0.35‐μm SiGe BiCMOS variable‐gain power amplifier for WiMAX transmitters

Abstract

A 0.35‐μm SiGe BiCMOS variable‐gain power amplifier for WiMAX transmitters is presented. A voltage‐controlled variable resistor is used to control the gain of the linear amplifier. An open‐collector adaptive bias is utilized to obtain high linearity and efficiency. The measured power amplifier achieves a power gain of 22.2 dB, an output power of 20.6 dBm, and a power‐added efficiency of 24.4% with 10‐dB tuning range of linear gain. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2750–2753, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22851