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TEMPEST, SCIF, and Electronic Shielded Enclosures

For systems to be certified to TEMPEST (Telecommunications Electronics Material Protected from Emanating Spurious Transmissions) specific test standards need to be passed such as NSA No. 94-106 for shielded enclosures and other NSA standards depending on the intended environment and operation. The TEMPEST certified telecommunications electronic enclosure needs to be a “Faraday Cage”. A Faraday Cage is an enclosure made of electrically conductive materials capable of blocking magnetic and electric fields, commonly known as the electromagnetic field, see Figure #1.

Figure 1 Electric and Magnetic Field

Figure 1 – Electric and Magnetic Field
(courtesy of HyperPhysics)

Figure 2 Shielded Electronic Enclosures

Figure 2 – Shielded Electronic Enclosures
(courtesy of Milium Textiles and Vertex Structures)

Figure 3 Shielded Tent

Figure 3 – Shielded Tent
(courtesy of Select Fabricators)

Figure 4 SCIF Shielded Information Facilities

Figure 4 – SCIF Shielded Information Facilities
(courtesy of Armag)

 

Faraday Cages come in all sort of sizes and configurations. A typical Faraday Cage is an electromagnetic shielded enclosure usually constructed or lined with metal, Figure #2. A variation of a typical shielded enclosure is a shielded tent constructed of electrically conductive fabric, Figure #3. In addition to being conductive, a shielded enclosure also needs to incorporate shielding products such as: honeycomb vent panels for airflow, conductive windows for viewing, and conductive gaskets for access doors, connectors, antenna mounts, power/signal entry panels, etc…. Power and signal lines entering the shielded enclosure also need to be electromagnetically filtered to prevent unwanted conducted emissions. Internal to the shielded enclosure structural seams between the floor and wall, wall to ceiling, and all corner seams need to be electromagnetically sealed either by welding, conductive gaskets, or conductive caulk. At this point, from the need of all the shielding products, you might have realized that the principle of a shielded enclosure is to provide a complete low impedance path by addressing all entry, exit, and structural apertures. Shielding products therefore provide an electrically conductive, low impedance, path allowing the electromagnetic field to propagate on the outer surface of the shielded enclosure or on the inner surface if the electromagnetic field is generated from electronic equipment within the shielded enclosure. Therefore, shielding of an enclosure enables the internal electronic systems to be less susceptible to outside radiated emissions and covert to outside radio receivers and other detectors attempting to receive information.

An example of a shielded enclosure that generates internal electromagnetic fields that carry confidential information is a SCIF (Sensitive Compartmented Information Facility), Figure #4. A SCIF is a shielded enclosure used to process “Sensitive Compartmented Information (SCI)” material. SCIF shielded enclosures are used for U.S. Intelligence worldwide for classified information concerning intelligence sources, methods, or analytical processes; the information and material must be treated with correct classification and be protected.

Faraday Cages such as SCIF, conductive tents, and manned or unmanned electronic system enclosures require shielding products to meet TEMPEST and other military EMC (electromagnetic compatibility) specifications. As previously mentioned, these specialized conductive shielding products enable ventilation Figure #5, viewing Figure #6, and conductive gaskets for entry/exit doors, connector panels, structural seams, power and signal entry panels, etc…, Figure #7; in addition to power and signal filtration Figure #8.

Figure 5 Honeycomb Ventilation Panels

Figure 5 – Honeycomb Ventilation Panels
(courtesy of MAJR Products Corp.)

Figure 6 Conductive Windows

Figure 6 – Conductive Windows
(courtesy of MAJR Products Corp.)

Figure 7 EMI/RFI gasket products

Figure 7 – EMI/RFI gasket products
(courtesy of MAJR Products Corp.)

Figure 8 EMI/RFI filters

Figure 8 – EMI/RFI filters
(courtesy of Corry Micronics Inc.)

EMI Gaskets: Die-Cut, Water Jet & Flash Cutting


EMI gaskets are used in a variety of electronic devices where EMI/RFI is an issue including communications, military electronics, and RF applications.

When it comes to manufacturing EMI gaskets, there are three different methods MAJR Products uses:

1. Die-Cut
2. Water Jet
3. Flash Cutting

Each of these three manufacturing techniques have specific benefits associated with them and are best suited for a plethora of different products and materials including:

  • Conductive materials
  • Rubber
  • Cork
  • Foils
  • Silicones
  • Neoprenes
  • Porons
  • Thermal Materials
  • Tapes
  • Thin Films
  • Mylar
  • Kapton

1. Die-Cut

Die-cutting is a high-speed method of using a die to shear webs of low-strength materials in order to mass produce a wide range of industrial products, including gaskets. MAJR creates a predesigned steel rule die of the item, and then uses a press to replicate the item with the chosen material.

Benefits of the Die-Cut Method

  • Cost effective.
  • Good for high-volume orders.
  • Allows tight tolerances and accuracy.
  • Ability to manufacture gasket configurations of any shape or size.
  • It can handle a variety of different materials for manufacturing gaskets, including:

Items Typically Created via the Die-Cut Method

  • Gaskets
  • Washers
  • Insulating foam
  • Vehicle parts

2. Water Jet

The water jet process of creating items, including gaskets, involves high pressure water that is forced through a small nozzle (0.010″ to 0.015″ in diameter) to produce a very precise cut of the material.

Benefits of the Water Jet Method

  • Gaskets can be tightly nestled.
  • Cuts are extremely accurate.
  • A good method for complex and intricate parts.
  • Provides an efficient use of raw materials.
  • Less chance of compression distortion.
  • Works well for producing prototypes and other test parts.
  • A great method for short production runs.
  • Very clean process because you are only using water.

Items Typically Created Via the Water Jet Method

  • Gaskets
  • Textiles
  • Rubber
  • Foam
  • Plastics
  • Composites
  • Metal

3. Flash Cutting

If the gaskets you need require thicknesses from .001” to .75” with tight tolerances MAJR utilizes the flash cutting method. The flash cutting method requires the use of a CNC machine that holds a blade in place to accurately and cleanly cut through the production material. Flash cutting results in a product with exact and precise measurements. Flash cutting also allows us to produce prototypes from CAD or PDF files.

Benefits of Flash Cutting

  • Allows for many customization options.
  • Can hold tolerances to .005”
  • Offers the fastest production turn-around time.
  • Exceptional for high volume applications.
  • The best method for projects where product aesthetics are important.
  • Does not cause concavity.
  • Produces clean edges.
  • Excellent for projects that require rapid prototyping.
  • Can utilize a variety of materials with the flash cut method.
  • Can be more cost-effective than jet cutting and die-cutting.

Items Typically Created via Flash Cutting

  • Gaskets
  • Soft plastics
  • Rubber
  • Laminated materials
  • Foam
  • Industrial fabrics
  • Technical textiles
  • Paper

MAJR Products Would Love To Take Care Of Your EMI Gasket Needs!

MAJR Products is an internationally recognized manufacturing leader of EMI/RFI shielding products, including gaskets. We have been serving the electronics industry by providing electromagnetic interference shielding products and solutions to some of the largest defense contractors in the country for close to 25 years.

We offer a wide variety of EMI gaskets, including:

  • EMI Connector Gaskets
  • Shield Seal Strip EMI Gaskets
  • Wire Mesh Gaskets
  • Custom Die-Cut Shielding Gaskets
  • Custom Molded Gaskets
  • Custom O-Ring Gaskets
  • Metallized Fabric Shielding EMI Gaskets
  • Fingerstock Gaskets
  • Rigid Mount Frame EMI Gaskets
  • Mesh Over Elastomer EMI Gaskets

To request a quote, fill out our simple form, and one of our representatives will be in touch with you shortly. You can also request samples of our many top-notch products.

REQUEST A QUOTE

Honeycomb Waveguide panels are often used in the electronics industry

Honeycomb Waveguide Panels

Honeycomb Waveguide – An Attenuation Performance Explanation of a MAJR Products Honeycomb Waveguide Panel due to the Effect of a Waveguide Beyond Cuttoff Principle

What is a honeycomb Waveguide panel?

A shielding honeycomb waveguide panel is a product that lets air flow into and out of an EMI/RFI shielded enclosure. The entering fresh air may be either cooled, heated, or at ambient temperature depending on the shielded enclosure environment and contents. For electronic equipment, the primary reason for airflow is usually to cool electronics; if a manned military shelter the reason is to circulate fresh air and to either cool or heat the air depending on the external environment.

How a shielded honeycomb waveguide panel attenuates

Depending on the wavelength of the electromagnetic wave entering the honeycomb waveguide panel, every cell of the metal honeycomb core provides attenuation (shielding) to that electromagnetic wave and is described as a waveguide below cutoff.

Each individual honeycomb cell acts as a waveguide and because the honeycomb cell aperture (height and width) is much smaller than a half wavelength of the electromagnetic wave entering the honeycomb, the honeycomb cell attenuates the wave.

Attenuation is accomplished by increased wave impedance and reflection cancellation as the electromagnetic wave propagates through the honeycomb waveguide thickness and number of cells. The thicker the honeycomb cell, the more attenuation the honeycomb panel will provide, therefore an approximation is Attenuation (dB) = 28 x Thickness / width.

Depending on the polarization of the electromagnetic wave, the only frequencies of the electromagnetic wave that pass without attenuation through the honeycomb cells are those that have a half wavelength dimensionally smaller than the diagonal dimension of the cell.

Applications of a Shielded Honeycomb Waveguide Panel

  • Custom honeycomb panels designed to meet specific shielding, airflow, and mounting requirements.
  • Honeycomb is available in aluminum or steel with tin, nickel, or chromate(aluminum) to meet specific attenuation and environmental requirements of MIL-STD-461 and MIL-STD 810.
  • High permeability steel honeycomb available for magnetic (H-Field) shielding to 60 dB attenuation levels. (>80 dB attenuation using 1 in. thick tin plated steel honeycomb).
  • Standard and custom sizes and mounting configurations available.
  • An EMI/RFI gasket is always supplied as an integral part of the honeycomb vent panel assembly.
  • Honeycomb panel mounting is accomplished with either frame thru-holes or captive fasteners located and installed to standard or custom dimensions.

To learn more about MAJR’s Honeycomb Waveguide Panels or other products, like: EMI/RFI Shielded Ventilation Panels, EMI/RFI Shielded Fan Ventilation Panels, EMI/RFI Shielded Air Filtration Panels, or EMI/RFI Shielded Honeycomb Ventilation Panels, visit our website and fill out the form or call us at 877-625-6033.

MAJR Products – Blog – ConnectorGasket.com: The Convenient, Quick, and Cost-Effective Way to Order Connector Gaskets Online

An engineer and a purchasing manager holding a tablet discuss what size connector gaskets to order from ConnectorGasket.com.

ConnectorGasket.com: The Convenient, Quick, and CostEffective Way to Order Connector Gaskets Online

When ordering connector gaskets, military contractors and electronics, IT, andtelecommunication companies often find it challenging to find suppliers that both offer a comprehensive range of gaskets and can deliver orders within a short period of time. As a result, procurement professionals, purchasing managers, and others responsible for buying materials frequently spend hours researching suppliers looking for one that can cater to their specific needs. Since it is so difficult to find the combination of choice, quality, speed, and cost-effectiveness, it is not unusual for them to have to order from multiple suppliers to meet their various requirements.

ConnectorGasket.com

That is why in June, we launched our new website, ConnectorGasket.com. It is specifically designed to provide our customers with a convenient, quick, and cost-effective way to fulfill all their connector gasket needs with just a few swipes, taps, or clicks.

To cater to the needs of customers from the military, consumer, industrial, instrumentation, and medical electronics sectors, as well as from the IT and telecommunications industries, we offer affordable QPL-qualified gaskets and commercial grade gaskets. There are currently four styles available for online purchase:

  • The MIL-DTL 38999 series
  • The M83528 series
  • The MIL-DTL 5015 series
  • The D-Subminiature series

By creating their own accounts, customers can keep track of their orders and easily re-order when needed. Plus, by selecting the two-day delivery option, customers never have to hold up their production cycles due to late deliveries, thereby ensuring they can fulfill their own orders as scheduled. Companies that have factored long delivery times into their own production cycles—and by extension, into their order fulfillment capabilities—can leverage our fast delivery to reduce their production cycle times and offer their own customers speedier turn-around.

Customers are also encouraged to visit our main site, MAJR Products, where we offer many other types of gaskets, including military EMI/RFI shielding gaskets and custom-made gaskets that can be manufactured to companies’ precise specifications.

Interested to learn more? Go to ConnectorGasket.com to browse our products, place your first order, or request more information.

Sources:
Creative brief
Press release June 19

Connector Gaskets

Shielding For RF And Microwave Applications

Understanding Shielding for RF and Microwave System Applications

Any electronic device emits some level of electromagnetic radiation. Electromagnetic interference (EMI) shielding and radio frequency interference (RFI) shielding products are used when the EMI/RFI of an electronic product or system, in particular high frequency operations, necessitates attenuation of EMI/RFI to a specific level; the attenuation of a radiated emission to a certain level is designated in industry as shielding. MAJR Products EMI/RFI shielding solutions are able to meet even the most stringent EMC requirements.

Why Shielding Products Are Necessary

Understanding antennas and electromagnetic fields is the first step to understanding EMI/RFI shielding. EMI/RFI shielding is important for achieving electromagnetic-compatibility (EMC) for electronic products including digital systems. EMC design is concerned with preventing electronic devices from not interfering with its own operation (crosstalk) in addition to the reduction of electromagnetic radiation that may interfere with other electronic equipment and systems when operating in an intended environment.

EMC design also involves preventing circuits from misbehaving as a result of ambient EMI/RFI from communication towers, aircraft, radio stations, etc… With digital systems’ ever-increasing frequencies and edge rates, EMC is becoming harder to achieve.

The shielding products produced by MAJR Products can be designed and manufactured to suit the unique needs of specific customer applications. In addition, with experience designing custom EMI/RFI shielding products, the engineers at MAJR Products offer customers flexibility from design, through prototyping / test, and into production.

A Wide Range of Microwave Absorber Materials

While EMI/RFI Shielding has long been a requirement for military applications’ such as in high frequency electronics, there is also a growing need for microwave absorbing materials in consumer electronics such as wireless LAN devices, network servers, video equipment etc. Depending on the requirements of the application, microwave absorbing material can be tuned to function best at specific frequencies or designed to be used across a broadband frequency range. Along with tuned microwave absorber materials, Broadband microwave absorbing material is used in electronic products for a wide variety of markets including cellular and telecom, RFID tags, electronic devices, radar cross section reduction, and a variety of other antenna and electronic enclosure applications.

Broadband Microwave Absorber Material and Board Level Shielding from MAJR Products

For shielding of RF and microwave applications, MAJR Products 6500 series Broadband Microwave Absorber material product line utilizes material that is elastomer-based, ultra-soft, thin, flexible, and easy to install in even the tightest of applications or irregular surfaces. This absorber can be supplied die cut or water jet cut to meet the exact product specifications. In addition, for installation ease the absorber can be supplied with a pressure sensitive adhesive, typically requested for use in general to high altitude or high vibration applications.

MAJR Products’ Board Level Shields (BLS) are manufactured specifically to meet the requirements of an individual project, we offer the following:

  • Custom Tailored Configurations: using Precision Photo Etching or Stamping techniques, MAJR can supply custom tailored solutions in a matter of weeks.
  • Multiple Types/Materials: diverse material options and styles mean you can select the configurations and features needed for your application. Available materials include:
    • Nickel/Silver
    • Tin/Steel
    • Brass
    • Copper
    • Magnetic Shielding Material
    • Others per request
  • Special Design Features/Finish: providing flexibility for mounting, solder techniques, pick and place automation, lid placement alignment, marking, and overall dimensional flexibility.

Contact MAJR Products For A Quote On Shielding Products For RF And Microwave Applications

See how MAJR Products can solve your electronics shielding equipment needs. Contact us for additional product information, free sample products, or to receive a quote on shielding solutions for RF and microwave applications.