Transfer function order reducing method for successive network reduction in complex frequency space

In this paper we present a direct computational method for calculating thermal transfer impedances between two separate locations of a given physical structure aimed at the implementation into a field-solver based on the SUNRED (SUccessive Node REDuction) algorithm. The paper describes a further reduction method in complex frequency space based on Hankel singular values. We tested the method on a typical MCPCB assembled LED structure in 2D. With that model we were able to comparise the results from analytical calculations and from that approximations. The results show that the approximation method is very accurate, the calculated error were below 2 %.