Electricity: electrical systems and devices – Housing or mounting assemblies with diverse electrical... – For electronic systems and devices
Reexamination Certificate
1998-06-19
2001-01-30
Gandhi, Jayprakash N. (Department: 2841)
Electricity: electrical systems and devices
Housing or mounting assemblies with diverse electrical...
For electronic systems and devices
C361S728000, C361S752000, C361S816000, C174S034000, C174S034000
Reexamination Certificate
active
06181572
ABSTRACT:
TECHNICAL FIELD OF THE INVENTION
The present invention relates generally to the field of digital subscriber line (xDSL) modems and, more particularly, to a digital subscriber line (xDSL) modem having a multi-layer electromagnetic shield and method of manufacture.
BACKGROUND OF THE INVENTION
Digital Subscriber Line (xDSL) modems provide the ability to transmit data at high rates across twisted pair telephone wiring. The electronic circuitry and frequencies required to accomplish this task can generate substantial electromagnetic (EM) radiation. Such EM radiation can be problematic because a device that exhibits high EM radiation can fail to satisfy United States Federal Communications Commission (FCC) requirements for electronic devices. Furthermore, high EM radiation can interfere with the operation of other electronic equipment.
Some conventional xDSL modems address the EM radiation problem by forming the housing for the xDSL circuitry out of a relatively thick conductive material, such as cast metal. Typically, such systems are effective in sufficiently curbing the EM radiation. However, for some applications, it is desirable to create the modem housing out of composite, plastic, or other non-conductive material. For example, such housings may be used to create light-weight, less expensive devices for the mass market. Such a composite or plastic housing is generally ineffective in preventing EM radiation.
One conventional method for blocking EM radiation is to use a metal spray coating, for example a copper spray coating, applied to the inner surface of the composite or plastic housing. Such coatings are helpful but can sometimes fail to sufficiently reduce the EM radiation. Furthermore, the metal spray coating can be a time consuming and expensive process step.
SUMMARY OF THE INVENTION
In accordance with the present invention, a digital subscriber line (xDSL) modem having a multi-layer electromagnetic shield and method of manufacture are disclosed that provide significant advantages over prior developed EM shielding methods for xDSL modems.
An xDSL modem assembly is provided that includes a housing and a circuit board having xDSL electronics. A multi-layer electromagnetic shield is formed to receive the circuit board. The circuit board is positioned inside the multi-layer electromagnetic shield, and the multi-layer electromagnetic shield is positioned inside the housing.
It is a technical advantage of the present invention that EM radiation from an xDSL modem can be substantially reduced at a low per unit cost and with a relatively simple manufacturing step. In particular, EM radiation from an xDSL modem having a composite, plastic, or other non-conductive housing can be reduced using the multi-layer electromagnetic shield. This reduction can, for example, be approximately 30 dB.
Other technical advantages should be apparent to one of ordinary skill in the art in view of the specification, claims, and drawings.
REFERENCES:
patent: 3532827 (1970-10-01), Ewin
patent: 3821484 (1974-06-01), Sternung et al.
patent: 4002849 (1977-01-01), Kotler et al.
patent: 4282408 (1981-08-01), Stauers
patent: 4438511 (1984-03-01), Baran
patent: 4665514 (1987-05-01), Ching et al.
patent: 4670347 (1987-06-01), Lasik et al.
patent: 4679227 (1987-07-01), Hughes-Hartogs
patent: 4723267 (1988-02-01), Jones et al.
patent: 4731816 (1988-03-01), Hughes-Hartogs
patent: 4757495 (1988-07-01), Decker et al.
patent: 4782512 (1988-11-01), Hutton
patent: 4833706 (1989-05-01), Hughes-Hartogs
patent: 4841561 (1989-06-01), Hill
patent: 4949355 (1990-08-01), Dyke et al.
patent: 4980897 (1990-12-01), Decker et al.
patent: 5005106 (1991-04-01), Kiku
patent: 5025469 (1991-06-01), Bingham
patent: 5054034 (1991-10-01), Hughes-Hartogs
patent: 5119402 (1992-06-01), Ginzburg et al.
patent: 5134611 (1992-07-01), Steinka et al.
patent: 5185763 (1993-02-01), Krishnan
patent: 5198818 (1993-03-01), Samueli et al.
patent: 5199071 (1993-03-01), Abe et al.
patent: 5202884 (1993-04-01), Close et al.
patent: 5206886 (1993-04-01), Bingham
patent: 5214650 (1993-05-01), Renner et al.
patent: 5222077 (1993-06-01), Krishnan
patent: 5228062 (1993-07-01), Bingham
patent: 5247347 (1993-09-01), Litteral et al.
patent: 5282155 (1994-01-01), Jones
patent: 5285474 (1994-02-01), Chow et al.
patent: 5293402 (1994-03-01), Crespo et al.
patent: 5295159 (1994-03-01), Kerpez
patent: 5331670 (1994-07-01), Sorbara et al.
patent: 5337348 (1994-08-01), Yamazaki et al.
patent: 5339355 (1994-08-01), Mori et al.
patent: 5341474 (1994-08-01), Gelman et al.
patent: 5345437 (1994-09-01), Ogawa
patent: 5367540 (1994-11-01), Kakuishi et al.
patent: 5371532 (1994-12-01), Gelman et al.
patent: 5379441 (1995-01-01), Watanabe et al.
patent: 5390239 (1995-02-01), Morris et al.
patent: 5400322 (1995-03-01), Hunt et al.
patent: 5404388 (1995-04-01), Eu
patent: 5408260 (1995-04-01), Arnon
patent: 5408522 (1995-04-01), Ikehata et al.
patent: 5408614 (1995-04-01), Thornton et al.
patent: 5410264 (1995-04-01), Lechleider
patent: 5410343 (1995-04-01), Coddington et al.
patent: 5414455 (1995-05-01), Hooper et al.
patent: 5414733 (1995-05-01), Turner
patent: 5422876 (1995-06-01), Turudic
patent: 5428608 (1995-06-01), Freeman et al.
patent: 5430793 (1995-07-01), Ueltzen et al.
patent: 5436803 (1995-07-01), Annis et al.
patent: 5440335 (1995-08-01), Beveridge
patent: 5442390 (1995-08-01), Hooper et al.
patent: 5453779 (1995-09-01), Dan et al.
patent: 5461415 (1995-10-01), Wolf et al.
patent: 5461616 (1995-10-01), Suzuki
patent: 5461640 (1995-10-01), Gatherer
patent: 5469495 (1995-11-01), Beveridge
patent: 5475735 (1995-12-01), Williams et al.
patent: 5477263 (1995-12-01), O'Callaghan et al.
patent: 5479447 (1995-12-01), Chow et al.
patent: 5485672 (1996-01-01), Carpenter et al.
patent: 5495483 (1996-02-01), Grube et al.
patent: 5504736 (1996-04-01), Cubbison, Jr.
patent: 5504753 (1996-04-01), Renger et al.
patent: 5506868 (1996-04-01), Cox et al.
patent: 5513251 (1996-04-01), Rochkind et al.
patent: 5528585 (1996-06-01), Cooley et al.
patent: 5536905 (1996-07-01), Redman et al.
patent: 5544008 (1996-08-01), Dimmick et al.
patent: 5546379 (1996-08-01), Thaweethai et al.
patent: 5555244 (1996-09-01), Gupta et al.
patent: 5574724 (1996-11-01), Bales et al.
patent: 5583872 (1996-12-01), Albrecht et al.
patent: 5598406 (1997-01-01), Albrecht et al.
patent: 5600712 (1997-02-01), Hanson et al.
patent: 5602902 (1997-02-01), Satterlund et al.
patent: 5621363 (1997-04-01), Ogden et al.
patent: 5631897 (1997-05-01), Pacheco et al.
patent: 5632021 (1997-05-01), Jennings et al.
patent: 5649001 (1997-07-01), Thomas et al.
patent: 5668857 (1997-09-01), McHale
patent: 5678004 (1997-10-01), Thaweethai
patent: 5687176 (1997-11-01), Wisniewski et al.
patent: 5698818 (1997-12-01), Brench
patent: 5737364 (1998-04-01), Cohen et al.
patent: 5751710 (1998-05-01), Crowther et al.
patent: 5756280 (1998-05-01), Soora et al.
patent: 5770950 (1998-06-01), Zurcher et al.
patent: 5781617 (1998-07-01), McHale et al.
patent: 5793987 (1998-08-01), Quackenbush et al.
patent: 5796578 (1998-08-01), Jones
patent: 5799017 (1998-08-01), Gupta et al.
patent: 5812786 (1998-09-01), Seazholtz et al.
patent: 5852655 (1998-12-01), McHale et al.
patent: 5981103 (1999-11-01), Batten, Jr. et al.
patent: 62-084646 (1987-04-01), None
patent: 62-222755 (1987-09-01), None
patent: 63-76648 (1988-04-01), None
patent: 02271763 (1990-11-01), None
patent: 04100367 (1992-04-01), None
patent: WO 86/02796 (1986-05-01), None
patent: WO 97/37458 (1997-10-01), None
Horst Hessenm{umlaut over (u)}ller, et al., Zugangsnetzstrukturen f{umlaut over (u)}r interaktive Videodienste (Teil 1),Fernmelde Ingenieur, Der, vol. 48, No. 8, XP000647017, Aug., 1994, Germany, pp. 1-32 (with English translation).
Horst Hessenm{umlaut over (u)}ller, et al., Zugangsnetzstrukturen f{umlaut over (u)}r interaktive Videodienste (Teil 2),Fernmelde-Ingenieur, vol. 48, No. 9, XP000619688, Sep., 1994, Germany, pp. 1-28 (with English translation).
Baker & Botts L.L.P.
Cisco Technology Inc.
Gandhi Jayprakash N.
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