R. Hajji et al., MULTITONE POWER AND INTERMODULATION LOAD-PULL CHARACTERIZATION OF MICROWAVE TRANSISTORS SUITABLE FOR LINEAR SSPAS DESIGN, IEEE transactions on microwave theory and techniques, 45(7), 1997, pp. 1093-1099
In this paper, an experimental load-pull characterization of microwave
transistors operated under N-tone excitations (2 less than or equal t
o N less than or equal to 32) is presented, Such characterization is v
ery useful to investigate the linearity of high-power amplifiers via i
ntermodulation distortion analysis, All the measurements were carried
out using a newly developed multiline measurement system which uses an
arbitrary waveform generator (AWG) to generate the spectrum of any N
desired tones and a microwave transition analyzer (MTA) as a vector re
ceiver, The measured intermodulation rejection (IMR) behavior, as the
number of tones increases, is compared with previously published theor
etical results, Constant output power contours and IMR contours in the
Gamma(L)(f(0)) plane for different number of tones are presented and
discussed, The dependency of the LMR on the biasing conditions and the
carriers' phase distribution is also investigated.