by the requirement for the square wave modulator to have a sampling rate of 4 times the carrier frequency.

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