Contrary to traditional analysis flows as expensive FEM simulation tools or inaccurate electrical models extractors, we developed MemsCompiler that implements a new real synthesis approach for RF MEMS. The new flow starts from system designer requirements and generates, in a one-click operation, a ready-to-fabricate layout (GDSII) and a passive fitted equivalent Spice circuit.
Concerning the circuit, physical considerations give us an equivalent schematic in which circuit parameters values must be adjusted to fit the required performances. As to the GDSII, which constitutes the main contribution of this work, Design Of Experiment technique, used in the first version of the synthesizer, gave about 11% of dispersion and found to be unsatisfactory in some cases. A more accurate modeling was indispensable.
Thus, we developed a neural networks-based modeling for circular inductors, which are considered by designers among the most stubborn components. This new modeling has shown to be very accurate: MemsCompiler produced about 3% of dispersion compared to the equivalent circuit and about 6% of dispersion for generated geometries. This modeling is flexible and could be rapidly generalized to other components.
RF-MEMS Compiler uses a component synthesis approach instead of the more traditional analysis approach. It starts from system designer requirements and creates, in a one-click operation, a ready-to-fabricate layout and a passive equivalent SPICE circuit (when relevant). This methodology shortcuts the trial and error procedure which is long, difficult, and offers no guarantee of obtaining the targeted performances. Furthermore, no single designer typically has the skills needed to effectively carry out these tasks. As demonstrated in the case of inductors, the approach can be easily generalized to any RF-MEMS component fabricated through a predefined process. First results are very promising. The inductor compiler lost no more than 5% accuracy compared to the equivalent circuit and produced no more than 11% dispersion of the generated geometry.
Reducing design cycle time is a main concern of CAD tools. MEMS designers particularly suffer from a long and difficult design procedure in which different phases are involved: solid modeling, meshing and simulation. In this paper, we present, MEMS Max, the new MEMSCAP environment fully oriented towards RF-MEMS designers. It brings to the designer flexible, complete and easy-to-use RF MEMS-oriented tools. At the same time, it reduces efficiently the design cycle time.