Design of a 3-volt HBT Power Amplifier for DCS

摘要

The design of an HBT power amplifier IC intended for 3-volt DCS applications is presented in this article. The impact on the isolation of transistor self-biasing under a large signal drive is investigated using SPICE, and a design improvement is made to eliminate the impact of transistor self-biasing on isolation. Excellent power and efficiency are obtained. For V_(cc) = 3.2 volts, a peak output power of 32.7 dBm is obtained with a peak efficiency of 50.6 percent. For a V_(cc) = 2.7 volts, a peak output power of 31.4 dBm is obtained with a peak efficiency of 51.3 percent. Small, innovative, cost effective packaging for the power amplifier is also described. The performance, size, and cost of this PA are all well suited for high volume cellular phone applications.