How do I design the cable entry panel for a shielded room to maintain the room's shielding effectiveness?

Designing the cable entry panel for a shielded room to maintain the room's shielding effectiveness requires that every cable penetrating the room's shield is filtered, shielded, or terminated at the penetration panel to prevent electromagnetic energy from leaking into (or out of) the room through the cable conductors. The cable entry panel (also called a penetration panel or filter panel) is a section of the shielded room wall containing: feedthrough connectors (for coaxial cables: bulkhead-mount RF connectors (SMA, N-type, BNC) that bond the cable shield to the room wall, maintaining the shielding continuity), feedthrough filters (for power, control, and data cables: pi-filter or C-filter feedthroughs that attenuate conducted EMI on each conductor while passing the desired signals; for AC power: filtered power entry modules with integral EMI filters (L-C-L or pi topology)), fiber optic feedthroughs (for high-speed data: fiber optic cables are inherently immune to EMI and do not degrade the room's shielding; the fiber penetration must be sealed against air leaks but: no electrical filtering is needed), and waveguide-beyond-cutoff tubes (for pneumatic lines, fluid lines, or cables that cannot be filtered: the cable passes through a metal tube whose diameter is small enough that it acts as a waveguide below cutoff at the frequencies of interest; the tube attenuates any electromagnetic energy traveling along it). The panel construction: the penetration panel is a thick metal plate (steel or aluminum, 3-6 mm thick) welded or bolted to the room wall with continuous conductive contact (no gaps). All feedthrough components are bonded to the panel with 360-degree contact.