Electro-thermal modelling of monolithic and hybrid microwave and millimeter wave IC's

The first completely physical electro-thermal model is presented that is ca pable of describing the large signal performance of MESFET- and HEMT-based, high power microwave and millimeter wave monolithic and hybrid ICs, on tim escales suitable for CAD. The model includes the effects of self-heating an d mutual thermal interaction on active device performance with full treatme nt of all thermal non linearities. The electrical description is provided b y the rapid quasi-2D Leeds Physical Model and the steady-state global therm al description is provided by a highly accurate and computationally inexpen sive analytical thermal resistance matrix approach. The order of the global thermal resistance matrix describing S-dimensional heat flow in complex sy stems, is shown to be determined purely by the number of active device elem ents, not the level of internal device structure. Thermal updates in the ne cessarily iterative, fully coupled electro-thermal solution, therefore redu ce to small matrix multiplications implying orders of magnitude speed-up co mpared to the use of full numerical thermal solutions capable of comparable levels of detail and accuracy.