De-embedding Technique for Extraction and Analysis of Insulator Properties in Cables

This work utilizes the Nicolson-Ross-Weir (NRW) method to analyze the frequency-dependent material properties of the insulator inside cables. These properties include ε(f), μ(f), and tanδ. Common methods for this analysis include the open-ended coaxial probe method, free space method, resonant method, and transmission/reflection line method. Each method has a suitable structure and may require additional samples for measurement. Our proposed method can calculate the real material properties of the insulation after foaming in the cable following extrusion, up to 40 GHz. This study also compiles the effects of various factors on the extraction of material parameters and provides a detailed analysis of potential sources of error. We observed that variations in production can introduce discrepancies after de-embedding, which can result in anomalies at the dissipation factor curve. Finally, we propose a correction method that effectively improves the accuracy of the extracted dielectric constant.