Podsiadlik, Tomasz and Dooley, John and Farrell, Ronan (2012) Improved Coding-Efficiency Two-Level Source Encoder for RF Switch-Mode Power Amplifiers. IEEE Transactions on Circuits and Systems II: Express Briefs, 59 (10). pp. 618-622. ISSN 1549-7747

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Abstract

A ΣΔ-driven RF switch-mode power amplifier is inherently linear only when it has a two-level output. At the same time, a two-level output generates the largest amount of quantization noise. This brief analyzes the effect of nonequal level spacing in a three-level ΣΔ output and provides a method for shaping the corresponding error noise to regions outside the band of interest. Subsequently, the nonlinearity-shaping property is utilized to obtain an improved two-level drive signal based on three-levelΣΔmodulation. The new binary drive signal is proven to have better adjacent channel leakage ratio and higher coding efficiency than a conventional two-level ΣΔ modulator. In the investigated case, measured coding efficiency improves from 8.9% of the conventional two-level modulator to 21% of the modified two-level modulator.

Item Type:	Article
Keywords:	Coding efficiency; sigma delta; switch-mode power amplifier; (SMPA);
Academic Unit:	Faculty of Science and Engineering > Electronic Engineering
Item ID:	4299
Depositing User:	Ronan Farrell
Date Deposited:	09 Apr 2013 14:25
Journal or Publication Title:	IEEE Transactions on Circuits and Systems II: Express Briefs
Publisher:	Institute of Electrical and Electronics Engineers
Refereed:	Yes
URI:	Publisher
Use Licence:	This item is available under a Creative Commons Attribution Non Commercial Share Alike Licence (CC BY-NC-SA). Details of this licence are available here

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