Shielded enclosures

Electronics shields

Figure 1 - Simple equipment diagram

Figure 2 - Equivalent circuit related to the impedance coupling

Figure 3 - Topological diagram joined to the simple equipment model

Figure 4 - Sketch of the electromagnetic plane wave sent toward an infinite
flat shielding

Figure 5 - Plane wave propagation involved in the flat shielding model

Figure 6 - Description of a coaxial cell applied to attenuation measurements
provided by flat shielding samples

Figure 7 - TEM cell configured to measure the attenuation of a flat shielding
closing a cavity

Figure 8 - Dimensional parameters of a shielded enclosure exposed to electromagnetic
interferences…

Figure 9 - Attenuations AE and AH of a spherical
metal shell with electrical conductivity σm &#61; 107S/m, radius R &#61; 1m and thickness e &#61; 0.25mm

Figure 10 - Return paths of odd-mode currents entering in low-pass filter inserted
in power supply line

Figure 11 - Parameters involved in Zt transfer impedance concept

Figure 13 - Equivalent circuit diagram leading to computation of the resulting
voltage VA at shielded cable end

Figure 14 - Sketched diagram of screen factor measurement principle

Figure 15 - Path of IB current passing
in unshielded connector

Figure 16 - Collected and diverted IB current on connector shells

Figure 17 - Transfer impedance simulations of unshielded and shielded connectors

Figure 18 - Current paths IB without
connector

Figure 19 - Topological configuration with use of arrestors

Figure 20 - – Placement of ferrite rings (8b) to damps resonances on outer face
of shielded cables