Electronic equipment leaking radiation and electromagnetic interference from other electronic devices not only serious work properly, causing the device dysfunction, transmission errors, but also a threat to human health and safety of search, great harm. Thereby reducing electromagnetic interference (EMI) of electronic devices has been an issue that must be considered. Absorption ring, known as a ferrite bead, referred ring. It is commonly used in anti-jamming electronic circuit components, high-frequency noise has a good inhibition, generally used ferrite material (Mn-Zn) is made. Ring at different frequencies have different impedance characteristics, usually in the low frequency impedance is very small, when the signal frequency increases impedance magnetic performance dramatically. We all know that the higher the frequency, the more likely to radiate out (to buy high-quality computer chassis is to reduce electromagnetic leakage), and general signal lines are no shield, then it would be a good signal lines antenna receiving various clutter surrounding high-frequency signals, and these signals are superimposed on the original transmission of the signal, and even change the original transmission of the useful signal. So in ring action, so that the normal useful signal by good, but very good suppression of high-frequency interference signals, and low cost.
