An 60 W Average Power Wideband Amplifier with Envelope Tracking for DVB-T Applications

In this paper, the development of a DVB-T power amplifier (PA) with enhanced efficiency performance based on the envelope tracking method (ET) is described. The amplifier works in the ultrahigh frequency (UHF) hand from 470 to 803 MHz. The PA consists of two coupled push-pull stages of laterally diffused metal oxide semiconductors (LDMOS) that are combined and equipped with a multilevel Supply Modulator to achieve a drain modulation. The results indicate an improved drain efficiency within 14.6 % up to eta >= 42 % for a 8 MHz coded orthogonal frequency division multiplexing (COFDM) - signal with 9 dB peak-to-average power ratio (PAPR) including the losses of the Supply Modulator. While fulfilling the spectrum mask, the output power is higher than 60 W (470 W peak) for the frequency range from 470 - 803 MHz.