How to avoid mutual interference between the two network ports of an edge computing box?

Simultaneous data transmission and reception via dual network ports on an edge computing box may cause mutual interference through spatial coupling or shared power ground loops, leading to a decrease in throughput. Isolation measures include:

1. Using an independent transformer and adding a common-mode filter CMZ2012A-900T to each network port (CM common-mode Z impedance 2012, size 2.0×1.2mm, 900T impedance 90Ω, 100MHz);

2. Using separate ferrite beads PBZ1608E600Z0T for the PHY power supplies of the two network ports;

3. PCB layout ensuring a distance of >15mm between the two network ports and preventing them from sharing the same reference layer gap;

4. Connecting the center tap of the network port transformer to their respective signal grounds via different capacitors or a single-point connection;

5. Shielded twisted-pair cable with both ends grounded.

Actual testing showed that a certain edge computing box with dual gigabit network ports under full load exhibited no degradation in bidirectional current radiated emission, achieving a throughput of 950Mbps.