Design of a Wi-Fi-Compatible Common-Mode Noise Filter Using Dual-Band Matching Network

Modern digital signal transmission heavily relies on differential-mode signals. However, challenges such as asymmetrical routing, bending, and timing skew can compromise their symmetry, leading to common-mode noise issues. To address this challenge, we propose a dual-band absorptive common-mode noise suppression filter incorporating a series unified dual-band matching network. This approach effectively maintains the integrity of differential signals while suppressing common-mode noise. The proposed architecture has been verified to achieve an absorption efficiency of over 80% in the target frequency bands of 2.4-2.48 GHz and 5.18-5.32 GHz. They are furthermore, adding the dual-band matching network results in only a slight increase in the overall footprint. This implementation presents a promising solution for mitigating electromagnetic interference (EMI) challenges in digital signal transmission.