Title :
A simple and effective RF predistorter for use in the HPAs of base stations in cellular mobile systems
Author :
Xiao, M.X. ; Cheung, S.W. ; Yuk, T.I.
Author_Institution :
Dept. of Electr. & Electron. Eng., Univ. of Hong Kong, Hong Kong, China
Abstract :
This paper presents the design of using a simple mixer circuit, constructed with Schottky diodes as the nonlinear device, to generate the intermodulation (IM) products for predistortion of high-power amplifiers (HPAs) in the base stations of cellular mobile systems. The design has a simple structure and requires no external dc bias voltage. A complex polynomial is used to model the characteristic of the HPA and the predistorter generates the in-phase and quadrature components of the intermodulation distortion (IMD) products for predistortion of the HPA. Experimental results using a practical HPA show that, for a modulated CDMA (IS-95) signal, the predistorter can reduce the adjacent-channel-power ratio (ACPR) by 15 dB.
Keywords :
Schottky diodes; cellular radio; code division multiple access; intermodulation distortion; mixers (circuits); radiofrequency amplifiers; telecommunication channels; HPA; RF predistorter; Schottky diodes; adjacent-channel-power ratio; cellular mobile systems; high-power amplifiers; intermodulation distortion; modulated CDMA; Base stations; Character generation; Circuits; High power amplifiers; Polynomials; Predistortion; Radio frequency; Radiofrequency amplifiers; Schottky diodes; Voltage; Adjacent-channel-power ratio (ACPR); High Power Amplifier; Inter-modulation; Mixer; RF Analog Predistorter;
Conference_Titel :
Communication Systems, 2008. ICCS 2008. 11th IEEE Singapore International Conference on
Conference_Location :
Guangzhou
Print_ISBN :
978-1-4244-2423-8
Electronic_ISBN :
978-1-4244-2424-5
DOI :
10.1109/ICCS.2008.4737296
