Title :
Estimation of error vector magnitude using two-tone intermodulation distortion measurements [power amplifier]
Author :
Hyunchul Ku ; Kenney, J.S.
Author_Institution :
Sch. of Electr. & Comput. Eng., Georgia Inst. of Technol., Atlanta, GA, USA
Abstract :
In this paper, a new method for estimating error vector magnitude (EVM) degradation of a power amplifier using the intrinsic kernel function derived from two-tone intermodulation distortion (IMD) measurements is presented. The kernel function represents the incremental distortion characteristics of the power amplifier driven by a signal with small amplitude deviation. With a knowledge of the complementary cumulative distribution function (CCDF) of an arbitrary input signal, the Carrier-to-Interference Ratio (CIR) of the power amplifier can be derived and the EVM degradation of the power amplifier may be calculated. For the experimental validation, the EVM of the 16-QAM signals passed through 1.9 GHz HFET nonlinear amplifier is derived by the suggested method and compared with the measured results. The derived EVM shows a good agreement with measured results. The r.m.s. error between the two results over a 20 dB input range is less than 2%.
Keywords :
error analysis; intermodulation distortion; nonlinear network analysis; power amplifiers; radiofrequency amplifiers; 1.9 GHz; 16-QAM digital signals; CIR; HFET nonlinear amplifier; carrier-to-interference ratio; complementary cumulative distribution function; error vector magnitude estimation; intermodulation distortion measurements; intrinsic kernel function; nonlinear power amplifier; two-tone IMD measurements; Degradation; Distortion measurement; Distributed amplifiers; Distribution functions; Estimation error; Intermodulation distortion; Kernel; Nonlinear distortion; Power amplifiers; Power measurement;
Conference_Titel :
Microwave Symposium Digest, 2001 IEEE MTT-S International
Conference_Location :
Phoenix, AZ, USA
Print_ISBN :
0-7803-6538-0
DOI :
10.1109/MWSYM.2001.966829
