A key requirement within the modern mobile-handset power amplifier (PA) is a need to detect and control the transmitted power. This three-part article first explores the various methods of power control for amplifiers operating in both saturated and linear modes. The discussion continues with power detection techniques used in modern handsets. Topics include current, voltage, diode, power, logarithmic (log), and RMS detection, including performance characteristics such as RF bandwidth, video bandwidth, dynamic range, temperature compensation, and VSWR insensitivity.
This three-part series examines the subject as follows:
About the author
David S. Ripley
- Part 1: Power amplifier biasing for power control (click here)
- Part 2: Power detection methods (click here)
- Part 3: Power control feedback (click here)
received his B.S. degree in electrical engineering from Iowa State
University, Ames, in 1992 and the M.S EE degree from National Technical University
(NTU), Minneapolis, MN, in 2002. From 1992 to 1999, he worked in the Cellular
Subscriber Division, Motorola, Libertyville, IL, where he was involved in the design and
development of TDMA and AMPS handsets including RFIC design of receiver and
synthesizer functions. Since 1999, he has been with Skyworks Solutions, Inc. (previously
Conexant Systems, Inc.), Cedar Rapids, IA, where he has been involved with the design
of multiband HBT power amplifiers modules for the GSM and CDMA cellular handsets. He holds seven patents.