RF EMI Shielding-Helping Our Systems Work Well TogetherRandy Mitchell (VTech)
You know how it is in the workplace. If one works in a “cubicle farm” with large open spaces and no privacy, all of the ambient noise created by co-workers makes it very hard for one to concentrate on the project at hand. The noise and interference present in the environment make doing one’s best work much harder. It’s nicer and more efficient to have a private office, protected from outside distraction by four walls, a ceiling, and a door. Though you are only inches away from the cacophony and disruptive noise of co-workers, complete concentration on the task at hand is possible due to the shielding from distraction that walls, ceiling and door of the office provide.
An interesting analogy to the workplace example is an electrical product like a computer, with many electrical components in close proximity, all working at the same time on different functions. Each one of these electric components emits RF (Radio Frequency interference) and EMI (ElectroMagnetic Interference) while performing its function. This interference/noise can negatively impact the operation of nearby modules, making them perform at less than optimum performance. In order to optimize the function of each component and make the “team” function smoothly, the disruptive interference needs to be lessened or eliminated. To continue the analogy, through good engineering and development, RF and EMI can be minimized with good grounding and shielding of the electrical components, essentially giving each component a “private office” in which to do its work without being interfered with by the other components. The cords and cables connecting the peripheral components in the system should also be shielded to keep unwanted RF and EMI energy from entering or leaving the component like the “doors and hallways” of an office, preventing undesirable interference elsewhere throughout the system. The net result is all components working together as a smoothly functioning device.
If the device is enclosed in a cabinet, the cabinet itself should be shielded to prevent the inclusion of the “background” RF and EMI which is always present in our environment. This “shielded cabinet” prevents “background interference” from causing any interference to the device, while simultaneously preventing the enclosed device from emitting any RF and EMI to the outside environment. Among of the best shielding options available are metalized fabrics and textiles, which are very thin, flexible, adaptable(and able to be laminated), lightweight, corrosion resistant, and yet able to contain the emission of and stop the penetration of RF and EMI. Today’s conductive textiles and shielding fabrics are a lightweight and flexible solution to a heavyweight engineering problem.
V Technical Textiles, Inc.
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