WO2001035487A1

WO2001035487A1 - An anti-radiations reflecting metallic shield system (arrmss)

Info

Publication number: WO2001035487A1
Application number: PCT/IT2000/000445
Authority: WO
Inventors: Sergio Paolo Diodato; Giovanni Savastano
Original assignee: Sergio Paolo Diodato; Giovanni Savastano
Priority date: 1999-11-08
Filing date: 2000-11-07
Publication date: 2001-05-17
Also published as: ITCH990010A1; IT1315447B1; ITCH990010A0; AU1883901A; WO2001035487A8

Abstract

What is being brought in, is an Anti-Radiations Reflecting Metallic Shield System (ARRMSS). It can be applied on every kind of radio receiving-transmitting set operating by means of electromagnetic waves, like mobile phones, cordless phones, walkie-talkies and so on. The ARRMSS shall be disposed on the outside of the transceiver, between the antenna and the user, in a removable or fixed way, preferably at an optimal distance scientifically calculated. The ARRMSS consists in a conductor-reflector element (1), made of a rigid or flexible metallic shield, that can be constituted with a plane, or with a shell or cut out or shaped like a strip. It shall be applied in such a way so as to cover the entire height of the transceiver, simply interposed, or wrapping or covering the antenna (2) for nearly the half of its circumference so as to concentrate and reflect the radiations in a single direction opposite to the user. In fact, according to the well-known principle of the 'electric images', the omnidirectional radiation diagram of the antenna will be turned into a monodirectional or directional one (radiation angle is about 180°).

Description

DESCRIPTION

An Anti-Radiations Reflecting Metallic Shield System (ARRMSS)

Technical Field

What is being brought in, is an Anti-Radiations Reflecting Metallic Shield System (ARRMSS). It can be applied on every kind of radio receiving-transmitting set operating by means of electromagnetic waves, like mobile phones, cordless phones, walkie-talkies and so on. The ARRMSS shall be disposed on the outside of the transceiver, between the antenna and the user, in a removable or fixed way, preferably at an optimal distance scientifically calculated. The ARRMSS consists in a conductor-reflector element (1), made of a rigid or flexible metallic shield, that can be constituted with a plane, or with a shell or cut out or shaped like a strip. It shall be applied in such a way so as to cover the entire height of the transceiver, simply interposed, wrapping or covering the antenna (2) for nearly the half of its circumference so as to concentrate and reflect the radiations in a single direction opposite to the user. In fact, according to the well- known principle of the "electric images", the omnidirectional radiation diagram of the antenna will be turned into a monodirectional or directional one (radiation angle is about 180°).

Background Art The state of the art concerning this matter is summarised in the article edited by Gruppo Editoriale Futura, written by Elena Rosa, published at the pages 66-67 of the italian magazine "Telefoni Cellulari Magazine" n. 19, autumn 1999. Here are the most significant parts of the article: «The leather case CLOSER is a protective covering for mobiles, which "destroys electromagnetic waves" and dangerous microwaves emitted by cellular phones. CLOSER is distributed by Stefano Uno. DEFENDER ENERGY, distributed by Eltron, is a plaquette in baked clay, produced with selected materials which are melted at 1600° C. This process allows to obtain the molecular structure able to defend the user from the electromagnetic waves emitted by the mobile phone. EATWAVE, distributed by MMT, is a radiations absorber, useful for every source of electromagnetic waves: mobile phones, Personal Computers, electric razors, microwave ovens. Thanks to its particular molecular structure, when Eatwave is impressed by electromagnetic fields, it absorbs the induced energy modifying the orbit of its own electrons. Eatwave functions as a reservoir which has to be emptied when it is full (it needs a 20 minutes discharge for one hour of running).

[^{■ ■} •]•

FONERSAFE, distributed by TEC-Planet, eliminates up to 90% of the antenna's radiations, and of the EMF emissions. Fonersafe is a little "spongy" cap that has to be placed on the antenna of the mobile [...]. GARDION, distributed by Onceas, is an adesive plaquette in tormalina, a natural material which can be found in Brazil and in some parts of Asia. The tormalina releases negative ions. These neutralize the positive ones - produced by the electromagnetic waves - that are absorbed by our body.

NORAD consists in two balls - Norad 1 and Norad 2 - containing Lantanidi salts (rare earths). The two balls enter into action instantaneously when stimulated by electromagnetic radiations. Thanks to the solution of Lantanidi salts, Norad 1 and Norad 2 create a shield of electromagnetic resonance, eliminating in this way the noxious effects of the radiations.[...].

SAFETY BUTTERFLY, distributed by Ricla, is a funny butterfly-shaped device made with silicon and glazed carbon. Put on the mobile, it absorbs part of the electromagnetic field. SIKURA, distributed by DAI, is a particular case which deadens the electromagnetic waves and reduces the thermic effect. Also SORICAP - a little protective cushion which has to be placed on the receiver of the mobile - reduces the thermic effect produced by electromagnetic waves.

WAVE GUARD deadens separately the magnetic and the electric waves of the electromagnetic field generated by the mobile phone. An aluminium thin sheet reduces the electric wave, whereas a coil produces a magnetic wave which counterbalances the one produced by the mobile.[...]. ZEROPA is a ladybird-shaped button which has to be placed on the mobile to protect the user from the electromagnetic field. It is composed by five different kinds of baked clay forming a crystalline molecular structure which remains stable up to a temperature higher than 1600° C. Zeropa succeeds in absorbing the 70% of the law frequency waves, in turning them into shorter infra-red rays, and then in irradiating them outside ».

Besides the devices described in the article edited by Elena Rosa, there is also the cellular phone TELITAL GM 410, provided with a directional antenna that in any case does not use our principle. To reduce the risks of the exposure to the electromagnetic waves, on the market are offered also extensions for microphone and receivers. These do allow to remove the transmitting source from the head of the user, but do not shield the radiations that can be noxious for other parts of the human body. Regarding to the international patents research. Searching on Internet at the address: http:// itespacenet.com, we have seen that in the abstracts of the international patents of the International Bureau of the World Intellectual Property Organization, there are 94 patents containing the words: "radiation" or "radiations", and "metal" or "metallic"; and "shield" and "shielding". We have find that only the patent n. WO 94/26000 is similar to our one, but it is not the same. In fact we can read on the abstract: « An anti -electromagnetic field antenna for cellular telephones. The antenna comprises a folder monopole driver antenna adapted to be attached to a coaxial cable and means for shielding the user's head from radio frequency electromagnetic fields, The shielding means consists of a ground-plane circuit including at least two radials electrically connected to the shielding of the transceiver coaxial cable and means for providing inductance and capacitance to the ground plane circuit. The ground- plane circuit is contained on an elecrical circuit board and the radials are of a metallic foil composition and are printed on the circuit board. This specially designed ground-plane acts as a shield by absorbing and reflecting radio-frequency electromagnetic fields away from the user's head and eliminating stray currents and radiation from the transceiver and coaxial cable. »

Disclosure of invention

Considering that the daily and protracted usage of mobile phones subject us to a long exposure to the electromagnetic waves, the protecting devices described till this moment seem inadequate. On the market are already offered cellular phones with a metallic or metallized shell, but this one does not cover the most dangerous part of the mobile phone: the antenna. In fact the electromagnetic waves - which are irradiated by the antenna according to the typical lobe radiation diagrams (see Fig. 1 A) - are harmful for the health, especially when: they are irradiated at high frequencies, the source of the radiations comes into direct contact with the head of the user, and the exposure is particularly prolonged.

From all these considerations arises the need to protect the user with the following shielding system. We start by considering that it is easy to eliminate the irradiation in a certain direction of an antenna (in our case, in the user side), by placing, parallely to the antenna, a reflecting metallic shield. This shield is placed on the side where the radiation must be eliminated. Besides the classical reflectors, the metallic shield may be for instance an aluminium stripe placed at an optimal distance from the antenna, a little longer than the antenna itself.

In this way the waves reflected by the shield are exclusively transmitted on the side of the antenna opposite to the stripe according with the telecommunication theory (see Fig. 1 B). As a matter of fact this stripe works as a conductor-reflecting element, creating the effect of a disposition of an "antenna image" fed by the mean of induction, with a current in opposition to the "real antenna". In order to obtain that the "image antenna" radiation is summed up in phase to that of the "real antenna", the distance between them must be half-lambda (lambda is the wavelength obtained by the formula: elf). For this reason the reflecting shield has to be placed at a distance of a quarter-lambda from the antenna plane, according with the telecommunication theory (see for example the book: Radiotecnica e televisione by A. Montanari and A. Cupido, Edizioni Cupido, Citta di Castello 1982, page 623). The ARRMSS consists of a metal conductor-reflecting element - which can be, besides the classical reflectors, a little stick, a wire, a thin sheet, a shell, a wire-net etc.- with fixed proper dimensions, placed or enclosed, at right distance (if possible the shield must be placed at an optimal distance, to obtain the best shielding power) from antenna, between the user and the transceiver.

At the present time the ARRMSS can be placed - directly on the transceiver or on its protective case (see Fig. 7) - operating in systems like E-TACS, GSM 900, DCS 1800, PCS 1900 MHz (for the U.S.A.) and in UMTS in the near future, (see Figures 3, 4, 5, 6, 9) and on walkie- talkies, cordless phones (see Fig. 8) and other devices working at different frequencies. It is possible also to foresee the installation of the ARRMSS on or inside the devices that will be produced in the future (see Fig. 10, 11), even if working at frequencies not in use today.

The originality of the invention (the inventive quid) consists in having applied on rice-transmitting sets, mobile phones, cordless phones etc., what has been already theorised in the technology for the construction of directive antennas. According to these theories, based on the exposed principles, the main system to concentrate the radiation consists in disposing a conductor-reflecting surface behind the antenna, so as to turn the omnidirectional radiation diagram into a monodirectional or directional one (radiation angle is about 180°) (see Fig. 1). To make this are used the classical reflectors who can deflect the best part of the radiations. Moreover we have produced and tested three prototypes, using the same principle. In the first case (see Figures 5, 6), the prototype of shield consists in a flexible aluminium thin sheet (1) which is 0,05 mm. thick. The thin sheet has been cut out as a stripe and has been sticked with a bi-adhesive tape on a cellular phone in such a way so as to cover the entire height of the transceiver, wrapping and covering the antenna (2) for nearly the half of its circumference.

This prototype, put into direct contact with the antenna (2), blocked over the 60% of the radiations directed towards the user, demonstrating in this way the validity and the efficacy of this system. In the second case, the prototype of shield constituted by a rigid common wire of zinc-plated iron has been assembled - parallel and removed - on the antenna of a simple walkie-talkie. In this way it has been noticed an attenuation up to more than 90% and more of the radiations emitted towards the user. The third prototype (see Fig. 8) refers to the assemblage of the shield on a cordless phone. The shield (1) is constituted by a zinc-plated iron stick which is 2 cm. wide and 2 mm. thick. The height of this stick exceeds the height of the antenna (2). In this way it has been noticed a reduction of about the 80% of the radiations.

Concerning to the efficiency of the tested devices, it is important to make clear that there are no variations of the radio-range and the performance after the shield installation.

To obtain the best efficiency of the electromagnetic shield, we have calculated the wave length (or lambda) of the transmitted frequency, according to the formula: c/f - where "c" is the light speed and "f is the frequency. So we have calculated that, at the frequency of 1800 MHz, the wavelength is 0, 166 meters.

By considering this data, and since the distance must be a little more than 0,1 lambda (see the table at page 18: Radioelettronica e televisione by Grasso, Liberatore, Ricci), we have determined that the optimal distance between the antenna and the reflector is 0,025 meters. Then the optimal distance to dispose the shield (1) from an antenna (2) working at 1900MHz is about 1 ,57 cm., at 1800MHz is 2,5 cm., and at 900 MHz is 5 cm. (see Figures 9, 10, 11)

In any case, according to the verifications carried out, the shield results efficacious also if it comes into direct contact with the antenna, say at shorter distance than the ones we have theorised, (see Figures 3, 4, 5, 6, 7)

The utilization of our electromagnetic shield could also allow to the pace-makers bearers the use of the mobile phones, shielding the electromagnetic interferences. The ARRMSS may be used to shield any electromagnetic interference source as soon as on household appliances, like electric razors, hairdryers, microwaves ovens etc. The shield can be utilised for fixed antennas and structures of the net too, broadcasting-stations and to protect the adjacent built-up areas from the radiations. Brief description of drawings

At page 1/7 there is a reproduction of the radiation diagrams from the book: Radioelettronica e televisione by A. Montanari and A. Cupido,

Edizioni Cupido, Citta di Castello 1982, page 623. Fig. 1 A: antenna's omnidirectional diagram of radiation. Fig. 1 B: antenna's monodirectional diagram of radiation, which is obtained placing a reflecting-conductor plane (1) (a metallic shielding element) parallelly to the antenna (2)

At page 2/7 the Fig. 2 represents a reflecting metallic shield (1) made with a rigid aluminium stripe which is 1mm. thick. The Fig. 3 represents the same stripe (1) stuck on the front surface of a mobile phone model Ericsson with a biadhesive tape. The distance of the shield from antenna (2) is about 1 cm.

The Fig. 4 represents the same stripe shield (1) in a lateral projection.

At page 3/7 the Fig. 5 represents a metallic shield (1) made with a flexible aluminium stripe, which is 0,05 mm. thick, stuck with biadhesive tape directly on the antenna (2) of a mobile phone model

Motorola. The Fig. 6 represents the same phone in a lateral projection.

At page 4/7 the Fig. 7 represents a rigid aluminium shield (1) disposed on a mobile phone case. In this way it is possible to realize easily the shielding on many models of mobile phones. It is possible to obtain the best distance (2,5 cm.) from an antenna (2) working at

1800 MHz too.

At page 5/7 the Fig. 8 represents a telescopic metallic shield (1) disposed on a cord less phone model Citizen. Obviously, when the antenna (2) is working and extended, also the shield (1) must be extended a little more over the antenna.

At page 6/7 Fig. 9 shows the shield (1) made with an aluminium sheet cut of and placed on the external side of the mobile phone model

Motorola.

For the moment in this way it is possible to obtain a good distance between the antenna (2) and the shield (1) either if they are not in parallel, but in the future it could be possible to produce devices disposing in parallel and automatically their right distances (at present: 1 ,57 cm., 2,5 cm., and 5 cm.) between the shield and the antenna in accordance with the frequency working.

At page 7/7 Fig. 10 and Fig. 11 show in a lateral view a mobile phone dual band that could be produced in the future.

This model, in Fig. 10, is working at 1800MHz. In fact the mobile antenna (2) is automatically placed at 5 cm. from the shield (1) by means of a flooting device. The shield could be constituted, for example, by an aluminium sheet disposed in parallel with the antenna into the transceiver.

In Fig. 11 the same phone is working at 900Mhz, and the distance of the antenna (2) from the shield (1) is 2,5 cm.

Best mode for carrying out the invention

Considering the best mode for carrying out the invention we must divide in two categories the target of application of the ARRMMSS: 1) Application on devices already produced or in production;

2) Application on devices that will be designed and produced in future. In the first case, for the devices like the mobile phones that have the shape of parallelepiped, the fastest and easy mode to set the invention is cutting off the shape of the shield by rigid aluminium sheets (1 mm. thick), modelled and folded in stripes by pressing (see Fig. 2). The stripes can be varnished on the external side, and on the internal side it must be disposed a biadhesive tape to stick the shield to the device. As we have described the optimal setting of the shield (to obtain the best shielding power) is at 5 cm. from antennas working at 900 MHz; 2,5 cm. from antennas working at 1800 MHz; and about 1 ,57 cm. from antennas working at 1900 MHz. For this reasons it would be preferable to predispose the shape of the shield (1) to be set at those distances from antennas (2). Practically the operation can be made easily and advantageously for distances till 2,5 cm., considering that in some models of transceivers the antenna is placed behind and far from the earphone, but, as we have seen, the shield works even to shorter distances though with a lower efficiency (see figures 3, 4, 5, 6, 7). On the mobile phones opening by means of hinges, (see Fig. 9) the distance of the shield from antenna is quite enough. It will be sufficientt to cut off the shield, shaped on shell, and stick it on the external side of the mobile phone (the side with the earphone). When the device is working the shield (1) automatically comes to be at 5 cm. from the antenna (2), even if not in parallel position. Obviously the operation can be finished by varnishing the external side of the shield. For the devices that will be produced in the future (see Figures 10, 11), the best mode to carry out the invention is to make a dual band mobile telephone endowed of a mobile antenna (2) that automatically is placed parallelly and at right distance from the shield (1): at 5 or 2,5 cm. according with the working frequency.

Claims

1) We claim an anti-electromagnetic radiations reflecting metallic shield (1), which has to be disposed on radio transceiver, mobile phones, cordless phones, etc, characterized as a conductor-reflecting element which is interposed between the radiant antenna (2) and the user, in such a way to change the omnidirectional radiations into monodirectional or directional ones and to direct them in the direction opposite to the user. We claim, in the same time, the definition of the optimal distance in order to obtain the best electromagnetic shielding reflector, to be set in a fixed or removable way, between the radiant antenna (2) and the conductor-reflecting element (1) to protect the user.

2) We claim an anti-electromagnetic radiations reflecting metallic shield (1), to be disposed on the rice-transmitting sets - as described in claim 1 - when the reflecting conductor element is composed by one plate or more, and/or thin sheets, and/or shell, and/or wire, and/or plaits, and/or by flexible or rigid wire-nets aggregated in different ways, as well as by pasted metallic powder. 3) We claim the right distance between the radiant element (2) and the shield (1) as described in claim n. 1 , scientifically calculated for every average distance in the emission range of the transceiver and also obtained with general flooting systems and flooting systems fixed by means of hinges (or joints or mechanical joints), returning bars systems, telescopic systems, pantographic systems - fixed or removable - which are directly set up on the transmitter and/or on their cases. 4) We claim the ARRMSS when it is assembled with others anti- radiations shielding systems, even if it is set up on electrical household appliances. ) We claim the ARRMSS when it is set up on transceiver antenna's of fixed structures as, for example, base transceiver stations (BTS), broadcasting- stations, to protect the adjacent built up areas.