Effects of different VDD-drives in ET & EER transmitters

Author

Rautio, Timo ; Harju, Henri ; Hietakangas, Simo ; Rahkonen, Timo

Author_Institution

Univ. of Oulu, Oulu

fYear

2007

fDate

19-20 Nov. 2007

Firstpage

1

Lastpage

4

Abstract

Envelope tracking (ET) technique transmitter employing a linear 0.5 W 1 GHz LDMOS PA (power amplifier) is studied. Four different methods for supply voltage modulation are discussed and measured results are given. Results show improvement both in efficiency and linearity when predistortion of the supply voltage is added. The same linear amplifier was used also in an envelope elimination and restoration (EER) system, and measurements show significant improvement in the linearity compared to the envelope tracking system, with no notable loss in the efficiency. Also the effect of feedthrough to the linearity was much lower than with a Class E PA in the same transmitter configuration.

Keywords

power amplifiers; LDMOS power amplifier; VDD-drive; envelope elimination-and- restoration system; envelope tracking technique; frequency 1 GHz; power 0.5 W; supply voltage modulation; DC-DC power converters; Delay; Envelope detectors; Linearity; Power amplifiers; Power system restoration; Predistortion; Radio transmitters; Radiofrequency amplifiers; Voltage; LDMOS; Predistortion; linearity; power amplifier;

fLanguage

English

Publisher

ieee

Conference_Titel

Norchip, 2007

Conference_Location

Aalborg

Print_ISBN

978-1-4244-1516-8

Electronic_ISBN

978-1-4244-1517-5

Type

conf

DOI

10.1109/NORCHP.2007.4481031

Filename

4481031