WO2003028424A1 - Shielding method and device - Google Patents

Shielding method and device Download PDF

Info

Publication number
WO2003028424A1
WO2003028424A1 PCT/NO2002/000312 NO0200312W WO03028424A1 WO 2003028424 A1 WO2003028424 A1 WO 2003028424A1 NO 0200312 W NO0200312 W NO 0200312W WO 03028424 A1 WO03028424 A1 WO 03028424A1
Authority
WO
WIPO (PCT)
Prior art keywords
carbon fibre
fibre material
casing
pad
shielding
Prior art date
Application number
PCT/NO2002/000312
Other languages
French (fr)
Inventor
Carl Erik Starefoss
Original Assignee
Pe-Development As
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Pe-Development As filed Critical Pe-Development As
Publication of WO2003028424A1 publication Critical patent/WO2003028424A1/en

Links

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q1/00—Details of, or arrangements associated with, antennas
    • H01Q1/12—Supports; Mounting means
    • H01Q1/22—Supports; Mounting means by structural association with other equipment or articles
    • H01Q1/24—Supports; Mounting means by structural association with other equipment or articles with receiving set
    • H01Q1/241—Supports; Mounting means by structural association with other equipment or articles with receiving set used in mobile communications, e.g. GSM
    • H01Q1/242—Supports; Mounting means by structural association with other equipment or articles with receiving set used in mobile communications, e.g. GSM specially adapted for hand-held use
    • H01Q1/245—Supports; Mounting means by structural association with other equipment or articles with receiving set used in mobile communications, e.g. GSM specially adapted for hand-held use with means for shaping the antenna pattern, e.g. in order to protect user against rf exposure
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q1/00—Details of, or arrangements associated with, antennas
    • H01Q1/52—Means for reducing coupling between antennas; Means for reducing coupling between an antenna and another structure
    • H01Q1/526—Electromagnetic shields
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q17/00—Devices for absorbing waves radiated from an antenna; Combinations of such devices with active antenna elements or systems
    • H01Q17/001—Devices for absorbing waves radiated from an antenna; Combinations of such devices with active antenna elements or systems for modifying the directional characteristic of an aerial
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B1/00—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
    • H04B1/38—Transceivers, i.e. devices in which transmitter and receiver form a structural unit and in which at least one part is used for functions of transmitting and receiving
    • H04B1/3827—Portable transceivers
    • H04B1/3833—Hand-held transceivers
    • H04B1/3838—Arrangements for reducing RF exposure to the user, e.g. by changing the shape of the transceiver while in use

Definitions

  • the presented invention concerns shielding of electromagnetic radiation from mobile phones or other handheld devices with a transmitter/receiver.
  • the electronic circuitry, processor and battery-generated electricity in the mobile phone all generate a low-frequency magnetic field which it is also desirable to protect the user against.
  • the purpose of the presented invention is to provide effective protection against hazardous electromagnetic radiation from mobile phones and other handheld telecommunication equipment. Not only against the RF-radiation that is used for the communication between the mobile phone and the base station, but also against the low-frequency magnetic fields mentioned above. At the same time, this protection shall not have any negative effects on the sound quality, communication sig- nals or battery capacity.
  • the purpose of the invention is achieved through inserting a pad consisting of a muitiaxial carbon fibre material in the phone's casing in such a way that the user is protected while using the handheld equipment.
  • the carbon fibre material can be attached to the inside of the casing and a lattice structure of metal, for example iron or aluminium, can then be arranged on each side of the carbon fibre material to provide further protection as well as to strengthen the protective pad.
  • a metal foil, made from e.g. aluminium, on the outside of the lattice structure will contribute to increased reflective properties and in this way provide further protection from the electromagnetic fields from the phone while also providing 'grounding' of the pad. This may vary from phone to phone.
  • the carbon fibre material can be a muitiaxial carbon fibre product of the type Devoid AMT, where the fibre structure consists of three layers of fibre and where each parallel layer of fibre is at a 45° angle to the underlying layer.
  • the fibre structure of the material also has the added effect of making the sound heard by the user, more pleasant.
  • This protective pad can in its design be moulded into the casing when the casing is produced or inserted by the user in the area of the phone that is closest to the user's ear during normal use of the device.
  • Figure 1 is a sketch showing an example of the outer casing of a mobile phone seen from the front;
  • Figure 2 is a basic outline of a Devoid AMT carbon fibre material with a muitiaxial fibre reinforcement structure;
  • Figure 3 is a drawing of a casing seen from the side with a carbon fibre pad that protects against electromagnetic radiation (the pad is shown in each of its basic components) according to an embodiment of the invention;
  • Figure 4 shows the various elements of the carbon fibre "pad” from Figure 3;
  • Figure 5 shows the front casing of a mobile phone seen from behind with the inserted carbon fibre pad according to an embodiment of the invention;
  • Figure 6 shows the carbon fibre pad according to two embodiments of the invention, arranged in the casing of a mobile phone, where the fibre pad in one embodiment is not grounded and in another embodiment where the pad is longer and in contact with ground in the display area.
  • FIG 1 the front cover of a well known mobile phone is shown.
  • the cover has a key pad area as well as an area intended for the display with an overlying window for the protection of the display.
  • the display area is placed against the user's ear so that the user of the mobile phone can communicate with the other party.
  • the mobile phones shown in figure 1 have an antenna construction in the display area.
  • the main part of the antenna is built into the device and usually with a small visible antenna protruding from the casing in this area.
  • the communication signals are therefore transmitted from the area of the phone which is closest to the head, and especially the ear, during use.
  • a carbon fibre material produced by Devoid AMT has proved itself suitable for the shielding of RF-radiation from mobile phones.
  • This well-known carbon fibre material shown in figure 2 consists of several layers of carbon fibre structures that form a pad. To give a few examples, such carbon fibre pads are used as reinforcement material in the hull of high-speed vessels as well as other constructions that have to be light but at the same time place great demands on strength.
  • the carbon fibre pad consists of several layers of carbon fibres that are placed at a 45° angle to the subsequent layer.
  • the pad that is used for the shielding of radiation according to the invention is a carbon fibre material with muitiaxial fibre reinforcement structure. This structure has preferably 3 layers, where the longitudinal weaving structure is arranged at an angle of 45°, 90° and 45° in relation to each other as it appears from figure 2. The mat both absorbs and reflects.
  • figure 1 it is also shown a carbon fibre pad/mat designed to be arranged on the back of the front casing of the mobile phone. This front casing is also shown from the side.
  • a lattice structure/grid of metal on each side of the pad together with a metal foil.
  • the layers are then organised in the following order: metal foil-lattice/grid-carbon fibre material-lattice/grid-metal foil.
  • the lattice/grid can be of either iron or aluminium, while the metal foil e.g. could be aluminium.
  • the lat- tice structure provides enhanced absorption of the electromagnetic radiation while also strengthening the structure.
  • the metal foil provides increased reflectivity.
  • the metal foil has an opening in the area of the loudspeaker in the mobile phone is placed so as not to affect the sound quality.
  • the carbon fibre material enables the sound to pass through. Tests have shown the SAR value for a mobile phone is reduced from 0.75 to 0.05 with the use of the protective pad according to the invention. The electromagnetic radiation that the user is exposed to is thereby almost reduced to zero.
  • the carbon fibre material is arranged in relation to the front casing of the mobile phone as shown in figure 1. It will then shield against radiation from the mobile phone towards the head by absorbing and grounding of the RF-radiation. The antenna construction will not be shielded in the direction facing away from the head. The telecommunication signals will therefore not be adversely affected as is the case with existing protective devices.
  • FIG 5 an embodiment of the protective pad is shown which covers the antenna area of the mobile phone and is connected to the metal casing that surrounds the mobile phone's display. Through this contact with the metal, the pad is connected to the ground plane in the phone.
  • Figure 5 also shows that the metal foil does not cover the speaker in the phone. How the size and shape of the foil is adapted in order to respectively ground/not ground the carbon fibre pad is also shown in figure 6.
  • Other mobile phones, e.g. GPRS phones, may have other placings of this ground plane.
  • the carbon fibre pad structure that protects against the electromagnetic radiation can easily be adapted according to each mobile phone's solution regarding the ground plane.
  • the carbon fibre pad can be shaped according to measurements and so the pro- tective pads can be adapted to each individual phone, and could be sold as an accessory.
  • the protective pads can then easily be installed, e.g. through the use of glue, two-sided adhesive tape or other methods of attachment, on the inside of the mobile phone casing by the user himself.
  • an additional version could have attached a prism-shaped RF- lens behind the carbon fibre pad and facing the antenna apparatus of the mobile phone. This will help to further deflect the RF-radiation away from the user's head and also strengthen the RF communication signals.
  • a reflective foil/metal grid can also be attached behind/in front of the carbon fibre pad between the casing and the interior electronics of the phone. This will then contribute to further reducing the radiation that the user is exposed to through the use of the phone during communication modus.
  • the carbon fibre material and possibly also the reflective foil can be laminated into the plastic in the casing during the production of this, and in this way achieve a built-in shielding of the mobile phone.
  • casings can be purchased as an extra/accessory in the same way that one today can purchase casings with different designs and colors. The casings can then cover all or parts of the mobile phone.
  • the carbon fibre pad also has an effect in shielding the low-frequency magnetic field from the circuit card.
  • the pad is light and thereby well suited for use in mobile phones, which today are light and small constructions. Experiments have also shown that the speech heard by the user becomes softer and more comfortable and that the sound level is not materially affected by the pad.
  • the carbon fibre structure can be used for shielding of electromagnetic radiation from mobile phones that have external antennae.

Landscapes

  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Telephone Set Structure (AREA)
  • Shielding Devices Or Components To Electric Or Magnetic Fields (AREA)

Abstract

The present invention concerns shielding of electromagnetic radiation from mobile phones or other handheld devices with transmitter/receiver. A special carbon fibre pad is used which is arranged in the mobile phone's casing.

Description

SHIELDING METHOD AND DEVICE
INTRODUCTION
The presented invention concerns shielding of electromagnetic radiation from mobile phones or other handheld devices with a transmitter/receiver.
BACKGROUND
Mobile phones are today an integrated part of modern telecommunication equip- ment and an increasing number of people use such equipment daily. However, there exists a great deal of uncertainty regarding whether the electromagnetic fields surrounding the mobile phone antenna can be harmful to the user. When voice communication is conducted through handheld telecommunication equipment such as mobile phones, the equipment is held against the ear as a normal telephone. This telecommunication device uses microwave signals with a frequency in the range of 1800-1900 MHz. Electromagnetic radiation in this frequency range can affect a human being and result in increased temperatures in local areas of the brain. Such fields represent a potential long-term health risk to the user. It is therefore important to minimise this risk through, to the greatest extent possible, shielding the user from the electromagnetic radiation. Typical SAR values (Specific Absorption Rates) for normal mobile telephones are in the range of 0.75 to 1.64.
While wanting to minimise the amount of RF-radiation that the user's head is expo- sed to, it is important for the mobile phones to still be able to communicate with the base stations. Currently, procedures exists whereby mobile phones are shielded through the use of protective elements on the outside of the phone. However, these procedures result in a weakening of the telecommunication signals used to communicate with the base stations and as a result only the closest base stations can be reached. When the signals become weaker the phone increases the power at which the signals are transmitted with the result that the batteries are rapidly depleted. When the drawing of current from the battery increases, the low-frequency magnetic field also increases, resulting in a heating up of the phone. This is also seen as a negative side-effect. In addition to this, the RF-radiation leaks through non-isolated components. Another negative side-effect is the fact that the sound becomes metallic and weak.
The electronic circuitry, processor and battery-generated electricity in the mobile phone all generate a low-frequency magnetic field which it is also desirable to protect the user against.
The purpose of the presented invention is to provide effective protection against hazardous electromagnetic radiation from mobile phones and other handheld telecommunication equipment. Not only against the RF-radiation that is used for the communication between the mobile phone and the base station, but also against the low-frequency magnetic fields mentioned above. At the same time, this protection shall not have any negative effects on the sound quality, communication sig- nals or battery capacity.
SUMMARY OF THE INVENTION
The purpose of the invention is achieved through inserting a pad consisting of a muitiaxial carbon fibre material in the phone's casing in such a way that the user is protected while using the handheld equipment. In this design, the carbon fibre material can be attached to the inside of the casing and a lattice structure of metal, for example iron or aluminium, can then be arranged on each side of the carbon fibre material to provide further protection as well as to strengthen the protective pad. A metal foil, made from e.g. aluminium, on the outside of the lattice structure will contribute to increased reflective properties and in this way provide further protection from the electromagnetic fields from the phone while also providing 'grounding' of the pad. This may vary from phone to phone.
The carbon fibre material can be a muitiaxial carbon fibre product of the type Devoid AMT, where the fibre structure consists of three layers of fibre and where each parallel layer of fibre is at a 45° angle to the underlying layer. The fibre structure of the material also has the added effect of making the sound heard by the user, more pleasant. This protective pad can in its design be moulded into the casing when the casing is produced or inserted by the user in the area of the phone that is closest to the user's ear during normal use of the device.
The invention is defined in the appending claims.
SHORT DESCRIPTION OF DRAWINGS Embodiments of the invention will be described based on the attached drawings where:
Figure 1 is a sketch showing an example of the outer casing of a mobile phone seen from the front; Figure 2 is a basic outline of a Devoid AMT carbon fibre material with a muitiaxial fibre reinforcement structure;
Figure 3 is a drawing of a casing seen from the side with a carbon fibre pad that protects against electromagnetic radiation (the pad is shown in each of its basic components) according to an embodiment of the invention; Figure 4 shows the various elements of the carbon fibre "pad" from Figure 3; Figure 5 shows the front casing of a mobile phone seen from behind with the inserted carbon fibre pad according to an embodiment of the invention; and Figure 6 shows the carbon fibre pad according to two embodiments of the invention, arranged in the casing of a mobile phone, where the fibre pad in one embodiment is not grounded and in another embodiment where the pad is longer and in contact with ground in the display area.
DETAILED DESCRIPTION
In figure 1 the front cover of a well known mobile phone is shown. The cover has a key pad area as well as an area intended for the display with an overlying window for the protection of the display. During use the display area is placed against the user's ear so that the user of the mobile phone can communicate with the other party. The mobile phones shown in figure 1 have an antenna construction in the display area. The main part of the antenna is built into the device and usually with a small visible antenna protruding from the casing in this area. The communication signals are therefore transmitted from the area of the phone which is closest to the head, and especially the ear, during use.
Surprisingly, a carbon fibre material produced by Devoid AMT has proved itself suitable for the shielding of RF-radiation from mobile phones. This well-known carbon fibre material shown in figure 2, consists of several layers of carbon fibre structures that form a pad. To give a few examples, such carbon fibre pads are used as reinforcement material in the hull of high-speed vessels as well as other constructions that have to be light but at the same time place great demands on strength. As can be seen from figure 2 the carbon fibre pad consists of several layers of carbon fibres that are placed at a 45° angle to the subsequent layer. The pad that is used for the shielding of radiation according to the invention is a carbon fibre material with muitiaxial fibre reinforcement structure. This structure has preferably 3 layers, where the longitudinal weaving structure is arranged at an angle of 45°, 90° and 45° in relation to each other as it appears from figure 2. The mat both absorbs and reflects.
In figure 1 it is also shown a carbon fibre pad/mat designed to be arranged on the back of the front casing of the mobile phone. This front casing is also shown from the side.
As it appears from figure 3 it is in a preferred embodiment, in addition to the carbon fibre pad, also arranged a lattice structure/grid of metal on each side of the pad together with a metal foil. The layers are then organised in the following order: metal foil-lattice/grid-carbon fibre material-lattice/grid-metal foil. The lattice/grid can be of either iron or aluminium, while the metal foil e.g. could be aluminium. The lat- tice structure provides enhanced absorption of the electromagnetic radiation while also strengthening the structure. The metal foil provides increased reflectivity. These elements are also shown in figure 4. In this figure it can also be seen that the metal foil has an opening in the area of the loudspeaker in the mobile phone is placed so as not to affect the sound quality. The carbon fibre material enables the sound to pass through. Tests have shown the SAR value for a mobile phone is reduced from 0.75 to 0.05 with the use of the protective pad according to the invention. The electromagnetic radiation that the user is exposed to is thereby almost reduced to zero.
The carbon fibre material is arranged in relation to the front casing of the mobile phone as shown in figure 1. It will then shield against radiation from the mobile phone towards the head by absorbing and grounding of the RF-radiation. The antenna construction will not be shielded in the direction facing away from the head. The telecommunication signals will therefore not be adversely affected as is the case with existing protective devices.
In figure 5 an embodiment of the protective pad is shown which covers the antenna area of the mobile phone and is connected to the metal casing that surrounds the mobile phone's display. Through this contact with the metal, the pad is connected to the ground plane in the phone. Figure 5 also shows that the metal foil does not cover the speaker in the phone. How the size and shape of the foil is adapted in order to respectively ground/not ground the carbon fibre pad is also shown in figure 6. Other mobile phones, e.g. GPRS phones, may have other placings of this ground plane. The carbon fibre pad structure that protects against the electromagnetic radiation can easily be adapted according to each mobile phone's solution regarding the ground plane.
The carbon fibre pad can be shaped according to measurements and so the pro- tective pads can be adapted to each individual phone, and could be sold as an accessory. The protective pads can then easily be installed, e.g. through the use of glue, two-sided adhesive tape or other methods of attachment, on the inside of the mobile phone casing by the user himself.
To further increase the protection of the user against the electromagnetic fields from the antenna, an additional version could have attached a prism-shaped RF- lens behind the carbon fibre pad and facing the antenna apparatus of the mobile phone. This will help to further deflect the RF-radiation away from the user's head and also strengthen the RF communication signals. A reflective foil/metal grid can also be attached behind/in front of the carbon fibre pad between the casing and the interior electronics of the phone. This will then contribute to further reducing the radiation that the user is exposed to through the use of the phone during communication modus.
The carbon fibre material and possibly also the reflective foil can be laminated into the plastic in the casing during the production of this, and in this way achieve a built-in shielding of the mobile phone. One can also imagine that such casings can be purchased as an extra/accessory in the same way that one today can purchase casings with different designs and colors. The casings can then cover all or parts of the mobile phone.
The carbon fibre pad also has an effect in shielding the low-frequency magnetic field from the circuit card. Through manufacturing entire front casings or separate protective units for attachment to the inside of the casings, effective protection of the user against both the fields from the antenna and the rest of the phone, is achieved.
In addition to the fact that the carbon fibre pad has exhibited surprisingly good shielding properties against the electromagnetic fields that are exploited in the present invention, the pad is light and thereby well suited for use in mobile phones, which today are light and small constructions. Experiments have also shown that the speech heard by the user becomes softer and more comfortable and that the sound level is not materially affected by the pad.
It is also possible that the carbon fibre structure can be used for shielding of electromagnetic radiation from mobile phones that have external antennae. One could then envisage a solution where e.g. a flip lid of a mobile phone can be pushed up between the antenna and the user and achieve the desired protection.
Embodiments of the invention have now been described. It will be evident for a person skilled in the art that other embodiments of the invention can be used and the invention is therefore only limited by the appended claims.

Claims

1. Method for shielding of electromagnetic fields from handheld devices with transmitter/receiver such as e.g. mobile phones, characterised in arranging a pad comprising a muitiaxial carbon fibre material in the casing of the device, in such a way that shielding of the user during use of the handheld device is achieved.
2. Method according to claim 1 , characterized in arranging the carbon fibre on the inside of the casing.
3. Method according to claim 1 , characterized in arranging a metal lattice structure adjacent both sides of the carbon fibre material.
4. Method according to claim 3, characterized in arranging a metal foil to the outside of the lattice structure.
5. Method according to claim 1 , characterized in moulding the pad comprising the carbon fibre material into the casing during production of this.
6. Method according to claim 1, characterized in that the carbon fibre material is arranged in the area of the casing closest to the user's ear during voice communication via the handheld device.
7. Method according to claim 3, characterized in that the metal foil is iron or aluminium.
8. Method according to claim 1 , characterized in that the carbon fibre material is a muitiaxial carbon fibre product of the type Devoid AMT.
9. Device for shielding of electromagnetic fields from handheld devices with transmitter/receiver, characterized in that the shielding device comprises a muitiaxial carbon fibre material arranged in the device, where the carbon fibre material is built up of several unidirectional fibre layers.
10. Device according to claim 9, characterized in that it further comprises a metal grid structure arranged adjacent each side of the carbon fibre material.
11. Device according to claim 10, characterized in that it comprises a metal foil arranged adjacent the grid structures on the outside of these.
12. Device according to claim 10, characterized in that the lattice structure/grid is made from iron or aluminium.
13. Device according to claim 11 , characterized in that the metal foil is made from aluminium.
14. Device according to claim 9, characterized in that the carbon fibre material is of the type Devoid AMT.
15. Use of a muitiaxial carbon fibre material to shield a user of a handheld device with a transmitter/receiver, such as e.g. a mobile phone, from health damaging electromagnetic fields generated by the device.
16. Use according to claim 15, characterized in that the muitiaxial carbon fibre material is of the type Devoid AMT.
PCT/NO2002/000312 2001-09-07 2002-09-06 Shielding method and device WO2003028424A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
NO20014376 2001-09-07
NO20014376A NO20014376L (en) 2001-09-07 2001-09-07 Method and apparatus for shielding from electromagnetic fields

Publications (1)

Publication Number Publication Date
WO2003028424A1 true WO2003028424A1 (en) 2003-04-03

Family

ID=19912813

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/NO2002/000312 WO2003028424A1 (en) 2001-09-07 2002-09-06 Shielding method and device

Country Status (2)

Country Link
NO (1) NO20014376L (en)
WO (1) WO2003028424A1 (en)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8208980B2 (en) 2008-11-06 2012-06-26 Pong Research Corporation Radiation redirecting external case for portable communication device and antenna embedded in battery of portable communication device
US8214003B2 (en) 2009-03-13 2012-07-03 Pong Research Corporation RF radiation redirection away from portable communication device user
US8957813B2 (en) 2009-03-13 2015-02-17 Pong Research Corporation External case for redistribution of RF radiation away from wireless communication device user and wireless communication device incorporating RF radiation redistribution elements
US9172134B2 (en) 2008-11-06 2015-10-27 Antenna79, Inc. Protective cover for a wireless device
DE102015110771A1 (en) * 2015-07-03 2017-01-05 BDM Innovative GmbH Device for shielding and converting the energy of an electromagnetic field
US9838060B2 (en) 2011-11-02 2017-12-05 Antenna79, Inc. Protective cover for a wireless device
WO2021152477A1 (en) * 2020-01-27 2021-08-05 Tibani Beheer B.V. Device for protection against electromagnetic radiation

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2240782A (en) * 1990-02-13 1991-08-14 Kitagawa Ind Co Ltd Housing material for a portable communication device
US5394149A (en) * 1991-05-28 1995-02-28 Osaka Gas Company Limited Method of absorbing electromagnetic waves
US5399295A (en) * 1984-06-11 1995-03-21 The Dow Chemical Company EMI shielding composites
US5444866A (en) * 1993-02-24 1995-08-22 Cykiert; Robert C. Device for shielding a cellular telephone user from electromagnetic waves
US5657386A (en) * 1995-09-06 1997-08-12 Schwanke; Jurgen H. Electromagnetic shield for cellular telephone
US6200630B1 (en) * 1996-03-13 2001-03-13 Telefonaktiebolaget Lm Ericsson Producing a metallic layer on the surface of a detail for shielding against electromagnetic radiation
US6219419B1 (en) * 1998-05-27 2001-04-17 Asiatic Fiber Corporation Sticker shielding against electromagnetic wave

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5399295A (en) * 1984-06-11 1995-03-21 The Dow Chemical Company EMI shielding composites
GB2240782A (en) * 1990-02-13 1991-08-14 Kitagawa Ind Co Ltd Housing material for a portable communication device
US5394149A (en) * 1991-05-28 1995-02-28 Osaka Gas Company Limited Method of absorbing electromagnetic waves
US5444866A (en) * 1993-02-24 1995-08-22 Cykiert; Robert C. Device for shielding a cellular telephone user from electromagnetic waves
US5657386A (en) * 1995-09-06 1997-08-12 Schwanke; Jurgen H. Electromagnetic shield for cellular telephone
US6200630B1 (en) * 1996-03-13 2001-03-13 Telefonaktiebolaget Lm Ericsson Producing a metallic layer on the surface of a detail for shielding against electromagnetic radiation
US6219419B1 (en) * 1998-05-27 2001-04-17 Asiatic Fiber Corporation Sticker shielding against electromagnetic wave

Cited By (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US9112584B2 (en) 2008-11-06 2015-08-18 Antenna79, Inc. External case for redistribution of RF radiation away from wireless communication device user and wireless communication device incorporating RF radiation redistribution elements
US9287915B2 (en) 2008-11-06 2016-03-15 Antenna79, Inc. Radiation redirecting elements for portable communication device
US8442602B2 (en) 2008-11-06 2013-05-14 Pong Research Corporation Radiation redirecting external case for portable communication device and antenna embedded in battery of portable communication device
US8750948B2 (en) 2008-11-06 2014-06-10 Pong Research Corporation Radiation redirecting elements for portable communication device
US8897843B2 (en) 2008-11-06 2014-11-25 Pong Reseach Corporation RF radiation redirection away from portable communication device user
US9472841B2 (en) 2008-11-06 2016-10-18 Antenna79, Inc. RF radiation redirection away from portable communication device user
US9350410B2 (en) 2008-11-06 2016-05-24 Antenna79, Inc. Protective cover for a wireless device
US9172134B2 (en) 2008-11-06 2015-10-27 Antenna79, Inc. Protective cover for a wireless device
US8208980B2 (en) 2008-11-06 2012-06-26 Pong Research Corporation Radiation redirecting external case for portable communication device and antenna embedded in battery of portable communication device
US8214003B2 (en) 2009-03-13 2012-07-03 Pong Research Corporation RF radiation redirection away from portable communication device user
US8957813B2 (en) 2009-03-13 2015-02-17 Pong Research Corporation External case for redistribution of RF radiation away from wireless communication device user and wireless communication device incorporating RF radiation redistribution elements
US9838060B2 (en) 2011-11-02 2017-12-05 Antenna79, Inc. Protective cover for a wireless device
DE102015110771A1 (en) * 2015-07-03 2017-01-05 BDM Innovative GmbH Device for shielding and converting the energy of an electromagnetic field
WO2021152477A1 (en) * 2020-01-27 2021-08-05 Tibani Beheer B.V. Device for protection against electromagnetic radiation
NL2024762B1 (en) * 2020-01-27 2021-09-09 Tibani Beheer B V DEVICE FOR PROTECTION AGAINST ELECTROMAGNETIC RADIATION

Also Published As

Publication number Publication date
NO20014376D0 (en) 2001-09-07
NO20014376L (en) 2003-03-10

Similar Documents

Publication Publication Date Title
US20020009976A1 (en) Radiation protection device for cellular telephones
EP0688478B1 (en) Accessory for a mobile communication device
US5657386A (en) Electromagnetic shield for cellular telephone
KR100782512B1 (en) Mobile terminal for improving specification absorption rate
US20050090299A1 (en) Mobile phone capable of reducing an electromagnetic specific absorption rate in human bodies
US20020137475A1 (en) Anti electromagnetic wave box for a mobile phone
AU721616B2 (en) A shielding device
US7099631B2 (en) Mobile phone having reduced specific absorption rate (SAR) using an antenna housed to ensure enhanced antenna gain
US6448490B1 (en) Assembly for attenuating emissions from electronic sources
CA2139682A1 (en) Radiation reduction apparatus for a portable radio communication device
CA2325112A1 (en) Portable radio communication device, such as a portable telephone
KR101200051B1 (en) Film for shielding electromagnetic wave of mobile phone
WO2003028424A1 (en) Shielding method and device
US6404403B1 (en) Radio frequency radiation shield unit for wireless telephones
US20200328770A1 (en) Anti-radiation mobile phone case
WO1994021053A1 (en) Antenna fixture for hand-held cellular telephones
EP1393408A1 (en) Safety shield
EP0915572A1 (en) Shielding system for mobile and radio telephones
GB2330726A (en) Radiation shielding case for mobile and radio telephones.
WO2008067570A2 (en) Screened wireless telephone device and method
KR101177361B1 (en) Panel for shielding electromagnetic wave of mobile phone
WO1999044346A1 (en) Reducing radiation in hand held cellular telephones and other mobile communication
CN210609322U (en) Mobile phone casing
CN209881877U (en) Mobile phone cover
JPH10308595A (en) Portable telephone case for cutting off radio wave

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): AE AG AL AM AT AU AZ BA BB BG BY BZ CA CH CN CO CR CU CZ DE DM DZ EC EE ES FI GB GD GE GH HR HU ID IL IN IS JP KE KG KP KR LC LK LR LS LT LU LV MA MD MG MN MW MX MZ NO NZ OM PH PL PT RU SD SE SG SI SK SL TJ TM TN TR TZ UA UG US UZ VC VN YU ZA ZM

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): GH GM KE LS MW MZ SD SL SZ UG ZM ZW AM AZ BY KG KZ RU TJ TM AT BE BG CH CY CZ DK EE ES FI FR GB GR IE IT LU MC PT SE SK TR BF BJ CF CG CI GA GN GQ GW ML MR NE SN TD TG

121 Ep: the epo has been informed by wipo that ep was designated in this application
122 Ep: pct application non-entry in european phase
NENP Non-entry into the national phase

Ref country code: JP

WWW Wipo information: withdrawn in national office

Country of ref document: JP