US3778836A - Magnetic antenna having a block or circuit components therein - Google Patents

Magnetic antenna having a block or circuit components therein Download PDF

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US3778836A
US3778836A US3778836DA US3778836A US 3778836 A US3778836 A US 3778836A US 3778836D A US3778836D A US 3778836DA US 3778836 A US3778836 A US 3778836A
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Prior art keywords
magnetic
core
layer
receiver
antenna
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T Tanaka
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T Tanaka
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    • HELECTRICITY
    • H01BASIC ELECTRIC ELEMENTS
    • H01QANTENNAS, i.e. RADIO AERIALS
    • H01Q1/00Details of, or arrangements associated with, antennas
    • H01Q1/12Supports; Mounting means
    • H01Q1/22Supports; Mounting means by structural association with other equipment or articles
    • H01Q1/24Supports; Mounting means by structural association with other equipment or articles with receiving set
    • HELECTRICITY
    • H01BASIC ELECTRIC ELEMENTS
    • H01QANTENNAS, i.e. RADIO AERIALS
    • H01Q7/00Loop antennas with a substantially uniform current distribution around the loop and having a directional radiation pattern in a plane perpendicular to the plane of the loop
    • H01Q7/06Loop antennas with a substantially uniform current distribution around the loop and having a directional radiation pattern in a plane perpendicular to the plane of the loop with core of ferromagnetic material
    • H01Q7/08Ferrite rod or like elongated core

Abstract

An antenna for a receiver comprising a magnetic core in the form of a thin layer having a thickness less than 50 microns superposed on a casing of a receiver or on a block of components of the receiver, and a winding wound on said magnetic core and connected electrically to the components in the casing or in the block, the winding serving as the antenna for the receiver. A receiver which comprises said antenna.

Description

Related US. Application Data Continuation-in-part of Ser. No. 679,351, Oct. 31, 1967, abandoned.

Umted States Patent 1 111 3,778,836 Tanaka Dec. 11, 1973 [54] MAGNETIC ANTENNA'HAVING A BLOCK 3,271,718 9/1966 Shaw 336/234 x 3,372,395 3/1968 Kline 0R CIRCUIT COMPONENTS THEREIN 3,538,441 11/1970 Tanaka 343 702 X [76] Inventor: Takashi Tanaka, 340 Oaza Kisaichi,

Katano-cho, Kitakawachi-gun, FOREIGN PATENTS OR APPLICATIONS Osaka-f, Japan 1,090,140 6/1958 Germany 343/787 [2 Filed: p 27, 1971 OTHER PUBLICATIONS [21] App]. No.: 137,998 Polydoroff, W. .1 R.E.E.Ferromagnetic Loop Antennas, Radio-Electronic Eng. Edition of Radio & TV News, 11-1951, pp. 11-13, 24.

Polydoroff, W. J High-Frequency Magnetic Materials John Wiley & Sons, 1960, pp. 1-3.

Burgess, R. E., Iron-Cored Loop Receiving Aerial Wireless Engineer, 6-1946, pp. 172-178.

Primary Examiner-Rudolph V. Rolinec Assistant ExaminerWm. H. Punter Atz0rneyWenderoth, Lind & Ponack 5 7 ABSTRACT An antenna for a receiver comprising a magnetic core in the form of a thin layer having a thickness less than 50 microns superposed on a casing of a receiver or on a block of components of the receiver, and a winding wound on said magnetic core and connected electrically to the components in the casing or in the block, the winding serving as the antenna for the receiver. A receiver which comprises said antenna.

10 Claims, 7 Drawing Figures MAGNETIC ANTENNA HAVING A BLOCK OR CIRCUIT COMPONENTS THEREIN This is a continuation-in-part of application Ser. No. 679,351, filed Oct. 31, 1967, now abandoned.

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to an antenna for a receiver for electromagnetic waves such as a radio receiver, and more particularly to an antenna comprising a magnetic core in the form of a thin layer superposed on the casing of the receiver or on a block of components of the receiver.

2. Prior Art A conventional antenna for use in a receiver, such as a radio receiver, comprises a magnetic core having a winding thereon. The magnetic core consists of, for example, a ferrite material having a high magnetic permeability and is usually in the form of a rod, a plate, or a tube. It is well-known that the ratio of the length to the crosssectional area of a magnetic core is one of the factors which affects the sensitivity of an antenna having said magnetic core. A higher ratio results in a higher sensitivity. As a practical matter, it is not easy to obtain a higher ratio because the maximum length of the magnetic core is limited by the size of the casing containing the radio receiver. It is also difficult to reduce the cross-sectional area of the magnetic core of a ferrite because the ferrite has poor mechanical strength. For example, a thin rod or plate which is long is easily broken, if the receiver is dropped carelessly on the ground during handling. A tubular core has a higher mechanical strength than a rod core with the same cross-sectional area and length, but the tubular core has a larger outside dimension than a rod core.

It is desirable that a receiver be small in size. Recent developments in the electronic component industry have succeeded in miniaturizing the electronic components by employing various new elements, for example, transistors instead of electron tubes. Moreover, new techniques such as those for making micromodules and integrated circuits have increased the packing density of the components. On the other hand, it has not been possible to reduce the size of the antenna without decreasing the sensitivity and/or the mechanical strength thereof. Therefore, the conventional antenna occupies quite a large space in a radio receiver in comparison with the other miniaturized components and limits miniaturization of a receiver.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an antenna having a high sensitivity, a high mechanical strength and/or a small volume.

Another object of the invention is to provide an antenna comprising a magnetic core in the form of a thin layer having a thickness less than 50 microns superposed on the casing of a receiver or on a block of components of a receiver.

A further object of the invention is to provide a receiver, the casing of which has a magnetic core in the form of a thin layer superposed thereon which acts as an antenna.

A further object of the invention is to provide a receiver in which a block of components are combined with a magnetic core in the form of a thin layer superposed thereon.

The antenna according to the invention comprises a magnetic core in the form ofa thin layer superposed on a casing of a receiver or on a block of components of a receiver and a winding on said magnetic core.

BRIEF DESCRIPTION OF THE FIGURES The invention will now be described in connection with the accompanying drawings, in which:

FIG. 1 is a perspective view of one embodiment of an antenna according to the invention, partly broken away;

FIG. 2 is a longitudinal sectional view of the antenna of FIG. 1;

FIG. 3 is a cross-sectional view taken along the line 3-3 of FIG. 2;

FIG. 4 is a perspective view, partly broken away, of

another embodiment;

FIG. 5 is a longitudinal sectional view of the antenna of FIG. 4;

FIG. 6 is a cross-sectional view, similar to FIG. 3, showing an embodiment in which a laminated magentic core is used; and

FIG. 7 is a cross-sectional view similar to FIG. 3 showing an embodiment in which a magnetic core is rolled on the casing.

DESCRIPTION OF PREFERRED EMBODIMENTS The present invention is an antenna for use in a receiver for electromagnetic waves, which antenna comprises a magnetic core in the form ofa thin layer superposed on the cylindrical portion of a casing of the receiver or on a block of components of the receiver, said layer having a thickness less than 50 microns. The provision of a magnetic core in the form of a layer superposed on a casing or on a block of components makes the cross-sectional area of the magnetic material of the core smaller and increases the ratio of this length to the cross-sectional area. The magnetic core according to this invention is very thin, but the overall assembly has a higher mechanical strength than conventional antenna cores, because the casing or a block of components themselves strengthens said magnetic core. A magnetic core in the form of a thin layer superposed on the casing or the block of components requires no special space for the antenna and miniaturizes the receiver in accordance with this invention. Referring to FIGS. 1, 2 and 3, reference character 11 designates the right cylindrical portion of a casing of a receiver. The portion 11 has a hollow interior 12. All the components of the receiver, for example, resistors, transformers, transistors and speakers (not shown in the FIGS.) are combined together into a receiver network and are positioned in the hollow interior 12 of the casing portion 11.

A magnetic core 13 in the form of a thin layer having a thickness less than 50 microns is superposed on the casing portion 11. The magnetic core according to the invention can be prepared from any available magnetic material having a high magnetic permeability.

A winding 14 is wound on the magnetic core 13 by a per-se well known method for making an antenna for a receiver and the winding 14 is coupled to the receiver components positioned in the hollow interior 12. It is preferable that the core 13 and the winding 14 be covered by a plastic .film 15, such as vinyl or epoxy, in order to provide the antenna with a high resistance to moisture.

The casing has a front cover 16 and a back cover 17. These covers 16 and 17 protect the components in the hollow interior 12. The controlling components, such as tuning or switching components, are positioned nearest to the covers 16 and 17 for easy handling.

Referring to FIGS. 4 and 5, a block 21 of components is made of various components combined together into an electrical circuit and is cast or molded into a simple cylindrical form, such as a circular cylinder, a plate or a parallelepiped by using suitable plastics such as epoxy resin or polyester resin. The necessary lead wires 22 of the block 21 extend to the casting or molding material and are connected with other components so as to form a receiver network.

The block 21 has a magnetic core 23 in the form of a thin layer having a thickness less than 50 microns superposed thereon, a winding 24 wound on the core 23, and a protection film 25 which covers the core 23 and the winding 24, as described in connection with the embodiment of FIGS. 1-3.

Materials which can be used for said magnetic cores are iron, iron nickel alloys, various ferrites and powder cores. The magnetic core in the form of a thin layer can be superposed on the casing 11 or on the block 21 by using per-se well known techniques, such as adhesion of magnetic sheets or magnetic particles, electroless plating, vacuum deposition or applying a magnetic paste containing magnetic powder, such as iron powder, iron alloy powder, or ferrite powder and suitable and available binding material, such as epoxy, polyester and vinyl.

Metals have very low electrical resistivities. Therefore, when a magnetic sheet made of a metal such as iron or nickel alloys is superposed on the casing 11 (or on the block 21), care should be taken that the magnetic core 13 has at least one gap 18 to prevent an electrically short circuited winding of the core 13, as shown in FIG. 3. In addition, it is desirable for preventing eddy currents that a laminated magnetic core composed of very thin individual layers 13a, 13b, and 130, as shown in FIG. 6, and together having a thickness of 50 microns be employed instead of a magnetic core in one body, such as the layer 13 of FIG. 3 or 23 of FIG. 5. It is preferable to use a magnetic core in the form of a single thin layer 13d wrapped a plurality of times around the casing 11, as shown in FIG. 7. The same wrapping can be placed on block 21 shown in FIG. 5. The magnetic core l3d has the same effect when it is in the form of the laminated core in FIG. 7 for the prevention of the eddy current and needs no gap, such as the gap 18 shown in FIG. 3.

What is claimed is:

1. An antenna consisting essentially of a casing for a receiver having at least a portion thereof in the shape of a cylinder, a magnetic core in the form of a thin layer consisting of high magnetic permeability material superposed on the cylindrical portion of the casing, said layer having a thickness less than 50 microns and having substantially no intrinsic strength and a winding wound on said magnetic core, the casing supplying the strength for supporting the winding and the core.

2. An antenna as claimed in claim 1 wherein said magnetic core is of a magnetic metal and has at least one gap therein extending the length of said core parallel to the longitudinal axis thereof.

3. An antenna as claimed in claim 1 wherein said thin layer is a thin sheet of magnetic metal wrapped around said casing a plurality of times the total thickness of the layer being less than 50 microns.

4. The combination as claimed in claim 1 in which said thin layer is a single layer of magnetic material.

5. The combination as claimed in claim 1 in which said thin layer is a plurality of thicknesses of magnetic material having a total thickness of less than 50 mi crons.

6. In combination, a block of components for a receiver having at least a portion thereof in the shape of a cylinder and an antenna consisting essentially of a magnetic core in the form of a thin layer consisting of high magnetic permeability material superposed on the cylindrical portion of said block of components, said layer having a thickness less than 50 microns and having substantially no intrinsic strength, and a winding on said magnetic core.

7. The combination as claimed in claim 6 wherein said magnetic core is of a magnetic metal and has at least one gap therein extending the length of said core parallel to the longitudinal axis thereof.

8. The combination as claimed in claim 6 wherein said thin layer is a thin sheet of magnetic metal wrapped around said block of components a plurality of times, the total thickness of the layer being less than 50 microns.

9. The combination as claimed in claim 6 in which said thin layer is a single layer of magnetic material.

10. The combination as claimed in claim 6 in which said thin layer is a plurality of thicknesses of magnetic material having a total thickness of less than 50 microns.

Claims (10)

1. An antenna consisting essentially of a casing for a receiver having at least a portion thereof in the shape of a cylinder, a magnetic core in the form of a thin layer consisting of high magnetic permeability material superposed on the cylindrical portion of the casing, said layer having a thickness less than 50 microns and having substantially no intrinsic strength and a winding wound on said magnetic core, the casing supplying the strength for supporting the winding and the core.
2. An antenna as claimed in claim 1 wherein said magnetic core is of a magnetic metal and has at least one gap therein extending the length of said core parallel to the longitudinal axis thereof.
3. An antenna as claimed in claim 1 wherein said thin layer is a thin sheet of magnetic metal wrapped around said casing a plurality of times the total thickness of the layer being less than 50 microns.
4. The combination as claimed in claim 1 in which said thin layer is a single layer of magnetic material.
5. The combination as claimed in claim 1 in which said thin layer is a plurality of thicknesses of magnetic material having a total thickness of less than 50 microns.
6. In combination, a block of components for a receiver having at least a portion thereof in the shape of a cylinder and an antenna consisTing essentially of a magnetic core in the form of a thin layer consisting of high magnetic permeability material superposed on the cylindrical portion of said block of components, said layer having a thickness less than 50 microns and having substantially no intrinsic strength, and a winding on said magnetic core.
7. The combination as claimed in claim 6 wherein said magnetic core is of a magnetic metal and has at least one gap therein extending the length of said core parallel to the longitudinal axis thereof.
8. The combination as claimed in claim 6 wherein said thin layer is a thin sheet of magnetic metal wrapped around said block of components a plurality of times, the total thickness of the layer being less than 50 microns.
9. The combination as claimed in claim 6 in which said thin layer is a single layer of magnetic material.
10. The combination as claimed in claim 6 in which said thin layer is a plurality of thicknesses of magnetic material having a total thickness of less than 50 microns.
US3778836A 1966-12-27 1971-04-27 Magnetic antenna having a block or circuit components therein Expired - Lifetime US3778836A (en)

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Cited By (22)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4004228A (en) * 1974-04-29 1977-01-18 Integrated Electronics, Ltd. Portable transmitter
US4123756A (en) * 1976-09-24 1978-10-31 Nippon Electric Co., Ltd. Built-in miniature radio antenna
FR2528644A1 (en) * 1982-06-10 1983-12-16 Sensormatic Electronics Corp Assembly has a winding guide flow particular communication device
US4679233A (en) * 1985-08-30 1987-07-07 Motorola, Inc. Microphone
US4740794A (en) * 1986-01-03 1988-04-26 Motorola, Inc. Connectorless antenna coupler
EP0382130A2 (en) * 1989-02-10 1990-08-16 Junghans Uhren Gmbh Small radio-controlled clock with an antenna coil
EP0630068A1 (en) * 1993-06-21 1994-12-21 Raytheon Company Radar system and components therefor for transmitting an electromagnetic signal underwater
DE19854160A1 (en) * 1998-11-24 2000-06-08 Koepenick Funkwerk Gmbh Longwave radio receiver for distance remote-control has ferrite core of ferrite antenna formed as hollow body for acting as Faraday cage for receiver components inserted in its interior
US6400330B1 (en) * 2000-06-13 2002-06-04 Aisin Seiki Kabushiki Kaisha Bar antenna and method of manufacturing the same
US20040201536A1 (en) * 2003-04-08 2004-10-14 Masahiro Ohara Antenna device for vehicles and vehicle antenna system and communication system using the antenna device
WO2005086282A1 (en) * 2004-02-27 2005-09-15 Societe De Technologie Michelin Transmission and/or reception device which is intended to be mounted to a vehicle wheel and a housing for one such device
US20050237254A1 (en) * 2004-04-27 2005-10-27 Nec Tokin Corporation Coil antenna
EP1592085A1 (en) * 2004-04-27 2005-11-02 Nec Tokin Corporation Coil Antenna
US20060195036A1 (en) * 2005-02-25 2006-08-31 Hisao Nakamura Heartbeat measuring device
US7167140B2 (en) 2003-07-02 2007-01-23 Nec Tokin Corporation Coil antenna
US20070091007A1 (en) * 2005-08-04 2007-04-26 Murata Manufacturing Co., Ltd. Coil antenna
US20140057686A1 (en) * 2011-11-02 2014-02-27 Pong Research Corporation Protective cover for a wireless device
US9065169B2 (en) 2013-06-25 2015-06-23 University Of New Hampshire High frequency magnetic field antenna
US9172134B2 (en) 2008-11-06 2015-10-27 Antenna79, Inc. Protective cover for a wireless device
US9287915B2 (en) 2008-11-06 2016-03-15 Antenna79, Inc. Radiation redirecting elements for portable communication device
US20160093953A1 (en) * 2014-09-30 2016-03-31 Fujitsu Limited Frequency characteristic adjusting jig, antenna testing apparatus and antenna testing method, and loop antenna
US9472841B2 (en) 2008-11-06 2016-10-18 Antenna79, Inc. RF radiation redirection away from portable communication device user

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US1550889A (en) * 1924-09-15 1925-08-25 James A Doran Induction device and magnetic circuits for the same
US2256803A (en) * 1939-08-17 1941-09-23 Hauser Eric Antenna system for radio receiving sets
US2538525A (en) * 1947-06-10 1951-01-16 Rca Corp Metal-case portable receiver
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US3104364A (en) * 1957-05-07 1963-09-17 Porter Co Inc H K Magnetic core construction
US3153214A (en) * 1962-04-26 1964-10-13 Westinghouse Electric Corp Wound magnetic core structure for inductive apparatus
US3271718A (en) * 1962-08-06 1966-09-06 Tyco Laboratories Inc Magnetic cores for electrical devices and method of manufacture
US3372395A (en) * 1963-11-13 1968-03-05 Gen Electric Vlf antenna
US3538441A (en) * 1966-02-24 1970-11-03 Matsushita Electric Ind Co Ltd Antenna having a receiver therein

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US1550889A (en) * 1924-09-15 1925-08-25 James A Doran Induction device and magnetic circuits for the same
US2256803A (en) * 1939-08-17 1941-09-23 Hauser Eric Antenna system for radio receiving sets
US2538525A (en) * 1947-06-10 1951-01-16 Rca Corp Metal-case portable receiver
US3104364A (en) * 1957-05-07 1963-09-17 Porter Co Inc H K Magnetic core construction
DE1090140B (en) * 1957-06-26 1960-09-29 Autophon Ag Portable, an antenna comprehensive pager for paging systems
US3153214A (en) * 1962-04-26 1964-10-13 Westinghouse Electric Corp Wound magnetic core structure for inductive apparatus
US3271718A (en) * 1962-08-06 1966-09-06 Tyco Laboratories Inc Magnetic cores for electrical devices and method of manufacture
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Cited By (31)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4004228A (en) * 1974-04-29 1977-01-18 Integrated Electronics, Ltd. Portable transmitter
US4123756A (en) * 1976-09-24 1978-10-31 Nippon Electric Co., Ltd. Built-in miniature radio antenna
FR2528644A1 (en) * 1982-06-10 1983-12-16 Sensormatic Electronics Corp Assembly has a winding guide flow particular communication device
US4679233A (en) * 1985-08-30 1987-07-07 Motorola, Inc. Microphone
US4740794A (en) * 1986-01-03 1988-04-26 Motorola, Inc. Connectorless antenna coupler
EP0382130A3 (en) * 1989-02-10 1992-01-15 Junghans Uhren Gmbh Small radio-controlled clock with an antenna coil
EP0382130A2 (en) * 1989-02-10 1990-08-16 Junghans Uhren Gmbh Small radio-controlled clock with an antenna coil
EP0630068A1 (en) * 1993-06-21 1994-12-21 Raytheon Company Radar system and components therefor for transmitting an electromagnetic signal underwater
DE19854160A1 (en) * 1998-11-24 2000-06-08 Koepenick Funkwerk Gmbh Longwave radio receiver for distance remote-control has ferrite core of ferrite antenna formed as hollow body for acting as Faraday cage for receiver components inserted in its interior
US6400330B1 (en) * 2000-06-13 2002-06-04 Aisin Seiki Kabushiki Kaisha Bar antenna and method of manufacturing the same
US6965352B2 (en) * 2003-04-08 2005-11-15 Matsushita Electric Industrial Co., Ltd. Antenna device for vehicles and vehicle antenna system and communication system using the antenna device
US20040201536A1 (en) * 2003-04-08 2004-10-14 Masahiro Ohara Antenna device for vehicles and vehicle antenna system and communication system using the antenna device
US7167140B2 (en) 2003-07-02 2007-01-23 Nec Tokin Corporation Coil antenna
WO2005086282A1 (en) * 2004-02-27 2005-09-15 Societe De Technologie Michelin Transmission and/or reception device which is intended to be mounted to a vehicle wheel and a housing for one such device
US7679570B2 (en) 2004-02-27 2010-03-16 Michelin Recherche Et Technique S.A. Transmission and/or reception device which is intended to be mounted to a vehicle wheel and a housing for one such device
US20080088516A1 (en) * 2004-02-27 2008-04-17 Michelin Recherche Et Technique S.A. Transmission And/Or Reception Device Which Is Intended To Be Mounted To A Vehicle Wheel And A Housing For One Such Device
EP1592085A1 (en) * 2004-04-27 2005-11-02 Nec Tokin Corporation Coil Antenna
US20050237254A1 (en) * 2004-04-27 2005-10-27 Nec Tokin Corporation Coil antenna
US7030828B2 (en) 2004-04-27 2006-04-18 Nec Tokin Corporation Coil antenna
US20060195036A1 (en) * 2005-02-25 2006-08-31 Hisao Nakamura Heartbeat measuring device
US20070091007A1 (en) * 2005-08-04 2007-04-26 Murata Manufacturing Co., Ltd. Coil antenna
US7425929B2 (en) * 2005-08-04 2008-09-16 Murata Manufacturing Co., Ltd. Coil antenna
US9472841B2 (en) 2008-11-06 2016-10-18 Antenna79, Inc. RF radiation redirection away from portable communication device user
US9172134B2 (en) 2008-11-06 2015-10-27 Antenna79, Inc. Protective cover for a wireless device
US9287915B2 (en) 2008-11-06 2016-03-15 Antenna79, Inc. Radiation redirecting elements for portable communication device
US9350410B2 (en) 2008-11-06 2016-05-24 Antenna79, Inc. Protective cover for a wireless device
US20140057686A1 (en) * 2011-11-02 2014-02-27 Pong Research Corporation Protective cover for a wireless device
US9838060B2 (en) * 2011-11-02 2017-12-05 Antenna79, Inc. Protective cover for a wireless device
US9065169B2 (en) 2013-06-25 2015-06-23 University Of New Hampshire High frequency magnetic field antenna
US20160093953A1 (en) * 2014-09-30 2016-03-31 Fujitsu Limited Frequency characteristic adjusting jig, antenna testing apparatus and antenna testing method, and loop antenna
US9614284B2 (en) * 2014-09-30 2017-04-04 Fujitsu Limited Frequency characteristic adjusting jig, antenna testing apparatus and antenna testing method, and loop antenna

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