Concurrent Multi-Band Envelope Modulated Power Amplifier Linearized Using Extended Phase-Aligned DPD

Author

Kwan, A.K. ; Younes, M. ; Ghannouchi, F.M. ; Silong Zhang ; Wenhua Chen ; Darraji, R. ; Helaoui, M. ; Hammi, O.

Author_Institution

Schulich Sch. of Eng., Dept. of Electr. & Comput. Eng., iRadio Lab., Univ. of Calgary, Calgary, AB, Canada

Volume

62

Issue

12

fYear

2014

fDate

Dec. 2014

Firstpage

3298

Lastpage

3308

Abstract

This paper reports an envelope tracking (ET) transmitter architecture for multi-band/widely-spaced carrier signals. Due to the bandwidth limitations of the envelope modulator, the dynamic supply voltage is controlled by combining the low frequency envelopes of the multi-inputs rather than the true composite envelope of the input signals. The ET transmitter is tested for dual-band and tri-band power amplifiers (PAs) operating in concurrent mode using various bandwidth carrier aggregated long term evolution (LTE) signals. The transmitter is linearized using a phase-aligned Volterra digital predistortion that considers the inter-modulation distortion (IMD) products around the carrier frequencies as well as the third-order IMD products in the tri-band case. Experimental results are shown to validate the proposed techniques for linearization and efficiency enhancement of the multi-band ET transmitter and compared to the case of fixed supply biasing of the PA.

Keywords

Long Term Evolution; Volterra equations; linearisation techniques; modulators; power amplifiers; LTE signal; bandwidth carrier aggregated long term evolution signal; bandwidth limitation; carrier frequency; concurrent multiband envelope modulated power amplifier; dual-band PA; dual-band power amplifier; dynamic supply voltage; envelope modulator; envelope tracking transmitter architecture; extended phase-aligned DPD; input signal composite envelope; intermodulation distortion; linearization technique; low frequency envelope; multiband ET transmitter enhancement; multiband/widely-spaced carrier signal; phase-aligned Volterra digital predistortion; third-order IMD product; triband PA; triband power amplifier; Bandwidth; Baseband; Dual band; Frequency modulation; Predistortion; Transmitters; Concurrent mode; digital predistortion (DPD); envelope tracking (ET); long term evolution (LTE)-advanced carrier aggregation; power amplifier (PA);

fLanguage

English

Journal_Title

Microwave Theory and Techniques, IEEE Transactions on

Publisher

ieee

ISSN

0018-9480

Type

jour

DOI

10.1109/TMTT.2014.2365816

Filename

6957597