| 摘要 |
PROBLEM TO BE SOLVED: To realize by using a common mode choke coil a real clean electromagnetic environment which substantively reduces noise radiating from electronic equipment, and which does not rely on a reduction of a noise measured value by clock frequency diffusion. SOLUTION: The noise reduction electronic equipment of the present invention has an electronic equipment body with a signal generator shielded by a shield case, a port for taking out a signal outside through the shield case, and a common mode choke coil for preventing radiated noise connected to a transmission line connecting the signal generator and the port. The common mode choke coil is arranged inside or outside of a shield surface of each port on a substrate situated within a 1/4 wavelength of a signal frequency from the shield surface or within a connector. A common mode impedance of the common mode choke coil is set equal to or more than 377Ω, so that a radiated noise is reduced. Thus, the noise reduction electronic equipment is realized. COPYRIGHT: (C)2009,JPO&INPIT
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