Compact Modeling of Mutual Thermal Coupling for the Optimal Design of SiGe HBT Power Amplifiers

Most bipolar-transistor compact models incorporate some level of self-heating capability in order to determine the impact of thermal effects on circuit performance. Techniques for predicting mutual-thermal-coupling effects, however, are not readily available within most commercial CAD platforms. Presented in this brief is a technique which allows for the easy modification of design-kit-supplied models to predict and optimize mutual thermal coupling using commonly available CAD tools such as Cadence and Spectre.