A Study of memory effects of RF power LDMOS before and after digital predistortion

Author

Landin, Per N. ; Isaksson, Magnus ; Keskitalo, Niclas ; Tornblad, Olof

Author_Institution

Center for RF Meas. Technol., Univ. of Gdvle, Gdvle, Sweden

fYear

2009

fDate

20-21 April 2009

Firstpage

1

Lastpage

5

Abstract

Sideband asymmetries in distortion products are created due to electrical and thermal memory effects and this can be difficult to correct for in a digital predistortion algorithm. In this study, sideband asymmetries in third-order intermodulation distortion products before and after digital predistortion were investigated using 2-tone and 2-carrier WCDMA signals. The parallel Hammerstein (PH) model was used in the digital predistortion algorithm. The sign of the asymmetries before correction were found to depend on power level. Memoryless correction lead to an increase in asymmetries for some power ranges whereas using a PH model of order 13 with only one order of memory length lead to good correction over a large power range.

Keywords

power MOSFET; 2-carrier WCDMA signal; 2-tone WCDMA signal; RF power LDMOS; digital predistortion algorithm; electrical memory effect; parallel Hammerstein model; sideband asymmetries; thermal memory effect; third-order intermodulation distortion product; Bandwidth; Frequency measurement; Microcomputers; Multiaccess communication; Power amplifiers; Power measurement; Predistortion; Radio frequency; Radiofrequency amplifiers; Signal processing algorithms;

fLanguage

English

Publisher

ieee

Conference_Titel

Wireless and Microwave Technology Conference, 2009. WAMICON '09. IEEE 10th Annual

Conference_Location

Clearwater, FL

Print_ISBN

978-1-4244-4564-6

Electronic_ISBN

978-1-4244-4565-3

Type

conf

DOI

10.1109/WAMICON.2009.5207289

Filename

5207289