EMC Test Facilities

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EMC Test Facilities

Radio Frequency Shielded Enclosures

Our EMC compliance testing facilities include several RF shielded enclosure formats that are suitable for a broad range of EMC compliance testing procedures.

An RF shielded enclosure is a room that provides an environment shielded against external ambient RF emissions (FM, AM radio, TV, cell phone etc). The RF shielding will also prevent RF signals generated within the enclosure from interfering with these same licensed RF signals.

A fully anechoic RF shielded enclosure has RF absorbing material applied to all walls, ceiling and floor and is free from RF reflections. Fully anechoic RF shielded enclosures are ideal for radiated RF emission measurements on radio transmitters, radiated RF immunity measurements in accordance with IEC 61000-4-3 and pre-compliance EMC emission measurements to CISPR 32.

A semi-anechoic RF shielded enclosure is similar to a fully anechoic RF shielded enclosure, with the exception that no RF absorber material is applied to the floor. These enclosures can be used for measurements where a reflection off the floor will not impact on the EMC measurement as well as radiated RF emission measurements requiring the reflection to be included as part of the measurement (eg Radiated RF emission measurements in accordance with CISPR 32 and FCC part 15).

A bare, or unlined RF shielded enclosure that has no RF absorbing material applied to its internal surfaces is generally not suitable for EMC measurements involving radiated RF signals. These enclosures are still ideal for conducted emission and conducted immunity measurements, where the signal is either measured or applied directly to a device via a coupling network (LISN, CDN etc).

EMC Test Facilities
EMC Test Facilities

Indoor Anechoic Open Test Site (iOATS)

Our Indoor Open Area Test Site simulates an outdoor Open Area Test Site, without the hassle of driving to a remote location, away from RF ambient interference (TV, AM/FM Radio, Cell phone etc) that is common around developed locations.
The iOATS is fitted with both a 1.2 m x 2.2 m wide personnel/equipment access door and a 3m x 3m vehicle access door. An engine exhaust extraction system has also been installed.

A dedicated turntable is used to rotate small test samples, while a mast (located 3m away) controls the height (1-4 m) and polarisation of the measuring antenna.

The test operator, EMC receiver and ancillary equipment for the equipment under test, are conveniently located outside the enclosure.

Fully Anechoic RF Shielded Enclosure

A fully-anechoic RF shielded enclosure is utilised for measurements of radiated RF power in accordance with CISPR 14. This enclosure is also ideal for radiated RF immunity measurements in accordance with IEC 61000-4-3.

This fully-anechoic RF shielded enclosure is ideal for pre-compliance radiated RF emission measurements, as there are no reflections off the floor and the height of the antenna does not need to be altered in comparison to an Open Area Test Site.

EMC Test Facilities
EMC Test Facilities

CISPR 25/MIL-STD-461 RF Shielded Enclosure

Both CISPR 25 and MIL-STD 461 standards specify radiated emission measurements to be performed inside an ALSE (Absorber Lined Shielded Enclosure). ALSE is defined as shielded enclosure/screened room with radio frequency-absorbing material on its internal ceiling and walls.

ALSE requirements are defined as follows:

To minimise reflected energy during radiated emission measurements it is necessary to apply RF absorbing material to the walls and ceiling of the shielded enclosure.

No absorber material shall be placed on the floor for vehicle or component level tests. The following ALSE requirements shall also be met for performing radiated RF emissions measurements.

  • Performance of the absorption material shall be greater than or equal to 6 dB in the 70 MHz to 2500 MHz frequency range.
  • For radiated emissions tests, the shielded enclosure shall be of sufficient size to ensure that neither the vehicle/EUT nor the test antenna shall be closer than 1 m from the walls or ceiling, or to the nearest surface of the absorber material used thereon.
  • For radiated emissions measurements in particular, the ALSE shall be cleared of all items not pertinent to the tests. This is required in order to reduce any effect they may have on the measurement. Included are unnecessary equipment, cable racks, storage cabinets, desks, chairs, etc. Personnel not actively involved in the test shall be excluded from the ALSE.

Electronic products used in automotive industry are tested according to CISPR 25. It is also referred by UN ECE Regulation 10 and ISO 11452-2 standards. CISPR 25 chamber is a RF-shielded semi-anechoic chamber providing an ideal environment for compliant CISPR 25 testing.

An RF shielded enclosure (without any RF absorber material) has been configured specifically for measurements of immunity to: Conducted RF, Transients, Surges & ESD in accordance with commercial and automotive standards. This enclosure is also linked via a penetration to the fully anechoic enclosure and can also be utilised as a control room for monitoring and exercise equipment.

EMC Test Facilities