A Novel Compact Dual-Functional Circuit With Differential-Mode Equalization and Broadband Common-Mode Suppression Using Patterned Ground Plane

• Published in: IEEE transactions on components, packaging, and manufacturing technology (2011) Vol. 14; no. 2; pp. 300 - 308
• Main Authors: Chen, Yu-Ren, Lin, Yi-Ting, Wu, Tzong-Lin
• Format: Journal Article
• Language: English
• Published: Piscataway IEEE 01.02.2024; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Broadband; Broadband common-mode (CM) suppression; Circuit boards; common-mode filter (CMF); Equalization; Equalizers; Equivalent circuits; Frequency domain analysis; Ground plane; Intersymbol interference; intersymbol interference (ISI); passive differential equalizer; patterned ground structure (PGS); Printed circuits; Resonant frequencies; Signal integrity; Time domain analysis
• ISSN: 2156-3950; 2156-3985
• DOI: 10.1109/TCPMT.2024.3350553

A new passive differential-mode equalizer (DME) equipped with the function of common-mode (CM) suppression is proposed by using differential shunt stubs (DSSs) and patterned ground structure (PGS). The DSS is mainly responsible for generating the high-pass response in differential mode to achieve the equalization effect with a data rate of up to 10 Gbps, while the PGS is responsible for creating the wideband CM suppression from 2 GHz to more than 10 GHz. The equivalent circuit model is constructed and the frequency-domain analysis is applied to calculate the even-mode and odd-mode responses. The calculated responses are validated and then used to solve the approximated resonant frequencies and cut-off frequency of the CM response analytically. Additionally, time-domain eye simulation, full-wave simulation, and measurement are performed to verify the effectiveness of differential-mode equalization and wideband CM suppression. Most crucially, this proposed circuit not only provides better performance on signal integrity, but also features the most compact size in a 2-layer printed circuit board (PCB) and the lowest frequency 2.1 GHz of the CM stopband, in contrast to the previous works.