Measurement-Based Signal Integrity Analysis of Coupled Thin-Film Microstrip Lines

This paper explores the application of Thin-Film Micro-Strip Lines (TFMSLs) in high-frequency technologies, specifically within fifth-generation communication systems (5G), due to their compatibility with low-resistivity substrates. Various test structures comprising coupled TFMSLs with distinct geometric structures are examined to address critical scenarios such as matching, mismatching, and the presence of neighboring traces. This investigation focuses on signal integrity analysis and evaluates the effectiveness of TFMSL technology in such systems. Using the commercial simulator Keysight Advanced Design System (ADS), a frequency analysis is conducted to assess the impact of these geometries on mixed-mode S-parameters, with comparisons drawn to measurement results. Subsequently, time-domain analyses are performed using the measured single-ended S-parameters as input, evaluating high-speed digital links through eye-diagram metrics across a wide range of data-rate values (from 1 to 100 Gbit/s). Design maps for different TFMSL structures are generated, providing optimized trade-offs for the operating conditions required by the link (driver-line-receiver).