| 摘要 |
<p>The screening is against R.F. interference for electrical cables. The cable screen extends the frequency range of conventional methods by about 103 and decreases the transfer impedance over this frequency range again by about 103. The screen consists of three or more layers forming a sandwich of high conductivity and high permeability materials. A typical screen is made up of 35 micron copper, or some other high conductivity metal, ribbon silvered to a depth of 2 microns followed by a 25 micron thick high permeability material again in ribbon form and finally a further 25 micron copper ribbon plated as the first. The high permeability material may be, for example, mu - metal (RTM), permalloy (RTM), pure iron etc.</p> |
