Detailed analysis of IMD in an LDMOS RF power amplifier

Author

Aikio, Janne P. ; Rahkonen, Timo

Author_Institution

Dept. of Electr. & Inf. Eng., Oulu Univ., Finland

fYear

2005

fDate

12-17 June 2005

Abstract

A detailed analysis of an LDMOS RF power amplifier is presented. Analysis shows that intermodulation distortion (IMD) sweet spot is a result of a vector sum of several cancelling mechanisms. This can make the sweet spot sensitive to center frequency and bandwidth. The analysis technique is implemented on top of harmonic-balance (HB) simulation. The simulated large-signal voltage and current spectra are used to fit polynomial models of the nonlinear I-V and Q-V sources of the device. The contributions of different nonlinearities can be calculated by using the polynomial model. The analysis relies on the accuracy of the simulation model, but the overall simulated results match well with the measurements.

Keywords

MIS devices; intermodulation distortion; polynomials; power amplifiers; radiofrequency amplifiers; LDMOS RF power amplifier; Volterra analysis; current spectra; distortion analysis; harmonic-balance simulation; intermodulation distortion; large-signal voltage; polynomial device model; polynomial models; Analytical models; Capacitors; Circuit simulation; Circuit testing; Curve fitting; Polynomials; Power amplifiers; Radio frequency; Radiofrequency amplifiers; Voltage control;

fLanguage

English

Publisher

ieee

Conference_Titel

Microwave Symposium Digest, 2005 IEEE MTT-S International

ISSN

01490-645X

Print_ISBN

0-7803-8845-3

Type

conf

DOI

10.1109/MWSYM.2005.1516788

Filename

1516788