Title :
An IC for linearizing RF power amplifiers using envelope elimination and restoration
Author :
Su, David K. ; McFarland, William J.
Author_Institution :
Hewlett-Packard Co., Palo Alto, CA, USA
fDate :
12/1/1998 12:00:00 AM
Abstract :
This paper presents a monolithic CMOS implementation of an envelope elimination and restoration linearization system that improves the linearity of efficient radio-frequency power amplifiers. The linearization IC, which occupies 4.3 mm2 when implemented in a 0.8-μm CMOS technology, consists of a limiter, envelope detectors, and delta-modulated switching power supply. This circuit was used to linearize advanced mobile phone system cellular power amplifiers transmitting North American digital cellular (NADC) waveforms. Measurements show that the linearized outputs meet the spectral mask and phase distortion requirements of NADC. The linearization system can improve the overall efficiency from 36 to 49%, while increasing the maximum linear output power from 26.5 to 29.5 dBm
Keywords :
CMOS analogue integrated circuits; UHF integrated circuits; UHF power amplifiers; cellular radio; delta modulation; electric distortion; limiters; linearisation techniques; 0.8 micron; 49 percent; CMOS implementation; North American digital cellular waveforms; RF power amplifiers; cellular power amplifiers; delta-modulated switching power supply; envelope elimination; envelope restoration; limiter; linearization system; maximum linear output power; mobile phone system; phase distortion; spectral mask; CMOS integrated circuits; CMOS technology; Envelope detectors; Linearity; Power amplifiers; Power supplies; Power system restoration; Radio frequency; Radiofrequency amplifiers; Radiofrequency integrated circuits;
Journal_Title :
Solid-State Circuits, IEEE Journal of
