EMI/RFI Containment Solutions

RF Performance Considerations — Every cabinet, rack or enclosure has unique mechanical and RF containment requirements that need to be considered jointly to develop a solution to meet MIL-STD-461. Specifically, designs must consider the following:
  • Frequency Range of RF Attenuation. Typical solutions cover 10 kHz-18 GHz.

  • Degree of RF Attenuation. Typical need is for >40 dB; occasionally must have >60 dB for select frequencies.

  • Outer Panels, I/O Panels, Skins. RF Frequency & attenuation dB used to determine EMI/RFI gasket solution and mounting hole spacing/hardware selection.

  • Inlet/Exhaust Air Filters. RF Frequency & attenuation dB used to determine honeycomb aperture size and down-slope angle. Cooling airflow need determines overall filter size. Drip proof requirement determines need for down-slope honeycomb or external louvers.

  • Doors. In addition to RF Frequency & attenuation dB , high traffic open/close requires EMI/RFI gasket to be extremely durable. Door latch selection is critical to contain RF energy.

RF Containment:  Electromet Advantage — Electromet makes managing RF containment for cabinets, racks and enclosures easy!
  • Decades of experience seamlessly integrating mechanical & RF containment solutions. We manage it all in-house: design, manufacturing and testing.

  • Optimized RF containment performance without over-engineering the solution. EMI/RFI gaskets & filters are some of the most expensive components in a shielded cabinet, rack or enclosure. We optimize performance while minimizing cost.

  • Mature relationships with suppliers of EMI/RFI gaskets and honeycomb air filters provides competitive pricing and accurate lead-times and ensures optimal selection of suitable, cost-effective components.

  • Close partnerships with independent RF testing laboratories (such as Washington Laboratories in Frederick, MD) ensures independent performance validation, reliable test procedures and feedback and design collaboration for unique RF requirements.

  • Electromet cabinet designs include numerous mechanical features which enhance RF containment beyond EMI/RFI gaskets or honeycomb filters (extrusion design and assembly geometry, door latch selection, assembly hardware spacing).


RF Performance Considerations


Electromet Advantage - RF Performance
Validated — RF Shielding Requirement:
  • >40 dB attenuation in 1 MHz – 18 GHz range

  • Cabinet tested IAW IEEE Std 299-2006 (Table A); used modified procedure due to cabinet dimensions

  • Cabinet to provide TEMPEST barrier from cabinet to cabinet when used in conjunction with proper cabling, filtering, suitable electronic equipment and sealing of cabinet I/O panels

  • Table A: Test Frequencies
    (MHz)  1, 33.3, 65, 100, 130, 200, 260, 327, 415, 661, 830, 915
    (GHz)  1.29, 1.86, 2.1, 3.29, 4.19, 6.6, 8.4, 10.495, 13.22, 18

  • Shielding Effectiveness Test Results (below) validate >40 dB attenuation at all frequencies

RF Shielding Effectiveness — GKI 960 Style Cabinet
RF Shielding Effectiveness - GKI 960 Style Cabinet