JP2004289578A - Mobile antenna - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To realize arranging an electronic apparatus by performing an FPC specification which is dealt with reductions of a size and a thickness, lengthening a connecting cable and maintaining antenna characteristics in a mobile antenna used for the electronic apparatus, such as a notebook-sized personal computer, a portable telephone, a PDC, etc. <P>SOLUTION: An antenna 2 having a radio wave resonator and the connector cable 3 for connecting the antenna to the connector of a portable unit body side are formed integrally at a flexible printed circuit board. A mobile antenna 1 is formed in a shielding structure in which the connecting cable 3 is impedance matched by the adhesion of a shielding member. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a mobile antenna used for an electronic device such as a notebook personal computer (PC), a mobile phone, and a PDA. More specifically, the present invention relates to reception / transmission by a mobile phone or the like, a network using a wireless LAN or Bluetooth, and peripheral electronic devices. Mobile antenna used for connection of the mobile phone.
[0002]
[Prior art]
Conventionally, notebook PCs and mobile phones require an antenna to receive and transmit information. However, due to recent demands for miniaturization and weight reduction and an increase in the size of a liquid crystal display screen, an antenna installation space is required. It is getting smaller and smaller.
[0003]
Conventionally, as the antenna, a rod-type external antenna having a whip portion and installed outside the information terminal has been generally used, but in recent years, a built-in antenna has become widespread. In addition to the inconvenience that the external rod gets in the way or breakage, this built-in antenna is used to obtain superiority in equipment design. The main reason is to reduce).
[0004]
As shown in FIG. 11, a radio wave resonance part 21 and a ground part 22 are formed by punching a thin metal plate, and a conductor connection part 23 connecting the two parts is formed as the built-in antenna. A core wire 24a of the cable 24 is connected at a feeding point 25 by soldering or the like, and a shield net wire 24b of the coaxial cable 24 is connected to a required portion 26 of the ground portion 22 by soldering. It is known that one end of the coaxial cable 24 is connected to a control unit on a printed circuit board of a device body via a connector or the like (for example, see Patent Document 1).
[0005]
[Patent Document 1]
JP-A-2003-037431 (Pages 1 to 5, FIG. 1)
[0006]
[Problems to be solved by the invention]
However, in the built-in antenna, a connection cable for connecting the antenna part and the control unit generally uses a coaxial cable which is advantageous in terms of measures against radio noise and signal attenuation. When adapting to mobile phones and notebook PCs that are becoming increasingly smaller and thinner, it becomes increasingly difficult to insert a hinge that can be folded in half. In a part where the space between them is narrowed and the space is not allowed, a thin coaxial cable may not be able to cope with the thinning. In addition, when an antenna unit is provided on the liquid crystal display unit, the connection distance to the control unit becomes longer, and if a coaxial cable is not used, measures against electromagnetic interference will be insufficient, and the reliability of signal reception and transmission will be improved. Will be spoiled. The mobile antenna according to the present invention has been proposed to solve such a problem.
[0007]
[Means for Solving the Problems]
In order to solve the above problems, the gist of the mobile antenna according to the present invention is that an antenna unit having a radio wave resonating unit and a connection cable for connecting the antenna unit to a connector of a portable device main body side include a flexible printed circuit. The connection cable is formed integrally with the substrate, and the connection cable has a shield structure in which the impedance is matched by attaching a shield member over substantially the entire length in the longitudinal direction.
[0008]
Further, a part of the connection cable in the longitudinal direction is formed into a shield structure by attaching a shield member, and the remaining portion in the longitudinal direction has a coplanar structure in which the impedance is matched without attaching the shield member. .
[0009]
Further, the shield member has a three-layer structure in which an insulating layer, a metal layer, and a conductive adhesive layer are stacked in this order, or a three-layer structure in which an insulating layer, an insulating adhesive layer, a metal layer, and a conductive adhesive layer are stacked in that order. The metal layer is a film formed by metal plating, vapor deposition, electrolytic foil, rolled foil, or paste;
The metal layer is made of Cu, Cu alloy, Ag, Al;
The insulating layer is made of any one of synthetic resin of polyimide, polyethylene terephthalate, polyphenylene sulfide, urethane, polyether sulfone, polyethylene naphthalate, or aramid;
Providing a surface mount type coaxial connector at a terminal of the connection cable;
A detachable connector for electrically connecting the ground portion of the antenna portion to the ground portion at a portion where the antenna portion stands substantially vertically from the ground portion;
Is included.
[0010]
ADVANTAGE OF THE INVENTION According to the mobile antenna which concerns on this invention, an antenna part and a connection part were formed by the flat flexible printed circuit board (henceforth FPC (Flexible Printed Circuit)), and it was thin and lightweight. Adaptable to electronic equipment, the flexibility of the connecting part allows it to be arranged in a narrow space, and furthermore, by using a connecting part having a coplanar structure in a part of the connecting part, flexibility is further exhibited. Therefore, for example, it is easy to wrap around a hinge portion of a two-fold type mobile phone, a notebook PC, or the like.
[0011]
In addition, the impedance matching of the connection unit allows an antenna unit to be provided on the liquid crystal display unit side of the two-fold type mobile phone, for example, to enable long-distance connection to the control unit on the main body side. Further, by selecting a material such as a metal layer, an insulating layer, and a conductive adhesive layer of the shield member, leakage of electromagnetic waves is reduced and electromagnetic interference is reduced.
[0012]
In a portion where the antenna portion stands substantially perpendicularly from the ground portion, a detachable connector for electrically connecting the ground portion of the antenna portion and the ground portion of the ground plane is provided, so that impedance due to skill in soldering is provided. The influence on the alignment is eliminated, the mounting work is facilitated, and the antenna replacement work is also facilitated.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
Next, a mobile antenna according to the present invention will be described with reference to the drawings. In order to facilitate understanding of the invention, portions corresponding to the conventional example will be described with the same reference numerals as in the conventional example.
[0014]
As shown in FIG. 1A, the mobile antenna 1 includes an inverted F-shaped antenna having an electric wave resonance section, and a connection cable 3 for connecting the antenna section 2 to a connector on the mobile device body side. This is formed integrally with an FPC (flexible printed circuit board). Except for the upright portion in the longitudinal direction of the connection cable 3, the impedance is matched by a shield member and shielded over substantially the entire length.
[0015]
Further, as another embodiment, as shown in FIG. 1B, the mobile antenna 1a in which the shield structure of the connection cable 3 changes on the way is also provided with an antenna unit 2 of an inverted-F antenna having a radio wave resonance unit. There is a connection cable 3 for connecting the antenna unit 2 to a connector on the portable device main body side, and this is integrally formed by an FPC (flexible printed circuit board). FIG. 1C shows a shape of a metal portion made of copper foil in the mobile antenna 1a. In FIGS. 1A and 1B, the shield member is omitted.
[0016]
As shown in FIGS. 2 (A) and 2 (B), the antenna part 2 is provided with a standing part 4 in which the antenna part 2 stands up substantially perpendicularly from a ground part 5 which is a ground plane to have a space. As an example of electrically connecting the ground section 5 to the ground section, a detachable connector (without center contact) 6 is provided.
[0017]
The connection cable 3 has a shield structure in which impedance matching is performed over substantially the entire length in the longitudinal direction (hereinafter, this is referred to as a normal type). As shown in FIG. 3, a part thereof is shielded from the lower portion of the upright portion 4 to the rear, for example, approximately half of the total length of about 150 mm and 75 mm (hereinafter, referred to as a conversion type). ).
[0018]
As shown in FIG. 4 (A), this shield member 7 is provided on an FPC constituted by an insulating cover lay 8 and a base member 10 in the shield attachment range of the connection cable 3, and electrically conductive on the upper and lower surfaces thereof. It is stuck with the adhesive 7a.
[0019]
Since the shield member 7 is stuck to the FPC and bent, sufficient flexibility is required. As shown in FIG. 4B, the shield member 7 is a film tape having a four-layer structure in which an insulating layer 7b, an insulating adhesive layer 7c, a metal layer 7d, and a conductive adhesive layer 7a are laminated in this order. Or a film tape having a three-layer structure in which an insulating layer 7b, a metal layer 7d, and a conductive adhesive layer 7a are laminated in this order as shown in FIG.
[0020]
The metal layer 7d is formed by metal plating, vapor deposition, electrolytic foil, rolled foil, or paste, and the metal layer is made of Cu (copper), Cu alloy, Ag (silver), Al (aluminum). The thickness is about 0.1 μm to 50 μm.
[0021]
Further, the insulating layer 7b is made of any one of polyimide (PI), polyethylene terephthalate (PET), polyphenylene sulfide (PPS), urethane, polyether sulfone (PES), polyethylene naphthalate (PEN), and aramid. It is made of resin and has a thickness of 5 μm to 30 μm.
[0022]
The conductive adhesive layer 7a has a metal filler made of, for example, Ag, Cu alloy, Ni (nickel) -plated Cu alloy, or Ag-plated Cu alloy inside the adhesive, and has a thickness of 5 μm. ４０40 μm.
[0023]
The coverlay 8 includes an insulating layer 8a and an insulating adhesive layer 8b, as shown in FIG. The base material 10 includes an insulating layer 10a, an adhesive layer 10b, and a metal layer 10c, as shown in FIG. 4E, or an insulating layer 10a, as shown in FIG. There is a metal layer 10c.
[0024]
As shown in FIGS. 5 and 6, the cover member 8 is partially cut away by the shield member 7 so as to expose the ground portions 2 b on both sides of the connection cable 3 along the longitudinal direction. The upper shield member 7 is electrically connected to the ground portion 2b via the conductive adhesive 7a, and the upper and lower shield members 7, 7 are bonded to each other at both ends in the short direction to be electrically connected.
[0025]
Accordingly, the signal / transmission path 2c at the center between both sides of the ground portion 2b is insulated by the coverlay 8 and the base member 10, and the ground portion 2b and the upper and lower shield members 7, 7 are connected to each other. The surroundings are shielded by coaxial specifications.
[0026]
In the conversion type mobile antenna 1a, the remaining half of the connection cable 3 in the longitudinal direction is not attached with the shield member 7 as shown in FIGS. It is a coplanar structure in which the width of the signal / transmission path 2d is increased and the impedance is matched.
[0027]
The range a in the middle of making the signal / transmission path thicker is an adjustment range for adjusting the range in which the shield member 7 is adhered by impedance matching. FIGS. 8 and 9 show cross-sectional views of the shield structure and the coplanar structure. As described above, the conversion type mobile antenna 1a has a coplanar structure in which the signal / transmission path 2c is formed into a thick signal / transmission path 2d from the middle in the connection cable 3.
[0028]
Further, as shown in FIG. 10B, a detachable surface mount type coaxial connector (similar to the connector 6 and having a center contact) is provided at the terminal of the connection cable 3 in the mobile antennas 1 and 1a. Is provided. The signal / transmission paths 2c and 2d and the signal / transmission path (not shown) on the device body side are electrically connected through the connector connection pad 2e by the center contact. Further, by connecting the outer peripheral portion of the connector, the ground portion 2b is grounded to the ground portion on the device body side.
[0029]
The normal type or conversion type mobile antennas 1 and 1a of the present invention have the above-described configuration. For example, when this is used for a two-fold type mobile phone, the antenna unit 2 and the connection cable 3 are thinned by FPC. Because they are integrated, they can be arranged in a small space. Specifically, even if the hinge portion of the frame case of the mobile phone is thinned, the connection portion of the shield structure is made into an FPC so that the connection portion can be disposed. Further, a coplanar structure is provided in a part of the connection portion. With the conversion type, the flexibility is exhibited to a higher degree, and it is easy to dispose it with an α winding or a crank.
[0030]
In addition, since the connection cable 3, which is a flat cable, has a shield structure of a coaxial structure in which impedance is matched, the influence of external noise from a liquid crystal display unit or the like can be prevented, and electromagnetic interference can be reduced. The length of the cable 3 can be made relatively long, and the cable 3 can be applied to a two-fold type mobile phone.
[0031]
Furthermore, since the connection of the flat cable to the ground plate has a connector structure, and the connection of the end portion of the flat cable has a connector structure, there is no trouble in soldering, and there is no possibility that impedance matching is changed.
[0032]
【The invention's effect】
As described above, in the mobile antenna according to the present invention, the antenna unit having the radio wave resonance unit and the connection cable for connecting the antenna unit to the connector on the side of the portable device main body are integrally formed by the flexible printed circuit board. Since the connection cable is formed and has a shield structure in which impedance is matched by sticking a shield member over substantially the entire length in the longitudinal direction, the whole is thinned into a film shape, and a two-fold type mobile phone or the like is used. The present invention has an excellent effect that the antenna unit can be arranged on the liquid crystal display unit distant from the main unit side control unit by making the connection cable relatively long.
[0033]
In the longitudinal direction of the connection cable, a part thereof is formed into a shield structure by sticking a shield member, and the remainder in the same longitudinal direction is a coplanar structure in which impedance matching is performed without sticking a shield member. In addition to the flexibility of the connection portion, the conversion type connection portion has a high degree of flexibility, and has an excellent effect that it becomes easier to wind the thinner electronic device frame around the hinge portion. Things.
[0034]
The shield member has a three-layer structure in which an insulating layer, a metal layer, and a conductive adhesive layer are stacked in this order, or a four-layer structure in which an insulating layer, an insulating adhesive layer, a metal layer, and a conductive adhesive layer are stacked in that order. Since the metal layer is a film formed of metal plating, vapor deposition, electrolytic foil, rolled foil, or paste, the metal layer is flexible and can be arranged in a narrow space. The signal is made of Cu, Cu alloy, Ag, Al, and the insulating layer is made of any one of synthetic resin of polyimide, polyethylene terephthalate, polyphenylene sulfide, urethane, polyether sulfone, polyethylene naphthalate, or aramid. Electromagnetic waves are reliably prevented from leaking out as a measure against electromagnetic wave brain damage, and radio waves from the liquid crystal display and the like are prevented.
[0035]
A terminal for the connection cable is provided with a surface-mount type coaxial connector, and a detachable portion for electrically connecting the ground portion of the antenna portion to the ground portion in a portion where the antenna portion stands substantially vertically from the ground portion. Since such a connector is provided, the assembling work of the antenna can be made more efficient, and the impedance matching can be prevented from being changed.
[Brief description of the drawings]
FIG. 1 is a perspective view (A) of a normal type mobile antenna 1 according to the present invention without a shield member, a perspective view (B) of a conversion type mobile antenna 1a without a shield member, and a perspective view of the same metal part ( C).
FIG. 2 is a schematic configuration diagram (A) and a front view (B) showing a structure of connector connection of an upright portion in the mobile antennas 1 and 1a according to the present invention.
FIG. 3 is a plan view of the entire configuration of an FPC according to the conversion type mobile antenna 1a according to the present invention.
FIG. 4 is a sectional view (A) of the connection cable 3 in the mobile antennas 1 and 1a according to the present invention, sectional views (B) and (C) of the shield member 7, and a sectional view (D) of the coverlay 8; It is sectional drawing (E) of a base material 10, (F).
FIG. 5 is a plan view of a coverlay 8 in the mobile antenna 1a according to the present invention.
FIGS. 6A and 6B are partially enlarged detailed views (A) and (B) of the mobile antennas 1 and 1a according to the present invention.
FIG. 7 is an enlarged detailed view of a portion of the mobile antenna 1a according to the present invention, which transitions from a shield structure portion to a coplanar structure portion.
FIG. 8 is a sectional view (A) taken along line XX in FIG. 1;
9 is a cross-sectional view (A) along the line YY in FIG. 1 and a cross-sectional view (B) along the line ZZ in FIG.
FIG. 10 is a plan view (A) of an end portion of a normal type or conversion type mobile antenna 1 or 1a according to the present invention, and a sectional view (B) of a state in which a connector 12 is fitted and connected to a device main body side. is there.
FIG. 11 is an explanatory diagram showing a configuration of a built-in antenna according to a conventional example.
[Explanation of symbols]
1, 1a mobile antenna, 2 antenna section,
2b ground part, 2c, 2d signal / transmission line,
2e connector connection pad,
3 connection cable, 4 standing part,
5 Ground, 6 Connector,
7 shield member, 7a conductive adhesive layer,
7b insulating layer, 7c insulating adhesive layer,
7d metal layer,
8 coverlay, 8a insulating layer,
8b insulating adhesive layer,
10 base material, 10a insulating layer,
10b adhesive layer, 10c metal layer,
12 Coaxial connector.

Claims (7)

An antenna unit having a radio wave resonating unit and a connection cable for connecting the antenna unit to a connector of the portable device main body are integrally formed on a flexible printed circuit board, and the connection cable has an impedance by sticking a shield member. The shield structure is matched,
A mobile antenna characterized by the following. In the longitudinal direction of the connection cable, a part thereof is formed into a shield structure by sticking a shield member, and the remainder in the same longitudinal direction has a coplanar structure in which impedance matching is performed without sticking the shield member.
The mobile antenna according to claim 1, wherein: A three-layer structure in which the shield member is laminated in the order of an insulating layer, a metal layer, and a conductive adhesive layer, or a four-layer structure in which an insulating layer, an insulating adhesive layer, a metal layer, and a conductive adhesive layer are laminated in this order The metal layer is a film formed of metal plating, vapor deposition, electrolytic foil, rolled foil, or paste;
The mobile antenna according to claim 1 or 2, wherein: The metal layer is made of Cu, Cu alloy, Ag, Al;
The mobile antenna according to claim 3, wherein: The insulating layer is made of any one of synthetic resin of polyimide, polyethylene terephthalate, polyphenylene sulfide, urethane, polyether sulfone, polyethylene naphthalate, or aramid;
The mobile antenna according to claim 3 or 4, wherein: Providing a surface mount type coaxial connector at the end of the connection cable,
The mobile antenna according to any one of claims 1 to 5, wherein In a portion where the antenna portion stands substantially vertically from the ground portion, a detachable connector that electrically connects the ground portion of the antenna portion and the ground portion is provided,
The mobile antenna according to claim 6, wherein:

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