An Accurate and Efficient Adaptive Interpolation Scheme for Complex Wideband Frequency Responses

An accurate and efficient adaptive interpolation scheme is proposed to estimate the wideband frequency responses with discontinuities in electromagnetic simulations. To avoid the Runge phenomenon and large errors due to discontinuities, the sampling points are carefully divided into several groups. Then, different interpolation strategies are used within and between groups. An iterative procedure is adopted to gradually refine the sampling points based on the local error estimate until the predefined accuracy criterion is satisfied. Two numerical examples are carried out to validate its performance. Results show that the proposed scheme can accurately and efficiently predict the wide band responses with many discontinuities, and is more efficient than the model order reduction (MOR) method.