Title :
Improved output spectrum of linearized class-F power amplifier for digital cellular mobile communications
Author :
Aoki, N. ; Asano, Y. ; Minowa, M. ; Takano, T.
Author_Institution :
Fujitsu Labs. Ltd., Radio & Satellite Commun. Syst. Lab., Kawasaki, Japan
fDate :
29 Sep-1 Oct 1992
Abstract :
Describes a class-F power amplifier with an amplitude distortion canceller for a cellular mobile communications terminal. The output spectrum of the power amplifier was calculated for a π/4-shifted QPSK input signal. Calculated and measured spectra were in close agreement. Out-of-band emission of the power amplifier output spectrum is subject to both AM-AM and AM-PM conversion. The effects of AM-AM conversion can be mitigated by using an amplitude linearizer; however, AM-PM conversion is not compensated. Out-of-band emission levels were calculated as a function of AM-PM conversion to provide an estimation of allowable AM-PM conversion for a class-F power amplifier module. Calculations and measurement clarified that even a class-F power amplifier module having a phase variation of 10 to 15 degrees due to AM-PM conversion transmits a spectrum that satisfies the out-of-band emission standard
Keywords :
cellular radio; digital radio systems; phase shift keying; power amplifiers; radiofrequency amplifiers; spectral analysis; π/4-shifted QPSK input signal; AM-AM conversion; AM-PM conversion; amplitude distortion canceller; amplitude linearizer; digital cellular mobile communications; linearized class-F power amplifier; out of band emission; output spectrum; phase variation; Autocorrelation; Costs; Distortion measurement; Laboratories; Mobile communication; Nonlinear distortion; Power amplifiers; Power measurement; Quadrature phase shift keying; Voltage;
Conference_Titel :
Universal Personal Communications, 1992. ICUPC '92 Proceedings., 1st International Conference on
Conference_Location :
Dallas, TX
Print_ISBN :
0-7803-0591-4
DOI :
10.1109/ICUPC.1992.240774
