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.
| Original language | English |
|---|---|
| Article number | 6957597 |
| Pages (from-to) | 3298-3308 |
| Number of pages | 11 |
| Journal | IEEE Transactions on Microwave Theory and Techniques |
| Volume | 62 |
| Issue number | 12 |
| DOIs | |
| State | Published - 1 Dec 2014 |
Bibliographical note
Publisher Copyright:© 1963-2012 IEEE.
Keywords
- Concurrent mode
- digital predistortion (DPD)
- envelope tracking (ET)
- long term evolution (LTE)-advanced carrier aggregation
- power amplifier (PA)
ASJC Scopus subject areas
- Radiation
- Condensed Matter Physics
- Electrical and Electronic Engineering