Electricity: electrical systems and devices – Housing or mounting assemblies with diverse electrical... – For electronic systems and devices
Reexamination Certificate
2003-03-03
2004-11-16
Zarneke, David A. (Department: 2827)
Electricity: electrical systems and devices
Housing or mounting assemblies with diverse electrical...
For electronic systems and devices
C361S816000, C361S704000, C361S709000, C174S034000
Reexamination Certificate
active
06819572
ABSTRACT:
BACKGROUND
1. Field
The present disclosure relates to reducing electromagnetic interference (EMI) radiated by a heatsink and, more particularly, to a circuit for at least partially reducing such EMI.
2. Background Information
Electromagnetic interference (EMI) may be characterized as an interfering signal generated within or external to electronic equipment. Typical sources could be, for example, power-line transmissions, noise from switching devices, and/or spurious radiation from oscillators. EMI signals may, directly or indirectly, contribute to degradation in performance of an electronic receiver or system. In order to reduce degradation in performance of an electrical device by EMI, such as generated from a second electrical device, electronic equipment typically meets EMI levels set by the Federal Communications Commission (FCC) and the International Special Committee on Radio Interference (CISPR).
EMI emissions are usually a problem where the interfering signal travels from a source via a coupling path and radiates to a device. This device may have its performance thereby affected. To illustrate the concept, the following example may prove helpful. Of course, one skilled in the art will recognize that there are many other examples that may be used. In a computing system, EMI signals generated by a microprocessor, for example, may be transmitted to a heatsink coupled to the microprocessor. The heatsink, effectively acting as an antenna, may than radiate the received EMI signals. These radiated EMI signals may then degrade the performance of an electrical device within the affected range.
Typically, reduction of electromagnetic interference is attempted via passive technology, meaning here employing an inert component or method that may control, but not create or amplify energy. While these passive methods are typically inexpensive, at times they are ineffective or have been demonstrated to provide only limited success at reducing EMI signals. These methods, for example, may have inherent bandwidth limits and/or resonant points which may limit the frequencies of EMI signals that are capable of being reduced. In addition, if the source of the EMI signals is changed, due to a processor upgrade, for example, often a complete redesign of the passive method is called for to be effective. A need, therefore, exists for an improved circuit configuration or technique for implementing an electromagnetic noise suppression device.
REFERENCES:
patent: 4933605 (1990-06-01), Quazi et al.
patent: 5023525 (1991-06-01), Kriz
patent: 5457300 (1995-10-01), Karino et al.
patent: 5638895 (1997-06-01), Dodson
patent: 5703416 (1997-12-01), Hinkle et al.
patent: 6044899 (2000-04-01), Langley et al.
patent: 6122169 (2000-09-01), Liu et al.
patent: 6134505 (2000-10-01), Smith
patent: 6208516 (2001-03-01), Fangonilo et al.
patent: 6243680 (2001-06-01), Gupta et al.
patent: 6583682 (2003-06-01), Dubhashi et al.
patent: 2001/0026440 (2001-10-01), Mellberg et al.
patent: 2002/0079566 (2002-06-01), Majid et al.
patent: 197 18 649 A 1 (1998-11-01), None
patent: 0 853 340 (1998-07-01), None
patent: 58214256 (1983-12-01), None
Scout Justin B.
Tran Thanh Y.
LandOfFree
Electromagnetic noise suppression device does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Electromagnetic noise suppression device, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Electromagnetic noise suppression device will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3274278