An Efficient Approach to Find the Truncation Frequency for Transmission Line-Based Dielectric Material Property Extraction


Material properties of dielectric substrates play an important role in high-speed printed circuit board (PCB) design. The Transmission Line-Based material property extraction method is an effective way to obtain substrate properties. However, the method requires transmission line dominated S-parameter data. Even with de-embedding, S-parameters may include non-transmission line effects. Thus, to obtain correct material properties, it is necessary to truncate the S-parameter data at a frequency before non-transmission line effects begin to dominate. In this paper, a novel binary fitting-based method is proposed to find the truncation frequency accurately and efficiently. By using a binary search algorithm and physics-based fitting method, the proposed method is able to find the truncation frequency in only a few iterations. This method has been validated for hundreds of real measurement cases and has shown good adaptability and rationality.

Meeting Name

2018 IEEE Symposium on Electromagnetic Compatibility, Signal Integrity and Power Integrity, EMC, SI and PI 2018 (2018: Jul. 30-Aug. 3, Long Beach, CA)


Electrical and Computer Engineering


This work was supported in part by the National Natural Science Foundation of China under Grant 61771425.

Keywords and Phrases

Busbars; Dielectric materials; Electric lines; Electromagnetic compatibility; Printed circuit boards; Printed circuit design; Scattering parameters; Substrates; 'Root-Omega' method; Binary fitting; Binary search algorithm; Dielectric substrates; Printed circuit board designs; Property extractions; Substrate properties; Truncation frequency; Extraction; Material property extraction; Transmission-line based

International Standard Book Number (ISBN)


Document Type

Article - Conference proceedings

Document Version


File Type





© 2018 Institute of Electrical and Electronics Engineers (IEEE), All rights reserved.

Publication Date

01 Jul 2018