Patent Grant
7318268
The present invention relates to a flat-plate antenna for installation in an electrical apparatus such as a portable terminal or an electric appliance or on a wall or the like, and method for manufacturing the same, and more specifically, to flat-plate antenna and method for manufacturing the same for realizing thinner shape and excellent productivity, reducing labor for installation in an electrical apparatus or on a wall, and exhibiting desired antenna characteristics stably.
In recent years, except large-scale antennas for use in base station or satellite broadcasting, tendency to compactness of various kinds of antennas for use in a potable telephone or a mobile computer (hereinafter collectively referred to as “a portable terminal”) have been progressing. Especially, accompanied with tendency to compactness of portable terminal itself, an antenna for use in a portable terminal is required to solve problems of installation space and request for satisfying characteristics contradicting to restriction of antenna volume. Moreover, in a plan of domestic wireless network which has been progressing recently, problem of an antenna size has been arisen, in accordance with installation of an antenna in a personal computer or an electric appliance (hereinafter collectively referred to as “an electric appliance”) or on a wall surface within a room.
In
However, according to a conventional small-size antenna, firstly, antenna efficiency is inferior due to large dielectric loss of a ceramic dielectric. Secondly, tendency to compactness and lightweight of a potable terminal such as a note-type personal computer or a potable telephone may be obstructed due to restriction of antenna thickness due to dependence of overall antenna thickness on a ceramic dielectric thickness. Thirdly, labor for connecting a power supply line is needed during installation work of an antenna in an electrical apparatus or on a wall. Fourthly, productivity of an antenna is inferior because process for forming a cupper layer on a radiating element potion and process for connecting a chip antenna on a cupper plate are separate. Fifthly, cost of an antenna increases due to inferior productivity of an antenna and expensiveness of a ceramic dielectric.
An object of the present invention is to provide a flat-plate antenna and method for manufacturing the same for realizing thinner shape and excellent productivity, reducing labor during installation in an electrical apparatus or on a wall, and stably exhibiting desired antenna characteristics.
In accordance with this invention, there is provided a flat-plate antenna comprising a conductive flat-plate, a slit portion formed through said conductive plat-plate with width proportional to frequency band width, a radiating element portion disposed one side of said slit portion, a ground portion disposed other side of said slit portion, and a power supply line having a first conductor connected to said radiating element and a second conductor connected to said ground portion. Since connection between a power supply cable and a conductive flat-plate is formed previously, labor for connecting a power supply line during installation work of an antenna is eliminated. If a power supply line is extended along a surface of said conductive flat-plate, thin shaped antenna could be obtained.
In accordance with further example of the present invention, there is provided a flat-plate antenna comprising a conductive flat-plate, a slit portion formed through said conductive flat-plate with width proportional to frequency band width, a radiating element portion disposed one side of said slit portion, a ground portion disposed other side of said slit portion, a power supply line having a first conductor connected to said radiating element and a second conductor connected to said ground portion, and a covering substrate covering at least said conductive flat-plate. Since a conductive flat-plate is reinforced with a covering substrate, deformation of a conductive flat-plate is prevented.
In accordance with this invention, there is provided a method for manufacturing a flat-plate antenna comprising a step of forming a conductive flat-plate having a slit portion with width proportional to frequency band width, a radiating element portion disposed one side of said slit portion, and a ground portion disposed other side of said slit portion, wherein said slit portion is formed by press punching through said conductive flat-plate, and a step of connecting a first conductor of a power supply line with a part of said radiating element portion and a second conductor with a part of said ground portion. If slits are preferably formed by press punching on plural portions along length direction of a lead-frame, a plurality of conductive flat-plates could be obtained at once from a piece of lead-frame.
In accordance with further example of this invention, there is provided a method for manufacturing a flat-plate antenna comprising a step of forming a conductive flat-plate having a slit portion with width proportional to frequency band width, a radiating element portion disposed one side of said slit portion, and a ground portion disposed other side of said slit portion, wherein said slit portion is formed by press punching through a lead-frame, a step of laminating over said lead-frame with a resinous film, a step of forming a first and second connecting hole through which a part of said lead-frame of said radiating element portion is exposed, a step of press punching said laminated lead-frame including said slit portion, said radiating element portion and said ground portion, and a step of connecting a first conductor of a power supply line with a part of said radiating element portion exposed through said first connecting hole and a second conductor of a power supply line with a part of said ground portion exposed through said second connecting hole. Since a conductive flat-plate is reinforced with resinous film, deformation of a conductive flat-plate which is formed by press punching a lead-frame including a slit portion, a radiating element portion and a ground portion is prevented.
a) shows a plane view of a conventional small-size antenna.
b) shows a side view of a conventional small-size antenna.
a) shows a plane view of a flat-plate antenna according to an example of the present invention.
b) show a sectional view taken along line A-A of
c) show a sectional view taken along line B-B of
a),
A flat-plate antenna according to an example of the present invention is shown in
A covering substrate 2 is preferably formed by laminating over a surface of conductive flat-plate 1 with a resinous film. A heat resistant film such as a polyester film is preferably used as a resinous film to reinforce a conductive flat-plate 1 and to prevent deformation of it. Moreover, melting or deformation of a conductive flat-plate 1 caused by heat of solder connecting of a fine coaxial cable 3, or heat from surrounding operating apparatus can be prevented. Especially, a polyester film keeps the conductive flat-plate 1 clean for a long term by preventing defect, breakage, dirt or etc. due to its excellent heat resistant, water resistant and wear resistant. Other heat resistant films such as a polyimide film, a polyamide film or a polyphenylene-sulphide film are applicable in the present invention.
A fine coaxial cable 3 is comprising an inner conductor 30 formed by a single wire or a stranded wire having a plurality of wires, an outer conductor 31 formed on an inner conductor 30 through insulating layer, and a sheath 32 covering an outer conductor 31. Length of a fine coaxial cable 3 depends on a kind of applying electric apparatus or wall. For example, a length of a fine coaxial cable is 400 mm for use in notebook-type personal computer. If a flat-plate antenna is installed on a display, a wiring to communication module disposed back of keyboard through hinge portion is made by use of a fine coaxial cable. Electrical connections between an inner conductor 30 of a fine coaxial cable 3 and a radiating element portion 11, and between an outer conductor 31 and a ground portion 12 are made by solder 4 at a portion where impedance matching is achieved. Electrical connection may be achieved by conductive adhesives, connectors or etc. A flat cable formed by arranging a first conductor connected to the radiating element portion 11 and a second conductor connected to the ground portion 12 on a same plane may be used as a power supply line instead of a fine coaxial cable 3. By using such a flat cable, a thinner flat-plate antenna can be obtained.
A conductive flat-plate 1 according to an example of the present invention is shown in
A process for manufacturing a flat-plate antenna according to an example of the present invention is shown in
According to an example explained above, the following effects are performed.
(a) Since a conductive flat-plate is laminated with a heat resistant resinous film such as polyester film and a fine coaxial cable is extended along a surface of a conductive flat-plate, when a conductive flat-plate having 0.2 mm thickness, a fine coaxial cable having 0.8 mm diameter, and a resinous film having 0.1 mm thickness are used, a thin-type flat-plate antenna having 1.2 mm overall thickness can be obtained. Consequently, thin-type antenna become to be installed in a narrow space of a housing, installment in an electrical apparatus or on a wall easily established.
(b) Since deformation of a conductive flat-plate is prevented by laminating a conductive flat-plate with a resinous film, when a flat-plate antenna is installed in an electrical apparatus, desired antenna characteristic can be exhibited stably. Referring to
(c) Since a fine coaxial cable is previously connected to a conductive flat-plate, labor for connecting a fine coaxial cable is eliminated during installation work of a flat-plate antenna in an electric apparatus or on a wall. Further, by using a fine coaxial cable as a power supply line, wiring of a fine coaxial cable within an electrical apparatus is fulfilled freely without obstructing to other parts arranged in said electrical apparatus.
(d) Since a plurality of conductive flat-plates are obtained at once from a piece of lead-frame, productivity and cost are improved.
As described in detail above, according to the present invention, labor for connecting a power supply line during installation work of an antenna is eliminated by connecting between a power supply cable and a conductive flat-plate previously.
Further, thin shaped antenna can be obtained by extending a power supply line along a surface of a conductive flat-plate.
Further, desired antenna characteristic can be exhibited stably, because deformation of a conductive flat-plate is prevented by reinforcement of a conductive flat-plate with resinous film.
Further, obtaining a plurality of conductive flat-plates at once from a piece of lead-frame and improving productivity of a flat-plate antenna become possible by using a lead-frame as a conductive flat-plate and by press punching on plural portions along length direction of a lead-frame.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2001-344882 | Nov 2001 | JP | national |
The present application is a divisional of U.S. application Ser. No. 11/151,228, filed Jun. 14, 2005, now abandoned which is a divisional of application Ser. No. 10/280,097, filed Oct. 25, 2002, which is now U.S. Pat. No. 6,917,333, issued on Jul. 12, 2005, the entire contents of which are incorporated herein by reference.
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| Number | Date | Country | |
|---|---|---|---|
| 20070074385 A1 | Apr 2007 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 11151228 | Jun 2005 | US |
| Child | 11606939 | US | |
| Parent | 10280097 | Oct 2002 | US |
| Child | 11151228 | US |
