electromagnetic interference

The United States Joint Strike Fighter Program Office has requested the Australian Defence Science and Technology Organisation (DSTO) to study the effect of electromagnetic compatibility and interference on a full-scale model of an F-35A Joint Strike Fighter aircraft.

Global Industry Analysts (GIA) Inc. has released a comprehensive report on the global EMI and RF shielding materials and technologies markets. The report states the forecast of this market will reach $7.9 billion by 2020.

Today’s electrical and electronic devices are subject to mandatory EMC requirements throughout the world. Many devices operate at high frequencies and are very small. They are placed in nonconductive plastic cases providing no shielding. Essentially, all these devices cannot meet these mandatory requirements or they may cause interference to other devices or receive interference causing susceptibility problems without a proper program of EMI control. This program consists of identifying the “suspect” components and circuits that may cause or be susceptible to EMI. This is completed early on in the program to allow for an efficient design in keeping the cost of dealing with EMI as low as possible. A complete EMC program consists of proper filtering, grounding and shielding. This article will discuss the latter, but the other factors cannot and will not be ignored or given insufficient priority.

Overview of EMI Shielding Compounds

Electromagnetic radiation that adversely affects device performance is generally termed EMI (ElectroMagnetic Interference). Interference takes many forms such as distortion on a television, disrupted/lost data on a computer, or “crackling” on a radio broadcast. Many electronic devices not only emit electromagnetic fields which might cause interference in other systems, but they are also susceptible to stray external fields which could affect its performance. As a result, they must be shielded to ensure proper performance.