An RF-Band Adaptive Predistorter Power Amplifier

Yoshitaka SETO
Yoshihiko AKAIWA

IEICE TRANSACTIONS on Communications   Vol.E85-B    No.12    pp.2726-2731
Publication Date: 2002/12/01
Online ISSN: 
Print ISSN: 0916-8516
Type of Manuscript: Special Section PAPER (Special Issue on Software Defined Radio Technology and Its Applications)
nonlinear distortion,  adaptive predistorter,  out-of-band radiation power,  

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A basestation power amplifier requires high linearity and stable operation for common amplification of a multiplexed wideband signal. Nonlinearity compensation techniques with the feedforward or predistorter are useful for this purpose. This paper presents a predistortion amplifier with automatic control at RF band for application at a basestation. In this method, the predistorter distorts an RF input signal by referring to a look-up table (LUT) corresponding to the input power. Out-of-band radiation power are directly monitored at IF band to determine the LUT. A DSP with an iterative algorithm updates the content of the LUT to minimize the out-of-band radiation power. Computer simulation experiment is carried out. The use of this proposed method promises a highly linear wideband and high power-efficiency amplifier.