Power detection and control for mobile handsets, (Part 1 of 3): Power amplifier biasing for power control
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:
- Part 1: Power amplifier biasing for power control
- Part 2: Power detection methods
- Part 3: Power control feedback