Cable offers customized EMI shielding.
Press Release Summary:
LEONI Tailor-Made Cable shields from electromagnetic interference using braided and/or wrapped-foil shields to complex multi-layer designs. Materials include copper and high conductivity metals as well as soft-magnetic alloys that absorb low impedance and magnetic fields. For high-density cabling configurations inside ducts, trays, robots, and tight enclosures, internal shielding of individual conductors or conductor groups can be provided, along with twisting and cabling options.Original Press Release:
Tailor Made Shielding Protects Cables Against Electro-Magnetic Interference
Fairfield, NJ, December2003 - Shielding against electro-magnetic interference (EMI) is as important a consideration as any other property in industrial and non-industrialized cable applications, or should be. LEONI Tailor-Made Cable (LTMC) offers customized EMI shielding to cope with virtually any EMI requirement. To pick the appropriate shielding for a given EMI scenario, LEONI TMC engineers select from a wide variety of materials and designs. They range from braided and/or wrapped-foil shields to complex multi-layer designs. Materials employed embrace all kinds of copper and other high conductivity metals as well as proprietary soft-magnetic alloys to absorb low impedance and magnetic fields.
One in four LEONI TMC customers specify a tailor-made cable solution because their application requires special EMI attention. Many of these clients are from the machinery, sensing and control and communication technologies sectors. Superior EMI performance is of particular importance in medical electronics. In imaging diagnostics, low-level analog signals must be protected from interference caused by the strong fields that originate from the same instrument (e.g. x-ray or computer-tomography equipment).
Shielding suppresses the induction, generation and propagation of interference and unwanted signals. Because of their relative length, cables are the system components highly vulnerable to
interference. Longer cabies act like antennas that pick up signals from various sources - even from radio stations or cell phones. Shields protect conductors so they cannot act as antennas.
Another common electro-magnetic threat arises when power cables and signal or control cables are run in parallel in cable ducts or trays or where high-density cabling configurations are installed in confined spaces such as tight enclosures or robots. Power and signal lines are even closer when combined in special hybrid cables. Here, intelligent grouping of conductors, internal shielding of individual conductors or conductor groups and certain twisting and cabling options can be used to
limit electromagnetic interactions. Unshielded cables easily become EMI victims if routed close to switching power supplies or RF-equipment of any kind!
There are solutions for all types of electro-magnetic interference. LEONI TMC works with metallized foils, round and flat wires or even corrugated tubing. Small shielding elements like shielding wires are arranged in served groups or bundles or as classical braided shields. Semi-conductive plastics or
metal-loaded compounds may be used to enhance shielding as required. Precise prediction of shielding attenuation and surface transfer impedance of shield designs, backed up with a large database, helps to avoid pitfalls. For verification, cable shielding properties can be measured with good accuracy and repeatability, over a range of frequencies extending up to the lower microwave ranges. Such measurements reveal, for example, that the optical coverage of a shield is not always sufficient to ensure a good shield. Braiding and serving angles and measures to reduce unwanted longitudinal inductances are as important as increasing size, mass and coverage of shields.
Utilizing the entire shielding know-how results in tailor-made-cable solutions that can handle EMI - and are slim, flexible and durable at the same time. Tailor-made specialty cables with optimal EMI performance are designed and manufactured by LEONI Tailor-Made Cable for orders as small as 300 ft., with time from analysis to delivery taking no more than 3-6 weeks.
