Coaxial cables are electrical cables widely used in legacy networks across industries, including telecommunications, broadcasting, and data center networks, to transfer high-frequency signals from source to destination. Electromagnetic interference (EMI) can significantly impact the performance of coaxial cables because of the clashing electromagnetic signals from nearby devices. All of this may lead to signal attenuation and network failure. This post shares helpful pointers on mitigating EMI in coaxial cables and facilitate smooth functioning of networks.
Useful Pointers for EMI Mitigation in Coaxial Cables
While shielding is an effective option to suppress electromagnetic interference, there are some factors to consider when installing and arranging the network to curb EMI in coaxial cables. Here are some pointers that may be useful in mitigating EMI in coaxial cables and achieving seamless data connectivity in networks.
- Grounding: Some EMI may be present in the conductive wires of the cable. Hence, the sheath must be grounded to the back shell of the connector This allows such signals to escape without disturbing the network. Connecting the shield to a low-impedance ground point is essential to divert unwanted currents and minimize potential differences.
- Cable Routing: To minimize electromagnetic coupling, the coaxial cables must be separated from power cables. In a network, these cables must be routed so that they do not cross paths with high-frequency signal carriers.
- Use of Shielded Cables: Choose coaxial cables with adequate shielding, especially braided or with foil shields to protect against external electromagnetic fields. The shield must be properly terminated at both ends to maintain its effectiveness and ensure EMI suppression.
- Cable Length: Choose the cables as per the frequency range you require in the network, the amount of data sent, and the geographical distance of the network. Keep appropriate cable lengths as per the distance and not too long to reduce signal attenuation and susceptibility to EMI.
- Ferrite Chokes: Add ferrite chokes or beads around coaxial cables near their connectors to suppress high-frequency noise and EMI. They act as passive filters and absorb unwanted EMI signals.
- Shield Integrity: Ensure the cable shield is intact and properly connected to the connector. Also, ensure the shield is continuous throughout the cable and has no cracks or other damages.
- Connected Devices: Connected wireless devices in the network as well as nearby ones, lights, and any other machinery may also produce EMI and hamper the performance of coaxial cables.
- Signal Filtering and Conditioning: Employ inline filters or signal conditioners to mitigate specific frequencies of EMI that may affect coaxial cable signals. These filters block unwanted EMI.
- Testing and Compliance: While visual inspection of the cable and connected devices is necessary, you can also consider using EMI detectors and spectrum analyzers to find the presence of EMI. Ensure coaxial cable installations comply with relevant industry standards and regulations regarding EMI mitigation. These include standards such as FCC Part 15 for electromagnetic compatibility (EMC).
Effectively mitigating electromagnetic interference in coaxial cables is essential for maintaining reliable signal transmission and minimizing performance issues. By implementing appropriate EMI mitigation solutions, such as shielding, cans, or ferrite chokes, you can enhance the performance and longevity of your coaxial cable networks and to some extent protect other devices from such EMI. While mitigating EMI from coaxial cables is important, the entire network with all its devices up to the PCB level must be prevented from EMI. Hence, board-level EMI shielding is also necessary. This can be achieved through effective PCB EMI shielding, comprising a combination of grounding techniques, use of thin and lightweight EMI shields, and more. XGR Technologies offers SnapShot® EMI shields made from a thin polyetherimide film on the interior and conductive tin on the exterior surfaces. These flexible and lightweight shields can be easily used on any type of PCBs to mitigate electromagnetic inference across network applications. If you need further information on SnapShotTM EMI shields and their effectiveness in shielding EMI in PCBs, you can contact the team at XGR Technologies via phone or email.
