What mechanisms ensure effective electromagnetic interference (EMI) protection in shielded cable designs?

Q: What mechanisms ensure effective electromagnetic interference (EMI) protection in shielded cable designs?

A: Shielded cables employ multi-layered defense systems to mitigate EMI, starting with conductive barriers that reflect or absorb interfering signals. Metallic foils (typically aluminum or copper) create a continuous low-resistance path, while braided conductors—with coverage densities exceeding 85%—enhance flexibility while maintaining shielding integrity. For extreme environments, dual-shield configurations (foil + braid) achieve attenuation levels up to 100 dB at high frequencies.

Grounding systems are critical to performance: proper termination through 360° contact connectors ensures interference currents are safely diverted to earth. Additionally, dielectric materials like FEP or PTFE minimize signal leakage by maintaining consistent impedance, while drain wires provide alternative grounding paths in single-ended applications. These integrated design elements collectively prevent external EMI ingress and internal signal radiation, preserving data integrity in high-noise industrial and telecommunications environments.