Radio-frequency interference mitigation strategies for high-speed connectors

Radio-frequency interference (RFI) issue becomes more and more significant in recent high-speed and small-form-factor electronic systems. Especially when their RF antennas cannot put away from digital input/output (I/O) interfaces, the coupling noise could highly degrade the antenna and system performance. In this problem, the amount of differential-mode noise is usually much larger than the common-mode one. For reducing the differential-mode noise, two useful mitigation strategies are suggested. These strategies are also workable for reducing the common-mode noise. For demonstration, a specific scenario of Wi-Fi dongle and its interface is defined and studied. Good mitigation results are indeed obtained for both common-and differential-mode cases by these strategies.