When equipment may be too heavy, sensitive or cumbersome, the use of a temporary, flexible enclosure attached to an existing or assembled ground plane can provide shielding to meet test standards that need -85dB in shielding performance from 30 MHz to 18GHz depending on the enclosure’s construction and filter options. The highly conductive portable system can be moved to the EUT’s location when transportation is difficult or cost prohibitive.
An existing conductive floor, usually aluminum, can be used to fully isolate the EUT with the addition of flexible, temporary walls and provides cost savings over installing a separate, fully welded chamber. Where no suitable floor exists, for example a concrete floor, a steel plated or conductive fabric temporary floor can be installed and connected to the tent structure. Using a conductive floor is necessary to create a ground plane. If the floor is not fully conductive, RF will leak at the floor level.
Attaching the conductive enclosure’s walls to the floor can also be tailored to the needs of the EUT and the test environment including:
- Metal bars that clamp the conductive material to the conductive floor, or
- RF tight fabric fastener system to make the connections between the walls and the floor.
This approach allows the test enclosure to be structured to fit the EUT for size, maneuverability, shielding effectiveness, and permanence. An alternative method is panel construction which allows the tent to be attached to an internal frame and is often used for large enclosures. Where equipment cannot be moved, for example electronics racks, a flexible enclosure can be designed to fit over the rack with conductive fabric fastener system connecting the enclosure to a detachable floor.
Portable, temporary enclosures can eliminate the use of a door threshold for easy placement of EUT inside the test chamber. ITAR registered, Select Fabricators designs custom sized medium to large RF shielded chamber systems with or without attached floors and will lend their expertise in recommending the appropriate features to meet end use requirements.