A Novel ACA for Analyzing Electromagnetic Field Problems of Filter with Waveports

In this paper, a fast direct method based on adaptive cross approximation (ACA) is used to calculate the electromagnetic field of the waveport which is a difficulty when analyzing metal-dielectric filter models. Different from the traditional method of moments (MoM), the system matrix is divided into blocks and then compressed in this method which greatly improves the calculation efficiency while ensuring the calculation accuracy. Numerical results are presented to demonstrate that the proposed ACA can efficiently and accurately calculate the metal-dielectric filter models.