A novel wideband active feedback amplifier linearization scheme suitable for handsets

Author

Nesimoglu, T. ; Canagarajah, C.N. ; McGeehan, J.P. ; Wilkinson, R.J.

Author_Institution

Centre for Commun. Res., Bristol Univ., UK

Volume

3

fYear

2000

fDate

2000

Firstpage

1712

Abstract

A new active feedback network is proposed for reducing intermodulation distortion (IMD). It is based on using the existing second harmonic zone (SHZ) distortion energy generated by the amplifier to predistort the input signals optimally to obtain a linear output. The technique is analyzed theoretically and practical results demonstrate the linearization performance. The measured two-tone test showed 23-dB reduction in the third-order intermodulation products (IMP₃), where π/4 DQPSK and W-CDMA gave up to 15-dB and 13-dB adjacent channel interference (ACI) suppression respectively. This technique differs from available active feedback techniques by performing both with narrow and wideband modulated signals. The linearization circuitry is simple and small in size

Keywords

UHF amplifiers; active networks; adjacent channel interference; code division multiple access; differential phase shift keying; feedback amplifiers; interference suppression; intermodulation distortion; linearisation techniques; mobile radio; quadrature phase shift keying; telephone sets; wideband amplifiers; π/4 DQPSK; 440 MHz; 450 MHz; IMD reduction; UHF; W-CDMA; active feedback network; adjacent channel interference suppression; handsets; input signal predistortion; intermodulation distortion reduction; linearization circuitry; linearization performance; measured two-tone test; narrowband modulated signals; second harmonic zone distortion energy; third-order intermodulation products; wideband active feedback amplifier linearization; wideband modulated signals; Broadband amplifiers; Distortion measurement; Feedback amplifiers; Harmonic distortion; Interchannel interference; Intermodulation distortion; Multiaccess communication; Performance analysis; Signal generators; Testing;

fLanguage

English

Publisher

ieee

Conference_Titel

Vehicular Technology Conference Proceedings, 2000. VTC 2000-Spring Tokyo. 2000 IEEE 51st

Conference_Location

Tokyo

ISSN

1090-3038

Print_ISBN

0-7803-5718-3

Type

conf

DOI

10.1109/VETECS.2000.851564

Filename

851564