High-efficiency 400 W power amplifier with dynamic drain voltage control for 6 MHz OFDM signal

Abstract

In this paper, we present a high-efficiency 400 W power amplifier (PA) for a 6 MHz orthogonal frequency division multiplexing (OFDM) signal with a 10 dB peak-to-average power ratio (PAPR). To improve the efficiency of the PA at a 10 dB backoff from its saturated output power (PSAT), a dynamic drain voltage control is applied, which supplies two different drain voltages depending on the envelope of the OFDM signal. The PA is fabricated using a 400 W push-pull laterally diffused metal oxide semiconductor (LDMOS) field-effect transistor (FET) for an ultrahigh frequency (UHF) band. The drain current of a single LDMOS FET is 9.5 A at PSAT' The drain voltages used in the control are set to 40 V and 20 V. Measurement results indicate a power-added efficiency (PAE) in the case of dynamic drain voltage control of 34%, which is 15% higher than PAE at a drain voltage of 40 V. This is the highest output power of a PA with a dynamic drain voltage control to the best of our knowledge.

Inductor‐less envelope modulated radio frequency power amplifier using stacked amplifiers and envelope shaping

“…To achieve a higher efficiency would require a split band architecture [3], which is considerably more complex and less linear. The watt-level P OUT of this work is higher than previously published single band modulated RF PA with the exception of [8] which exhibits significantly higher distortion.…”

“…The efficiency of the basic class B amplifier modulator can be increased by adopting class G [5,6], class H [7] or power supply switching [8,9] techniques as shown in Fig. 1b.…”

A 10-W S-band class-B GaN amplifier with a dynamic gate bias circuit for linearity enhancement

“…Envelope tracking technique remains an important field of investigation to propose high-efficiency and linear amplification solutions with a major challenge to design highcurrent, high-efficiency and wideband drain bias modulators [2][3][4][5][6].…”