US-12628324-B2 - Flexible electromagnetic shielding that attenuates electromagnetic interference

US12628324B2US 12628324 B2US12628324 B2US 12628324B2US-12628324-B2

Abstract

Described herein is electromagnetic shielding that is configured to attenuate electromagnetic interference (EMI) by at least a threshold amount when the EMI has a frequency within a predefined frequency range. The electromagnetic shielding includes a layer of metal, such as aluminum foil, and a layer of thermoplastic polymer fabric (such as woven polyethylene fabric), where the electromagnetic shielding has several apertures that extend therethrough. The electromagnetic shielding is at least partially draped over electronic equipment that is to be shielded from EMI.

Inventors

Jesse William Sanders

Assignees

MICROSOFT TECHNOLOGY LICENSING, LLC

Dates

Publication Date: 20260512
Application Date: 20240222

Claims (20)

1 . A data center comprising: a piece of electronic equipment; and electromagnetic shielding that is draped over the piece of electronic equipment to attenuate electromagnetic interference (EMI) within a frequency range by a threshold amount, where the electromagnetic shielding comprises: a layer of metal; a layer of thermoplastic polymer fabric that is bonded to the layer of metal, where the layer of thermoplastic polymer fabric provides a structural backing for the layer of metal; a second layer of metal, where the layer of thermoplastic polymer fabric is positioned between the layer of metal and the second layer of metal, and further where the second layer of metal is bonded to the layer of thermoplastic polymer fabric; and apertures that extend through a thickness of the electromagnetic shielding, wherein the apertures are perforations that extend through the layer of metal, the layer of thermoplastic polymer fabric, and the second layer of metal.
2 . The data center of claim 1 , where the electromagnetic shielding additionally comprises an adhesive placed between the layer of metal and the layer of thermoplastic polymer, where the adhesive bonds the layer of metal to the layer of thermoplastic polymer fabric.
3 . The data center of claim 1 , where the electromagnetic shielding further comprises: a second layer of thermoplastic polymer fabric, where the second layer of metal is positioned between the layer of thermoplastic polymer fabric and the second layer of thermoplastic polymer fabric, the second layer of thermoplastic polymer fabric is bonded to the second layer of metal, and further where the apertures extend through the second layer of thermoplastic polymer fabric.
4 . The data center of claim 3 , where the layer of thermoplastic polymer fabric and the second layer of thermoplastic polymer fabric are woven polyethylene fabric, and further where each of the layer of thermoplastic polymer fabric and the second layer of thermoplastic polymer fabric has a thickness of between 1 millimeter and 10 millimeters.
5 . The data center of claim 3 , where the apertures have a hexagonal cross section.
6 . The data center of claim 5 , where the apertures are arranged to form a honeycomb pattern.
7 . The data center of claim 3 , where each aperture in the apertures has a major diameter of between 4 millimeters and 15 millimeters.
8 . The data center of claim 3 , where the thickness of the electromagnetic shielding is between 10 millimeters and 26 millimeters.
9 . The data center of claim 1 , where the layer of metal and the second layer of metal are formed of aluminum, and further where each of the layer of metal and the second layer of metal has a thickness of between 0.01 millimeter and 10 millimeters.
10 . The data center of claim 1 , further comprising a support mechanism that is positioned above the piece of electronic equipment, where the electromagnetic shielding is supported by the support mechanism when the electromagnetic shielding is draped over the piece of electronic equipment.
11 . The data center of claim 10 , where the support mechanism comprises a non-conductive plate that is hung from a ceiling above the piece of electronic equipment.
12 . The data center of claim 1 , further comprising a support that is supported by a floor upon which the piece of electronic equipment rests, where the support supports the electromagnetic shielding, and further where the support prevents the electromagnetic shielding from contacting the piece of electronic equipment.
13 . The data center of claim 1 , where the layer of thermoplastic polymer fabric is a paraffin fabric.
14 . The data center of claim 1 , where the frequency range is 9 kHz-24 GHz.
15 . The data center of claim 1 , where a major diameter of each of the apertures is approximately 6.4 millimeters.
16 . The data center of claim 1 , where the layer of metal forms an exterior surface of the electromagnetic shielding.
17 . The data center of claim 1 , where the layer of thermoplastic polymer fabric forms an exterior surface of the electromagnetic shielding.
18 . The data center of claim 1 , where the threshold amount is approximately-85 dB.
19 . A method comprising: positioning a piece of electronic equipment in a data center; and draping electromagnetic shielding over the piece of electronic equipment to attenuate electromagnetic interference (EMI) within a frequency range by a threshold amount, where the electromagnetic shielding comprises: a layer of metal; a layer of thermoplastic polymer fabric that is bonded to the layer of metal, where the layer of thermoplastic polymer fabric provides a structural backing for the layer of metal; a second layer of metal, where the layer of thermoplastic polymer fabric is positioned between the layer of metal and the second layer of metal, and further where the second layer of metal is bonded to the layer of thermoplastic polymer fabric; and apertures that extend through a thickness of the electromagnetic shielding, wherein the apertures are perforations that extend through the layer of metal, the layer of thermoplastic polymer fabric, and the second layer of metal.
20 . A method comprising: supporting electromagnetic shielding from a support mechanism that is coupled to a ceiling of a building that retains electronic equipment, where the electromagnetic shielding comprises: a layer of metal; a layer of thermoplastic polymer fabric that is bonded to the layer of metal, where the layer of thermoplastic polymer fabric provides a structural backing for the layer of metal; a second layer of metal, where the layer of thermoplastic polymer fabric is positioned between the layer of metal and the second layer of metal, and further where the second layer of metal is bonded to the layer of thermoplastic polymer fabric; and apertures that extend through a thickness of the electromagnetic shielding, wherein the apertures are perforations that extend through the layer of metal, the layer of thermoplastic polymer fabric, and the second layer of metal; and draping the electromagnetic shielding over a piece of the electronic equipment.

Description

RELATED APPLICATION This application is a continuation of U.S. patent application Ser. No. 17/827,701, filed on May 28, 2022, and entitled “FLEXIBLE ELECTROMAGNETIC SHIELDING THAT ATTENUATES ELECTROMAGNETIC INTERFERENCE”, the entirety of which is incorporated herein by reference. BACKGROUND As more and more data processing is undertaken at data centers, it is becoming increasingly important to secure electronic equipment from security breaches. An example security breach is a stand-off attack, where an attacker purposefully generates electromagnetic interference (EMI) in connection with controlling or disrupting operation of electronic equipment in the data center. To address such attacks, electromagnetic shielding can be used to shield the electronic equipment from EMI. A conventional approach for shielding electronic equipment of a data center from EMI is to shield an entire data center, where electromagnetic shielding is constructed along walls, electromagnetic shielding is placed over ductwork, and so forth. In another convention approach, electromagnetic shielding is applied to an entire room of the data center where critical electronic equipment is positioned. For example, to shield an entire data center, walls of the data center are lined with nonmagnetic layers of metal and rigid honeycomb waveguides are affixed to vent openings. Further, specially designed doors that are configured to attenuate EMI are employed. As can be ascertained from the foregoing, shielding an entire data center is a labor-intensive and expensive process. More recently, special-purpose electromagnetic shielding enclosures that are configured to shield racks of servers in data centers have been developed. These shielding enclosures are made of rigid walls and prevent EMI from exiting the enclosures or entering the enclosures. Such shielding enclosures, however, are often cost-prohibitive and render it difficult for maintenance technicians to access servers in these racks of servers for maintenance, replacement, and so forth. There is currently no relatively inexpensive electromagnetic shielding that allows for individual pieces of electronic equipment to be shielded from EMI while simultaneously allowing for relatively easy access to the electronic equipment for purposes of maintenance, replacement, etc. SUMMARY The following is a brief summary of subject matter that is described in greater detail herein. This summary is not intended to be limiting as to the scope of the claims. Described herein are various technologies pertaining to electromagnetic shielding, use of the electromagnetic shielding, and manufacture of the electromagnetic shielding. The electromagnetic shielding is configured to attenuate electromagnetic interference (EMI) by at least a threshold amount (e.g., between −70 and −90 dB) when the EMI has a frequency within a predefined frequency range (e.g., between 9 kHz and 24 GHz). In an example, the electromagnetic shielding described herein meets IEEE 299 standards. The electromagnetic shielding described herein is advantageous over conventional electromagnetic shielding used in data centers, in that the electromagnetic shielding described herein is configured to shield individually selected electrical devices or a group of selected electrical devices (e.g., a server computing device or a rack of server computing devices); in contrast, conventional approaches include shielding an entire data center or room in the data center. In addition, the electromagnetic shielding described herein is relatively inexpensive to manufacture and install. Still further, the electromagnetic shielding described herein allows for air to pass therethrough, such that cooling requirements for electrical devices in datacenters can be met while the electrical devices are shielded from EMI. Moreover, the electromagnetic shielding described herein can be readily moved, such that a maintenance technician can access electronic equipment that is shielded the electromagnetic shielding. The electromagnetic shielding described herein is flexible yet sufficiently sturdy to allow for repositioning and movement. The electromagnetic shielding includes a layer of metal (such as aluminum foil), a layer of thermoplastic polymer fabric (such as a woven polyethylene fabric), and an adhesive that bonds the layer of metal to the layer of thermoplastic polymer fabric. The electromagnetic shielding includes several apertures that extend therethrough (through the layer of metal and the layer of thermoplastic polymer fabric). The layer of thermoplastic polymer fabric provides a structural backing for the layer of metal, while the layer of metal and the apertures are configured to attenuate EMI by a threshold amount when the EMI has a frequency within a predefined frequency range. In an example, the apertures are hexagonal and are arranged in a honeycomb pattern, such that the electromagnetic shielding is a honeycomb waveguide. The major diameter of each apertu