FAQs

Micro-Coax helps customers with their EMC needs by providing protection from EMI/EMP/Indirect Lightning Effects for their wire and cable runs or harnesses. This protection comes in the form of a braided or woven material made from ARACON brand metal clad fibers and backed by a half century of RF/microwave transmission line experience. The braided or woven ARACON material is applied by either sliding over or wrapping around the wire and cable bundles and then electrically grounding. Electrical ground connections are typically made to the rear of the connector shells.

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A revolutionary product, available only from Micro-Coax that combines the conductivity of an outer metal coating with the strength, light weight, and flexibility of aramid fibers. ARACON is manufactured by plating DuPont KEVLAR® fibers, a material well known for its use in bullet-resistant vests, high-speed boats and military helmets. With the addition of nickel, copper and silver coatings of varying thicknesses, ARACON fibers provide a versatile combination of physical and electrical properties for a variety of demanding applications.

KEVLAR® is a registered trademark of E.I. du Pont de Nemours and Company

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Aramid fibers, such as KEVLAR®, are a class of heat-resistant and strong synthetic fibers. They are used in aerospace and military applications for ballistic rated body armor fabric and ballistic composites, in bicycle tires, and as an asbestos substitute. The name “aramid” is derived from merging of “aromatic polyamide”. They are fibers in which the chain molecules are highly oriented along the fiber axis, so the strength of the chemical bond can be exploited.

KEVLAR® is a registered trademark of E.I. du Pont de Nemours and Company

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EMI (Electromagnetic Interference) is any electromagnetic emission from a device or system that interferes with the normal operation of another device or system. When EMI was first recognized, most interference problems were experienced with radio signals, and hence, were referred to as radio frequency interference (RFI). Today, EMI refers to electromagnetic interference in its broadest sense. EMI may be introduced intentionally as in the case of electronic warfare, or unintentionally from an electronic device.

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EMP (Electromagnetic pulse) is a burst of electromagnetic radiation that results from an explosion (usually from the detonation of a nuclear weapon) and/or a suddenly fluctuating magnetic field. The resulting rapidly changing electric fields or magnetic fields may couple with electronic systems to produce damaging current and voltage surges.

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Indirect lightning effects refers to the damage to or malfunction of electronic systems that results from a nearby lightning flash. These effects may range from tripping a circuit breaker to physical damage of input or output circuits on electronic equipment.

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EMC (Electromagnetic Compatibility) requires that electronic systems be able to tolerate a specified degree of interference (EMI/EMP/Indirect Lightning Effects) and not generate more than a specified amount of interference. EMC is becoming more important because there are so many more opportunities today for EMC issues.

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All electronic devices and systems are regulated to be able to tolerate a specified degree of interference and not generate more than a specified amount of interference.

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Shielding the interconnecting wire and cables is an important part of any EMC design, especially in systems that require compliance to EMP and/or Indirect Lightning Effects. Shielding is typically handled by enclosing the wire and cables inside of a grounded metal structure (faraday cage). The metal structures can vary from metal conduit to wire braids. The actual shielding effectiveness and transfer impedance will depend on the properties of the material, degree of coverage, and geometry.

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Shielding effectiveness measure of the reduction or attenuation in electromagnetic field strength at a point in space caused by the insertion of a shield between the source and that point. Usually stated in dB.

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For a specified cable length, transfer impedance relates a current on the surface of a shield to the voltage drop generated by this current on the opposite surface of the shield. All other things being equal, shields with lower DC resistance will have a lower voltage drop and thus lower transfer impedance. Transfer impedance is used to determine shield effectiveness at lower frequencies (< 1 GHz) against both ingress and egress of interfering signals. Cable shields are normally designed to reduce the transfer of interference, hence, shields with lower transfer impedance are more effective than shields with higher transfer impedance.

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  • First and foremost, proof that it will shield the unwanted interference.
  • Easy to apply over the wire and cables.
    • Flexible
    • Handle split outs
    • Not damage the underlying wire and cables
  • Easy to terminate.
    • Cut without special tools
    • Able to establish a good ground
    • No special adapters required
  • Add minimal weight and size.
  • Provide additional mechanical protection for the underlying wire and cables.
  • Tough enough to withstand the environment.

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Manufacturers of:

  • Civil and military manned and unmanned aircraft (fixed and rotary wing)
  • Spacecraft
  • Missiles
  • Rockets
  • Blimps
  • Racing vehicles

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To achieve the needed return on the additional investment required of ARACON, the application must typically involve extended use at high altitude and/or velocity and involve vital sensitive electronic equipment vulnerable to interference, especially if in close proximity to other electronic equipment. An even greater benefit can be achieved if the application involves composite structures where the previous metal structure provided shielding from the external environment.

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Greater strength with less weight. The specific gravity of aramid fibers is only 1.44 g/cc, compared to copper at 8.9 g/cc. Even with the addition of metal coatings, the specific gravity of ARACON fibers ranges from 3 to 5 g/cc. At the same time, the tensile strength of the aramid core (350 Ksi) is from three to ten times higher than that of traditional or high-strength copper cores (35-95 Ksi).

Flexibility that never tires. Since ARACON fibers are textile-like at heart, they offer a feel that is far more flexible and compliant than metal. And, in a side-by-side flexibility test, copper wire broke after 50 flexes, while ARACON fiber was still going strong when the test was stopped at 10,000 flexes.

Stability and compatibility. Aramid fibers have dramatically improved thermal stability compared to commodity fibers such as nylon and polyester. ARACON maintains its strength both at elevated temperatures and under cryogenic conditions. Moduli of aramids are in the same range as common conductor metals. This makes aramids ideal substrates for cladding with conductor metals. Thermal cycling tests show no increase in resistance, confirming the excellent adhesion of metal to the aramid.

Electrical/mechanical properties tailored for your needs. A wide range of properties is available by varying the metal cladding type, thickness and the base fiber size. Strands from 38 AWG to larger than 24 AWG can be made from single or multiple bundles of ARACON. Fiber resistance can be tailored from 100 to greater than 500,000 ohms per thousand feet.

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  • Any braided or woven covering made from ARACON brand metal clad fibers.
  • ARACON EMI Shielding Solutions are only available from Micro-Coax, Inc., a leading supplier of high performance low loss microwave cable and cable assemblies for nearly a half century.

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More uniform coverage. The textile-like properties of ARACON fibers contribute to extremely effective, uniform shield coverage. The large number of very fine fibers, together with the tendency of yarn bundles to flatten and spread, makes it easy to obtain high coverage levels with reduced windowing. Ease of pushback is maintained even at high coverage.

Better high-frequency shielding. The fine ARACON fibers provide a very high surface-to-volume ratio. Together with the excellent coverage, the extra surface yields improved high-frequency EMI shielding performance. For lower frequencies, a hybrid of metal wire and ARACON fibers offers good performance with weight savings.

Reduced weight. In a typical case, switching to ARACON fibers allows a weight savings of 60% in the braid, which translated to an overall reduction in cable weight of 26%. Weight savings can be especially important in aerospace and similar applications where every ounce counts.

Flexibility. Braid made from ARACON fibers has successfully replaced copper braid in military applications where ease of movement and durability were critical.

Compatibility. Yarns of ARACON fibers are fully compatible with standard braiding equipment. Shields made with ARACON fibers can be terminated by soldering or with band straps.

Ease of assembly. Shields made with ARACON fibers can be terminated by soldering or with band straps. The braids can be easily expanded or reduced to tightly fit a large range of fittings for termination. No special tooling required for assembly. ARACON fibers can be cut with a scissors.

Made in the USA. Available anywhere in the world.

Heritage. ARACON brand metal clad fibers have more than a decade of heritage flying in space. Micro-Coax has nearly a half century of RF/microwave transmission line experience.

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