“To shield or to absorb?”: 9h30 9th March 2022 - Plenary Session

Summary form only given, as follows. The complete presentation was not made available for publication as part of the conference proceedings. Modern equipment is nearly always shielded and is using higher frequencies, thus smaller wavelengths. If the wavelength becomes smaller than the dimensions of a shielded enclosure, the fields will resonate which creates large amplitude variation inside the shielded enclosures, resulting in a drastic decrease of the shielded effectiveness. Any practical shielded enclosure needs a door, or a hatch, or a cap which is connected via screws, rivets, gaskets etc. The distance between any electrically connection shall be small that 1/100 of a wavelength, resulting in extremely short distances between screws, or very high requirements for gasket and compression. If we can decrease the field intensity inside the shielded enclosure, we can relax the strict requirements about those 1/100th short distances. Or even simple, we do not need a shielded enclosure anymore, but we need absorbers. Several examples of absorption compared to shielding will be shown. When to absorb and delete the shield: that's the question…