At IMS 2011 in Baltimore, Computer Simulation Technology (CST) announced the introduction of a finite element based Eigenmode solver in CST MICROWAVE STUDIO® version 2011 SP3.

The computation of Eigenmodes is essential for the accurate design of resonant structures, such as cavities, filters or particle accelerators. Typical results of these simulations are resonance frequencies and Q-values. An additional application area of Eigenmode solvers is the design of periodic devices, such as slow-wave structures (e.g. travelling wave tubes) and metamaterials, where phase-diagrams can be derived from unit cells.

One of the main challenges in the design of cavity resonators is the precise representation of the simulation model’s actual geometry. This is required for the computation of eigenfrequencies, as well as the calculation of surface currents, which are necessary to evaluate the losses in the cavity. Alongside the Finite Integration Technique (FIT) based eigenmode solver, CST MICROWAVE STUDIO(CST MWS) version 2011 now features an alternative Eigenmode solver which uses the Finite Element Method (FEM). The new eigenmode solver features curved elements of arbitrary order, with which users of the general purpose CST MWS FEM frequency domain solver will already be familiar. These elements enable a conformal representation of the geometry which improves the simulation accuracy. In combination with the unstructured FEM grid, which can resolve small structure details very efficiently, it can increase the simulation performance dramatically.

“Eigenmode computation has a long tradition in CST, and we are proud to present this exciting new solver to our long standing customer base,” stated Peter Thoma, Managing Director, R&D, CST. “The introduction of curved elements, in combination with the accuracy enhancing True Geometry Approximation, represented a major technological step forward for the CST MWS FEM frequency domain solver. The performance increase through curved element FEM applied to eigenmode calculation is extraordinary in our test cases.”

The new CST MWS eigenmode solver is released with service pack 3 of CST MICROWAVE STUDIO 2011. It is now available for download to customers with valid maintenance contract for the eigenmode solver.