Title :
A Comprehensive Analysis of AM–AM and AM–PM Conversion in an LDMOS RF Power Amplifier
Author :
Aikio, Janne P. ; Rahkonen, Timo
Author_Institution :
Dept. of Electr. & Inf. Eng. & Infotech Oulu, Univ. of Oulu, Oulu
Abstract :
In this paper, a Volterra analysis built on top of a normal harmonic balance simulation is used for a comprehensive analysis of the causes of AM-PM distortion in a LDMOS RF power amplifier (PA). The analysis shows that any nonlinear capacitors cause AM-PM. In addition, varying terminal impedances may pull the matching impedances and cause phase shift. The AM-PM is also affected by the distortion that is mixed down from the second harmonic. As a sample circuit, an internally matched 30-W LDMOS RF PA is used and the results are compared to measured AM-AM, AM-PM and large-signal S11.
Keywords :
Volterra equations; power amplifiers; AM-AM conversion; AM-PM conversion; AM-PM distortion; LDMOS RF power amplifier; Volterra analysis; matching impedances; nonlinear capacitors; normal harmonic balance simulation; phase shift; terminal impedances; AM–AM; AM–PM; RF power amplifier (PA); Volterra analysis; distortion analysis; polynomial device model;
Journal_Title :
Microwave Theory and Techniques, IEEE Transactions on
DOI :
10.1109/TMTT.2008.2011161
