High-efficiency outphasing transmitter using class-E power amplifiers and asymmetric combining

✍ Scribed by Ramon Beltran; Frederick H. Raab; Arturo Velazquez

• Book ID: 102949464
• Publisher: John Wiley and Sons
• Year: 2009
• Tongue: English
• Weight: 520 KB
• Volume: 51
• Category: Article
• ISSN: 0895-2477
• DOI: 10.1002/mop.24758

✦ Synopsis

Abstract

Chireix outphasing systems have been used successfully with power amplifiers (PAs) operating in class‐B and F. Class‐E PAs can produce high efficiency at microwave frequencies. However, the impedances produced by conventional outphasing are unsuitable for class E, resulting in poor efficiency and/or poor dynamic range. The asymmetric combining technique described here uses transmission lines or equivalent networks of different electrical lengths to position the impedance loci to provide good dynamic range while maintaining high efficiency. This in turn allows linear power amplification of amplitude‐modulated signals with high average efficiency. The concept is verified by a 25.7‐W peak output power transmitter that achieves an efficiency of 85% or better over an amplitude range of 10 dB. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2959–2963, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24758