Equipping high speed interfaces can also lead to reception sensitivity deterioration.
As Wi-Fi communication becomes faster, the speed of internal data transmission interfaces will also increase, and frequencies that will interfere with Wi-Fi signals will also be processed.
For this reason, PCI Express signals are radiated and the 2.4 GHz band Wi-Fi reception sensitivity deteriorates.
Also, due to the popularity of USB Type-C connectors, support for USB 3.1 has progressed, and due to the USB 3.1 having a signal frequency close to the 2.4 GHz band, there are examples that lead to Wi-Fi reception sensitivity deterioration.
A noise filter is to be inserted on the interface signal line to eliminate noise that interferes with Wi-Fi from high speed interfaces.
However, since these interfaces use high speed signals, you are required to select those that do not affect signal waveforms.
In principle, common mode choke coils/common mode noise filters (CMCC) do not affect differential signals, but since there are differential mode impedances in actual products to some extent, you are required to select applicable parts.
Examples of Radiation Noise from High Speed Interfaces