Accurate synthesis of integrated RF passive components using surrogate models

Passive components play a key role on the design of RF CMOS integrated circuits. Their synthesis, however, is still an unsolved problem due to the lack of accurate analytical models that can replace the computationally expensive electromagnetic simulations (EM). Both, physical-based and surrogate models have been reported that fail to accurately model the complete design space of inductors. Surrogate-assisted optimization techniques, where coarse models are locally enhanced during the inductor synthesis process by using new EM-simulated points to update the model, have been proposed, but either the efficiency is dramatically decreased due to the online EM simulations or the optimization may converge to suboptimal regions. In this paper, we present a new surrogate model, valid in the entire design space with less than 1% error when compared with EM simulations. This model can be generated offline, and, when embedded within an optimization algorithm, allows the synthesis of integrated inductors with high accuracy and high efficiency, reducing the synthesis time in three orders of magnitude.