Development of an MCPA using digital pre-distortion for digital terrestrial TV broadcasting

This article describes development and construction of an evolutional MCPA (multi-channel power amplifier) using digital pre-distortion for digital terrestrial TV broadcasting. In this equipment, a wide-band of 50 MHz and over, is produced by using a high-speed A/D and D/A converter with a sampling frequency of 200 MHz and more. We also developed a new method that detects PA distortion by adding the RF output signal and inverted RF input signal to reduce the dynamic range and new algorithm to compensate with a high speed. Using these new methods, we obtained IMs of -50 dB and under with multiple channel inputs and much higher efficiency than conventional ones. This technology also can be applied for designing amplifiers in the GHz band because its theory of principle does not depend on operating frequencies.