Fast Frequency Sweep for Building-Block Connections in Microwave Filter Analysis via the Reduced-Basis Method

Abstract

Current design of microwave filters relies on intensive computer simulations to accurately predict the electromagnetic behavior of microwave circuits. Typically, global optimization techniques are taken into account and reduced knowledge of the actual electromagnetics is considered within computer-aided design. To this end, microwave filter development results in a rather time-consuming engineering task.In this work, we address a methodology for fast frequency analysis in microwave circuits in order to speed up full-wave simulations. Appropriate Finite Element solution to time-harmonic Maxwell's equations in the frequency band of interest is involved and a reliable reduced-order model is obtained via the ReducedBasis Method. This time, the analysis domain is decomposed into building-blocks and a reduced-order model for fast frequency sweep is carried out for each block. The electromagnetics within each block is described in terms of a Generalised Impedance Matrix (GIM) transfer function. In order to get the frequency response of the whole microwave circuit, the GIMs for each block should be connected appropriately. This process has been traditionally done frequency by frequency and can be considered a bottleneck in Domain Decomposition (DD) approaches. In this work, we take into account a further fast frequency sweep for the building-block connection problem. As a result, a speed-up in the simulation time in microwave circuits is achieved as the bottleneck in the DD approach is completely removed.