Deriving a power amplifier linearizer from a physics-based system-level model

✍ Scribed by Telmo R. Cunha; Eduardo G. Lima; Hugo M. Teixeira; Pedro M. Cabral; José C. Pedro

• Publisher: John Wiley and Sons
• Year: 2010
• Tongue: English
• Weight: 795 KB
• Volume: 20
• Category: Article
• ISSN: 1096-4290
• DOI: 10.1002/mmce.20436

✦ Synopsis

The RF power amplifier (PA) is a nonlinear system with an intrinsic and dynamic feedback mechanism. The application of an adequate linearizer (which is also a nonlinear dynamic system) inserted at the input of the signal path (i.e., predistortion) is very important to maintain a linear transmission chain when the PA carries high power signals (avoiding spectral regrowth). This article presents a new PA linearizer model whose topology has support on the physical behavior of the general PA electronic circuit. As the proposed model is of a feed-forward nature, it is suited for implementation on digital hardware devices, such as field programmable gate array and digital signal processor. Validation tests were performed on the linearization of a 900 MHz PA excited with WCDMA-3GPP signals. Comparison with other state-of-the-art linearizer models is included, demonstrating very good linearization results. Moreover, this model has potential to be an adequate linearizer for a wider range of applications since it has physical support. V