Thermal analysis and design of peripheral adaption power cell for power amplifier

Peripheral adaption power cell networks are designed to make the power cell open gradually with the increasing input power. The pre-determined emitter ballast resistors are used to perform the adaption operation. Power consumption then reduces especially for the center fingers with larger emitter ballast resistors. As a result, the novel power cell appears a reverse bell-alike temperature distribution different from traditional power cells. Finger spacing is further optimized to obtain a uniform temperature distribution which makes the distributed matching circuit more efficient. With this thermal design, the power amplifier shows an excellent output power of 33 dBm with PAE of 50%.