The first completely physical electro-thermal model is presented that is capable of
describing the large signal performance of MESFET- and HEMT-based, high power
microwave and millimeter wave monolithic and hybrid ICs, on timescales suitable for
CAD. The model includes the effects of self-heating and mutual thermal interaction
on active device performance with full treatment of all thermal non linearities. The
electrical description is provided by the rapid quasi-2D Leeds Physical Model and the
steady-state global thermal description is provided by a highly accurate and computationally
inexpensive analytical thermal resistance matrix approach. The order of
the global thermal resistance matrix describing 3-dimensional heat flow in complex
systems, is shown to be determined purely by the number of active device elements, not
the level of internal device structure. Thermal updates in the necessarily iterative, fully
coupled electro-thermal solution, therefore reduce to small matrix multiplications
implying orders of magnitude speed-up compared to the use of full numerical thermal
solutions capable of comparable levels of detail and accuracy.
Electro-thermal Modelling of Monolithic and Hybrid
Microwave and Millimeter Wave IC's
