Asynchronous modulator for linearization and switch-mode RF power amplifier applications

Author

Johnson, T. ; Mekechuk, K. ; Kelly, D. ; Lu, J.

Author_Institution

PWRF Inc., Austin, TX, USA

fYear

2009

fDate

7-9 June 2009

Firstpage

185

Lastpage

188

Abstract

An implementation of an asynchronous modulator which encodes a modulated RF signal into a two level pulse train is described. The modulator is designed for RF switch mode amplifier applications and feedback linearization using conventional linear power amplifiers. The modulator is implemented in 0.18 mum SiGe BiCMOS and operates over a frequency range from 750 MHz to 2.2 GHz. The design includes the implementation of a fourth order complex bandpass filter and an encoder to synthesize a binary pulse train with asynchronous zero crossings. Experimental results are shown for a power amplifier module where the modulator is configured in a feedback loop linearizing a Doherty power amplifier while processing a three carrier WCDMA input signal.

Keywords

BiCMOS integrated circuits; Ge-Si alloys; UHF integrated circuits; UHF power amplifiers; modulators; BiCMOS; Doherty power amplifier; SiGe; WCDMA input signal; asynchronous modulator; asynchronous zero crossing; bandpass filter; binary level pulse train; feedback loop linearization; frequency 750 MHz to 2.2 GHz; level pulse train; linear power amplifier; size 0.18 mum; switch-mode RF power amplifier application; BiCMOS integrated circuits; Feedback; Germanium silicon alloys; Power amplifiers; Pulse amplifiers; Pulse modulation; Radio frequency; Radiofrequency amplifiers; Silicon germanium; Switches; feedback amplifiers; microwave power amplifiers; sigma-delta modulation; switching amplifiers;

fLanguage

English

Publisher

ieee

Conference_Titel

Radio Frequency Integrated Circuits Symposium, 2009. RFIC 2009. IEEE

Conference_Location

Boston, MA

ISSN

1529-2517

Print_ISBN

978-1-4244-3377-3

Electronic_ISBN

1529-2517

Type

conf

DOI

10.1109/RFIC.2009.5135518

Filename

5135518