GB2349747A - A clip-on electromagnetic shield for a mobile phone's antenna - Google Patents

A clip-on electromagnetic shield for a mobile phone's antenna Download PDF

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Publication number
GB2349747A
GB2349747A GB9910477A GB9910477A GB2349747A GB 2349747 A GB2349747 A GB 2349747A GB 9910477 A GB9910477 A GB 9910477A GB 9910477 A GB9910477 A GB 9910477A GB 2349747 A GB2349747 A GB 2349747A
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United Kingdom
Prior art keywords
sheet
aerial
radiation
telephone
copper
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Granted
Application number
GB9910477A
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GB9910477D0 (en
GB2349747B (en
Inventor
Wing Kei Wong
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Individual
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Individual
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Priority to GB9910477A priority Critical patent/GB2349747B/en
Publication of GB9910477D0 publication Critical patent/GB9910477D0/en
Publication of GB2349747A publication Critical patent/GB2349747A/en
Application granted granted Critical
Publication of GB2349747B publication Critical patent/GB2349747B/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

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Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q15/00—Devices for reflection, refraction, diffraction or polarisation of waves radiated from an antenna, e.g. quasi-optical devices
    • H01Q15/14—Reflecting surfaces; Equivalent structures
    • 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

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  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Telephone Set Structure (AREA)

Abstract

An electromagnetic shield 10 shields a mobile phone user's head from electromagnetic radiation emitted by the phone's antenna (50 fig 6). The shield is attached to the antenna by means of a clip 28. The shield is formed from a folded sheet 20. The material of the sheet may be metal (eg copper) and the metal may contain magnetic material. The shield may be painted and the paint may contain metallic powder (eg copper and/or aluminium). A metal stud 32 of brass is fitted to the upper end 34 of the shield 10. The shield 10 may be telescopic so as to screen the radiation emitted from a telescopic aerial.

Description

TITLE :"Anti-Radiation Device" FJELD OF THE INVENTION This invention relates to anti-radiation devices, more particularly for use in connection with mobile, cordless and other telephones and instruments having an aerial and adapted for use close to the head.
BACKGROUND TO THE INVENTION The present inventor is aware of concern, particularly with mobile telephones, which need to radiate a strong signal to communicate with a distant static station, that the amount of radiation produced is so great that it could be harmful to the user's brain.
A proposa is known to the present inventor to hood the mobile phone's aerial with a foam cap for this purpose, but this was ineffective.
TI-E INVENTION According to one aspect of the invention, there is provided an anti-radiation device which is adapted for mounting to a mobile or like telephone. This is adapted for mounting to a substantially cylindrical aerial of the telephone. Preferably, it is principally (more than 50% w/w) or substantially wholly made of electrically conductive material, e. g. metal. If the metal of the shield comprises pure copper, this has been found to give a reduction of 30% in the radiation past the shield, using a radiation detector probe with its tip 1 cm past the shield. The metal may comprise at least 50% copper w/w, more preferably at least 70% copper w/w. If the metal comprises at least 10% magnetic material w/w, e. g., iron, cobalt, nickel, the total reduction in radiation past the shield has been measured as 70%. The metal may comprise at least 10% other than copper and magnetic material w/w, e. g. other metals, and numerus random trials have on occasion produced as much as 90% total reduction in radiation past the shield, though the intention sometimes has only been to improve hardening and elasticity of the material.
'ne device is preferably substantially wholly in the form of sheet, with a thickness in the range of from 0. 1 to 0. 5 mm, varying, for example, according to the diameter of the aerial and the expected signal strength. If the sheet is provided with a coating of paint, this can produce a few % improvement in radiation reduction, especially if the paint comprises a metallic powder, e. g. comprising copper and/or aluminium, possibly magnetic material, and metallic material other than copper, aluminium and magnetic material. The coating may be applied like a laquer, and/or baked hard ; and several, e. g. 7, such laquer coatings may be applied. Preferably, the coating of paint has a thickness in the range of from 0. 1 to 0. 5 times the thickness of the sheet, more preferably a thickness of substantially a quarter that of the sheet, though the coating must not be too thick or it will noticeably decrease the quality of reception.
In a preferred embodiment, the sheet has a major part shaped to cover in the range of from a quarter to a half (preferably substantially 0. 4) of the circumference of a cylindrical aerial of the telephone (where"cover"means"be adapted to be interpose between the aerial and a transmitter/receiver"), and preferably has edge portions extending axially of the aerial which are interrupted to reduce the shielding effect of the sheet at those portions, the interruptions preferably being in the form of holes and/or slits.
The device may comprise a clip to fit it to a cylindrical aerial of the telephone, preferably folded down (preferably internally, which spaces the shield a little more from the aerial and is found to cut out a little more radiation) from a major shielding part of the sheet, and preferably interrupted to reduce its shielding effect on the static transmitter/receiver side of the aerial, i. e. opposite the head, since the clip will normally extend more than half way round the circumference of the aerial. A metal stud, preferably of brass, is fitted to one end of the device, preferably by welding.
This appears to have the effect of attracting or concentrating the incoming signal and/or outgoing signal, and has given a communication improvement of 10% in these signals in some trials. Preferably, said sheet is curved and/or bent and it comprises at least one information plate fitted inside and/or outside the sheet. This plate, when internal, may be provided with teeth that fit into the abovementioned holes to hold the plate to the remainder of the device, or may be welded to the latter.
The device has a size adapted to fit to a standard diameter cylindrical aerial of a mobile telephone, e. g. a 6, 8 or 10 mm diameter aerial.
The device may be adapted to cover a telescopic aerial of a telephone, e. g. the device being telescopic. In use, the preferred anti-radiation device is mounted to a stub aerial of a mobile or like telephone, so that the device has a major, part-cylindrical radiation-shielding portion arrange to be interpose between the aerial and the user's ear and extending the whole height of the aerial, and leaves the other side of the aerial as nearly as possible unshielded from the static transmitter/receiver so as to allow the maximum sensitivity of the phone for transmission and reception of signals. The clip is arrange at the root end of the stub aerial, and the stud at the remote/free end of the aerial.
The preferred device is made of a material, e. g. metal, produced from a mix of powders (e. g. copper and iron) heated to 500 degrees Celsius to produce a melt, which is rolled to a sheet as it cools and solidifies. This is then shaped and pierced, and then folded to shape. The folded-back clip may also be welded to the major part of the shield device.
Another aspect of the invention consists in a method of producing an anti-radiation device, in which at least a major radiation-shielding portion of the device is formed from a melted powder mix. Another aspect of the invention consists in a method producing an anti-radiation device, in which a plurality of metallic ingredients in powdered form on mixed well together and melted to produce a mix from which is formed at least a major radiation-shielding portion of the device. According to another aspect of the invention, a major radiation-shielding portion of an anti-radiation device is coated with a paint comprising one or more metallic ingredients in powder form. In either case, the powder form is preferably very fine, e. g. its particles being in the range of from 1 to 5 microns in diameter, preferably 3 to 5 microns in diameter.
DESCRIPTION OF THE DRAWINGS Reference will now be made by way of example to the accompanying drawings, in which: Figure 1 is a plan view of an anti-radiation device embodying the invention ; Figure 2 is a front view of the device, i. e. viewed from the top as seen in Figure 1 ; Figure 3 is a back view of the device ; Figure 4 is a side view of the device ; Figure 5 is a partial view corresponding to Figure 3 of a telescopic version of the device; Figure 6 is a front view of a mobile telephone with the Figure 1 device fitted to the stub aerial of the telephone ; for clarity, to show how the device clips to the stub aerial, the device is shown rotated out of its natural use position by 90 degrees ; for use, it is to be in a position rotated 90 degrees round the aerial towards the viewer, i. e. in the anti-clockwise direction has seen in Figure 1 ; and Figure 7 is a fragmentary cross-section of the sheet and coating of which the device is made.
Referring to the drawings, an anti-radiation device 10 is adapted for mounting to a mobile or like telephone 12. It is adapted for mounting to a substantially cylindrical aerial 14 of the telephone 12. Testing of the radiation from the aerial past the shield (i. e. to the front) is done using a radiation detector probe 16 with its tip 1 cm past the shield 18 of device 10.
The device 10 is substantially wholly in the form of sheet 20, with a thickness in the range of from 0. 1 to 0. 5 mm. The sheet 20 is provided with a coating 22 of paint.
The coating 22 is applied like a laquer, in 7 layers, each baked hard The sheet 20 has a major part 18 shaped to cover at least a quarter of the circumference of the cylindrical aerial 14 of the telephone 12, and has edge portions 24, 24 extending axially of the aerial which are interrupted to reduce the shielding effect of the sheet 20 at those portions 24, 24, the interruptions being in the form of holes or slits 26.
The device comprises a clip 28 to fit it to the cylindrical aerial 14 of the telephone 12, folded down internally of the major part 18, and is interrupted by slots 30 to reduce its shielding effect on the static transmitter/receiver side (the bottom as seen in Figure 1) of the aerial 14, i. e. on the opposite side of the major part 18 to the head (which, in use, will be in the position of probe 16, Figure 1). A metal stud 32 of brass is fitted to the upper end 34 of the device 10. Said major part 18 of said sheet 20 is curved and/or bent, as seen clearly Figure 1, and it comprises and information plate 36 fitted inside the sheet 20. This plate 36 years provided with teeth 38 that fit into the abovementioned holes 26 to hold the plate 36 to the remainder of the device 10, and is welded to the latter.
The device 10 has a size adapted to fit to a standard diameter cylindrical aerial of a mobile telephone, e. g. a 6, 8 or 10 mm diameter aerial. For a stub aerial of diameter 8 mm, the major shielding part 18 has a width, horizontally as seen in Figure 1, of 10 mm and the clip 28 a width of 9 mm in the same direction. A folded bridge 40 interconnecting clip 28 and major part 18 (which are about 1 mm apart) has a width of 4 mm in the same direction. Brass stud 32 has a diameter of 4 mm. The device 10 has an overall depth of 10 mm, in the vertical direction as seen in Figure 1. Clip 28 has a height of 6 mm, in the vertical direction as seen in Figure 4, and its slit 30 a width of 1 mm. For a stub aerial 14 of diameter 6 mm, the device 10 may be only 21 mm high, and of thinner sheet 20, and other dimensions may vary accordingly. For a stub aerial 14 of diameter 10 mm, the device 10 may be 30 mm high, and of thick sheet 20, and other dimensions may vary accordingly.
As seen in Figure 5, the device 10 is adapted to cover a telescopic aerial of a telephone 12, the device 10 being telescopic, by the following means. The series of the major parts 181, 182 (like part 18) are connecte to slide one upon another, in the vertical direction as seen in Figure 5, by means of folded lugs 42 of part 182 sliding along edges 44 of part 181 down to the restraint of lugs 46 of part 181. One or more of parts 181, 182 may be provided with a clip 28, and the top one of parts such as 181, 182 is provided with a stud 32. As in the case of Figure 6, the lowest clip 28 is arrange at the root end 48 of aerial 14, and the stud 32 is at the remote/free end 50 of aerial 14.
It will be apparent to one skilled in the art, that features of the different embodiments disclosed herein may be omitted, selected, combine or exchanged and the invention is considered to extend to any new and inventive combination thus formed.

Claims (30)

  1. CLAIMS 1. An anti-radiation device which is adapted for mounting to a mobile or like telephone.
  2. 2. A device is claimed in claim 1, characterised in that it is adapted for mounting to a substantially cylindrical aerial of the telephone.
  3. 3. A device has claimed in claimed 1 or 2, characterised in that it is principally or substantially wholly made of electrically conductive metal.
  4. 4. A device as claimed in claim 3, characterised in that the metal comprises at least 50% copper w/w.
  5. 5. A device as claimed in claim 3, characterised in that the metal comprises at least 70% copper w/w.
  6. 6. A device as claimed in any one of claims 3 to 5, characterised in that the metal comprises at least 10% magnetic material w/w.
  7. 7. A device as claimed in any one of claims 3 to 6, characterised in that the metal comprises at least 10% other than copper and magnetic material w/w.
  8. 8. A device as claimed in any one of claims 1 to 7, characterised in that it is substantially wholly in the form of sheet.
  9. 9. A device as claimed in claim 8, characterised in that the sheet has a thickness in the range of from 0. 1 to 0. 5 mm
  10. 10. A device as claimed in claim 8 or 9, characterised in that the sheet is coated with paint.
  11. 11. A device as claimed in claim 10, characterised in that the paint comprises a metallic powder.
  12. 12. A device as claimed in claim 11, characterised in that the powder comprises copper and/or aluminium.
  13. 13. A device as claimed in claim 10 or 11, characterised in that the powder comprises magnetic material.
  14. 14. A device as claimed in any one of claims 10 to 13, characterised in that the powder comprises metallic material other than copper, aluminium and magnetic material.
  15. 15. A device as claimed in any one of claims 10 to 14, characterised in that the coating of paint has a thickness in the range of from 0. 1 to 0. 5 times the thickness of the sheet.
  16. 16. A device as claimed in claim 15, characterised in that the coating has a thickness of substantially a quarter that of the sheet.
  17. 17. A device as claimed in any one of claims 1 to 16, characterised in that the sheet has a major part shaped to cover in the range of from a quarter to a half of the circumference of a cylindrical aerial of the telephone.
  18. 18. A device as claimed in claim 17, characterised in that said major part is shaped to cover substantially 0. 4 of the circumference of the aerial.
  19. 19. A device as claimed in any one of claims 1 to 18, characterised in that said sheet has edge portions extending axially of the aerial which are interrupted to reduce the shielding effect of the sheet at those portions.
  20. 20. A device as claimed in claim 19, characterised in that the interruptions are in the form of holes and/or slits.
  21. 21. A device as claimed in any one of claims 1 to 20, characterised in that it comprises a clip to fit it to a substantially cylindrical aerial of the telephone.
  22. 22. A device as claimed in claim 21, characterised in that the clip is folded down from a major part of the sheet.
  23. 23. A device as claimed in claim 21 or 22, characterised in that the clip is interrupted to reduce its shielding effect.
  24. 24. A device as claimed in any one of claims 1 to 23, characterised in that it comprises a metal stud fitted to one end thereof.
  25. 25. A device as claimed in claim 24, characterised in that the stud is of brass.
  26. 26. A device as claimed in any one of claims 1 to 25, characterised in that it is substantially wholly in the form of a sheet and said sheet is curved and/or bent and it comprises at least one information plate fitted inside and/or outside the sheet.
  27. 27. A device as claimed in any one of claims 1 to 26, characterised in that it has a size adapted to fit a standard diameter cylindrical aerial of a mobile telephone.
  28. 28. A device as claimed in any one of claims 1 to 27, characterised in that it has a size adapted to fit to a telephone cylindrical aerial of diameter 6, 8 or 10 mm.
  29. 29. A device as claimed in any one of claims 1 to 28, characterised in that it is adapted to cover a telescopic aerial of a telephone.
  30. 30. An anti-radiation device as claimed in claim 29, having a major radiation-shielding portion arrange to be interpose between the aerial and the user's ear.
    30. A device as claimed in claimed 29, characterised in that it is telescopic.
    31. An anti-radiation device substantially according to any example hereinbefore described.
    32. An anti-radiation device substantially according to any example hereinbefore described with reference to and illustrated in the accompanying drawings.
    33. An anti-radiation device as claimed in any one of claims 1 to 32, mounted to a mobile or like telephone. 34. An anti-radiation device as claimed in claim 33, having a major radiation-shielding portion arrange to be interpose between the aerial and the user's ear.
    Amendments to the claims have been filed as follows
    1. An anti-radiation device which is adapted for mounting to a substantially cylindrical aerial of a mobile telephone or the like (as hereinbefore deEmed), whieh device is formed from a sheet, which sheet is folded to form a major part for covering some but not all of the circumference of the aerial and an aerial-fitting clip part.
    2. A device as claimed in claim 1, characterised in that it is substantially wholly made of electrically conductive material.
    3. A device as claimed in claim 2, characterised in that the said material comprises at least 50% copper w/w.
    4. A device as claimed in claim 2, characterised in that the said material comprises at least 70% copper w/w.
    5. A device as claimed in any one of claims 2 to 4, characterised in that the said material comprises at least 10% magnetic material w/w.
    6. A device as claimed in any one of claims 2 to 5, characterised in that the said material comprises at least 10% other than copper and magnetic material w/w.
    7. A device as claimed in any one of claims 1 to 6, characterised in that the sheet has a thickness in the range of from 0. 1 to 0. 5 mm.
    8. A device as claimed in any one of claims 1 to 7, characterised in that the sheet is coated with paint.
    9. A device as claimed in claim 8, characterised in that the paint comprises a metallic powder.
    10. A device as claimed in claim 9, characterised in that the powder comprises copper and/or aluminium.
    11. A device as claimed in claim 9 or 10, characterised in that the powder comprises magnetic material.
    12. A device as claimed in any one of claims 9 to 11, characterised in that the powder comprises metallic material other than copper, aluminium and magnetic material.
    13. A device as claimed in any one of claims 9 to 12, characterised in that the coating of paint has a thickness in the range of from 0. 1 to 0. 5 times the thickness of the sheet.
    14. A device as claimed in claim 13, characterised in that the coating has a thickness of substantially a quarter that of the sheet.
    15. A device as claimed in any one of claims 1 to 14, characterised in that the major part is shaped to cover in the range Or from a quarter to a half of the circumference of a cylindrical aerial of the telephone.
    16. A device as claimed in claim 15, characterised in that the major part is shaped to cover substantially 0. 4 of the circumference of the aerial.
    17. A device as claimed in any one of claims 1 to 16, characterised in that said sheet has portions at edges extending axially of the aerial which portions are interrupted to reduce the shielding effect of the sheet at these portions.
    18. A device as claimed in claim 17, characterised in that the interruptions are in the form of holes and/or slits.
    19. A device as claimed in any one of claims 1 to 18, characterised in that the clip part is interrupted to reduce its shielding effect.
    20. A device as claimed in any one of claims 1 to 19, characterised in that the device has top and bottom ends and comprises a metal stud fitted to one such end.
    21. A device as claimed in claim 20, characterised in that the stud is of brass.
    22. A device as claimed in any one of claims 1 to 21, characterised in that the sheet is curved and/or bent and the device comprises at least one information plate fitted inside and/or outside such curve or bend of the sheet.
    23. A device as claimed in any one of claims 1 to 22, characterised in that it has a size adapted to fit a standard diameter cylindrical aerial of a mobile telephone.
    24. A device as claimed in any one of claims 1 to 23, characterised in that it has a size adapted to fit to a cylindrical aerial of diameter 6, 8 or 10 mm.
    25. A device as claimed in any one of claims 1 to 24, characterised in that it is adapted to cover a telescopic aerial of a mobile telephone.
    26. A device as claimed in claimed 25, characterised in that it is telescopic.
    27. An anti-radiation device substantially according to any example hereinbefore described.
    28. An anti-radiation device substantially according to any example hereinbefore described with reference to and illustrated in the accompanying drawings.
    29. An anti-radiation device as claimed in any one of claims 1 to 28, mounted to a mobile telephone or the like.
GB9910477A 1999-05-06 1999-05-06 Anti-radiation device Expired - Fee Related GB2349747B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB9910477A GB2349747B (en) 1999-05-06 1999-05-06 Anti-radiation device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB9910477A GB2349747B (en) 1999-05-06 1999-05-06 Anti-radiation device

Publications (3)

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GB9910477D0 GB9910477D0 (en) 1999-07-07
GB2349747A true GB2349747A (en) 2000-11-08
GB2349747B GB2349747B (en) 2001-03-21

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2363909A (en) * 2000-04-26 2002-01-09 Ecoflow Ltd Device for reducing the harmful effects of electromagnetic radiation from a mobile phone.
ES2170663A1 (en) * 2000-05-19 2002-08-01 Hueto Leon Francisco M Polarised radiation protection screen for mobile telephones

Citations (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5338896A (en) * 1993-09-03 1994-08-16 Danforth David M Shield device for cellular phones
GB2276494A (en) * 1993-03-24 1994-09-28 Mcgrath James Joseph Mobile telephone shield.
WO1994022233A1 (en) * 1993-03-12 1994-09-29 Bickert Paul F Radio frequency radiation shield for hand-held radio phone
DE29610165U1 (en) * 1996-06-10 1996-08-22 Schmitz, Wolfgang, Dr.med., 68165 Mannheim Partial shielding for antennas of cordless high-frequency transmitters
US5613221A (en) * 1993-04-12 1997-03-18 J. R. Hunt Ventures Radiation shield for cellular telephones
DE29621107U1 (en) * 1996-12-05 1997-05-22 Schmitz, Wolfgang, Dr.med., 68165 Mannheim Removable device for partial shielding of magnetic field components for antennas of handheld radios
JPH09223888A (en) * 1996-02-15 1997-08-26 Saburo Ishikawa Electromagnetic shield plate of portable telephone
EP0805562A2 (en) * 1996-04-29 1997-11-05 Siemens Business Communication Systems, Inc. Radio-frequency hearing aid protector for wireless communications products
US5694137A (en) * 1995-04-05 1997-12-02 Wood; Richard L. Communication device antenna shield
US5826201A (en) * 1992-11-25 1998-10-20 Asterion, Inc. Antenna microwave shield for cellular telephone
WO1999001907A1 (en) * 1997-07-02 1999-01-14 Helmut Podobnik Protection from electrosmog
DE29723741U1 (en) * 1997-06-05 1999-02-18 Ahrens, Elvira, 38855 Wernigerode Radiation protection device for handheld radios, in particular cordless telephones

Patent Citations (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5826201A (en) * 1992-11-25 1998-10-20 Asterion, Inc. Antenna microwave shield for cellular telephone
WO1994022233A1 (en) * 1993-03-12 1994-09-29 Bickert Paul F Radio frequency radiation shield for hand-held radio phone
GB2276494A (en) * 1993-03-24 1994-09-28 Mcgrath James Joseph Mobile telephone shield.
US5613221A (en) * 1993-04-12 1997-03-18 J. R. Hunt Ventures Radiation shield for cellular telephones
US5338896A (en) * 1993-09-03 1994-08-16 Danforth David M Shield device for cellular phones
US5694137A (en) * 1995-04-05 1997-12-02 Wood; Richard L. Communication device antenna shield
JPH09223888A (en) * 1996-02-15 1997-08-26 Saburo Ishikawa Electromagnetic shield plate of portable telephone
EP0805562A2 (en) * 1996-04-29 1997-11-05 Siemens Business Communication Systems, Inc. Radio-frequency hearing aid protector for wireless communications products
DE29610165U1 (en) * 1996-06-10 1996-08-22 Schmitz, Wolfgang, Dr.med., 68165 Mannheim Partial shielding for antennas of cordless high-frequency transmitters
DE29621107U1 (en) * 1996-12-05 1997-05-22 Schmitz, Wolfgang, Dr.med., 68165 Mannheim Removable device for partial shielding of magnetic field components for antennas of handheld radios
DE29723741U1 (en) * 1997-06-05 1999-02-18 Ahrens, Elvira, 38855 Wernigerode Radiation protection device for handheld radios, in particular cordless telephones
WO1999001907A1 (en) * 1997-07-02 1999-01-14 Helmut Podobnik Protection from electrosmog

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2363909A (en) * 2000-04-26 2002-01-09 Ecoflow Ltd Device for reducing the harmful effects of electromagnetic radiation from a mobile phone.
ES2170663A1 (en) * 2000-05-19 2002-08-01 Hueto Leon Francisco M Polarised radiation protection screen for mobile telephones

Also Published As

Publication number Publication date
GB9910477D0 (en) 1999-07-07
GB2349747B (en) 2001-03-21

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Date Code Title Description
PCNP Patent ceased through non-payment of renewal fee

Effective date: 20030506