JP2005110154A - Antenna - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an antenna equipped with a plate-like base, an antenna circuit provided on the surface of the plate-like base, and a feeding line provided with conductors that are connected to the antenna circuit to supply power to the antenna circuit, which can be prevented from varying in frequency characteristics and directivity independently of a configuration of the extension of the feeding line extended from the antenna when the antennal is installed on an apparatus that uses the antenna. <P>SOLUTION: The antenna 1 is equipped with the plate-like base 3 formed of an insulator, the antenna circuit 3 formed on the surface of the plate-like base 5, and the feeding line 7 provided with conductors 9 and 11 which are connected to the antennal circuit 5 to supply power to the antenna circuit 5. Furthermore, the antenna 1 is equipped with a feeding line fixing conductor 13 which is provided adjacent to the antenna circuit 5 so as to fix the feeding line 7, formed of a conductive material, and electrically connected to either of the conductors 9 and 11. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an antenna, and in particular, when the antenna is installed in a device in which the antenna is used, the characteristics of the antenna are made as constant as possible regardless of the power supply line that supplies power to the antenna. About things that can be kept.

  Conventionally, a flat antenna (planar antenna) 100 fed by a feeder such as a coaxial cable 102 as shown in FIG. 12 is known (see, for example, Patent Document 1).

The flat antenna 100 can be easily formed in a small size, and therefore can be easily mounted in a small device such as a notebook personal computer 104 as shown in FIG.
JP 2003-152430 A

  For example, when the conventional antenna 100 is attached to the side of a liquid crystal display (LCD) 106 of the notebook personal computer 104 and the attached antenna 100 is operated, a coaxial cable 102 extending from the antenna 100 is used. It is necessary to route to an antenna drive circuit (not shown) or a connector (not shown).

  When the antenna 100 is installed as described above, the coaxial cable 102 is reflected in the vicinity of the metallic reflector 108 of the backlight provided on the LCD 106 as shown in FIGS. Along the plane of the plate 108, the coaxial cable 102 extends long (crawling).

  Here, the characteristics of the antenna 100 when the coaxial cable 102 is extended as shown in PS11 of FIG. 14 and when the coaxial cable 102 is extended as shown in PS13 of FIG. 15 will be described.

  FIG. 16 is a diagram showing the resonance frequency of the conventional antenna 100.

  Note that the horizontal axis of FIG. 16 indicates the frequency, and the vertical axis indicates the VSWR value (Voltage Standing Wave Ratio) of the antenna 100. The antenna 100 resonates with a bandwidth in a frequency range in which the VSWR value is lower than “2”. That is, the antenna 100 resonates in the vicinity of 2 GHz (more precisely, 2.5 GHz) and in the vicinity of 5 GHz.

  Also, a graph C indicated by a broken line in FIG. 16 shows the characteristics of the antenna 100 when the coaxial cable 102 is located at a position indicated by PS11 in FIG. 14, and a graph D indicated by a solid line in FIG. The characteristics of the antenna 100 when the coaxial cable 102 is located at the position indicated by PS13 are shown.

  Comparing the graph C and the graph D, it can be seen that the resonance frequency of the antenna 100 varies greatly depending on the form of the coaxial cable 102 being twisted.

  FIG. 17 is a diagram showing the directivity of horizontal polarization of the conventional antenna 100 in the 2 GHz band.

  A graph C indicated by a broken line in FIG. 17 shows the characteristics of the antenna 100 when the coaxial cable 102 is located at a position indicated by PS11 in FIG. 14, and a graph D indicated by a solid line in FIG. The characteristics of the antenna 100 when the coaxial cable 102 is located at the position indicated by PS13 are shown.

  Comparing the graph C and the graph D, it can be seen that the directivity of the horizontal polarization of the antenna 100 varies greatly depending on the shape of the coaxial cable 102.

  FIG. 18 is a diagram showing the directivity of vertical polarization of the conventional antenna 100 in the 2 GHz band.

  A graph C indicated by a broken line in FIG. 18 shows the characteristics of the antenna 100 when the coaxial cable 102 is located at a position indicated by PS11 in FIG. 14, and a graph D indicated by a solid line in FIG. The characteristics of the antenna 100 when the coaxial cable 102 is located at the position indicated by PS13 are shown.

  Comparing the graph C and the graph D, it can be seen that the directivity of the vertically polarized wave of the antenna 100 is slightly changed depending on the shape of the coaxial cable 102.

  FIG. 19 is a diagram showing the directivity of horizontal polarization of the conventional antenna 100 in the 5 GHz band.

  A graph C indicated by a broken line in FIG. 19 shows the characteristics of the antenna 100 when the coaxial cable 102 is located at a position indicated by PS11 in FIG. 14, and a graph D indicated by a solid line in FIG. The characteristics of the antenna 100 when the coaxial cable 102 is located at the position indicated by PS13 are shown.

  Comparing the graph C and the graph D, it can be seen that the directivity of the horizontal polarization of the antenna 100 varies greatly depending on the shape of the coaxial cable 102.

  FIG. 20 is a diagram showing the directivity of vertical polarization of the conventional antenna 100 in the 5 GHz band.

  Note that a graph C indicated by a broken line in FIG. 20 indicates the characteristics of the antenna 100 when the coaxial cable 102 is located at a position indicated by PS11 in FIG. 14, and a graph D indicated by a solid line in FIG. The characteristics of the antenna 100 when the coaxial cable 102 is located at the position indicated by PS13 are shown.

  Comparing the graph C and the graph D, it can be seen that the directivity of the horizontal polarization of the antenna 100 varies greatly depending on the shape of the coaxial cable 102.

  As described above, the conventional antenna 100 has a problem that the characteristics of the antenna 100 change depending on how the feeder line such as a coaxial cable extending from the antenna 100 is turned, that is, depending on the form of turning.

  The present invention has been made in view of the above problems, and each of the conductors is used to supply power to the antenna circuit provided on a plate-like base material, an antenna circuit provided on the surface of the base material, and the like. In the case of an antenna having a feeder line connected to an antenna circuit, when the antenna is installed in a device in which the antenna is used, the frequency characteristics and An object of the present invention is to provide an antenna that can prevent a change in directivity as much as possible.

  According to the first aspect of the present invention, in order to supply electric power to the plate-like base material made of an insulator, the antenna circuit provided on the surface of the base material, and the antenna circuit, each conductor is An antenna including a feed line connected to an antenna circuit, provided in the vicinity of the antenna circuit for fixing the feed line in the vicinity of the antenna circuit, configured by a conductor, and one of the conductors It is an antenna having a feeder fixed conductor conducted to one conductor.

  The invention according to claim 2 is the antenna according to claim 1, wherein the feeder fixed conductor is integrally provided on the base material.

  The invention according to claim 3 is the antenna according to claim 1, wherein the feeder fixed conductor is provided separately from the base material.

  According to a fourth aspect of the present invention, in the antenna according to any one of the first to third aspects, the feed line is a coaxial cable, and the feed line fixed conductor is an outer conductor of the coaxial cable. The distance between the feeder line fixed conductor and the antenna circuit is 10 mm to 30 mm, and the feeder line fixed conductor is provided when the antenna is installed in a device in which the antenna is used. The antenna is provided with a through hole for fixing the feeder fixing conductor to a highly conductive member constituting the device.

  According to the present invention, a plate-like base material, an antenna circuit provided on the surface of the base material, and a feeder line in which each conductor is connected to the antenna circuit to supply power to the antenna circuit. When the antenna is installed in a device in which the antenna is used, the frequency characteristics and directivity are prevented from changing as much as possible regardless of the extension form of the feeder line extending from the antenna. There is an effect that can be.

[First Embodiment]
FIG. 1 is a diagram showing a schematic configuration of an antenna 1 according to the first embodiment of the present invention.

  The antenna 1 is an insulator (dielectric) such as a polyimide-based resin, and includes a plate-like base 3 that is thinly formed so as to have flexibility, for example, on the surface (hymen) of the base 3. The antenna circuit 5 extends long and is thinly provided. The antenna circuit is made of a conductor such as copper, and is formed by etching, for example.

  The antenna circuit 5 is electrically connected to the respective conductors of a central conductor (inner conductor) 9 and an outer conductor 11 of a coaxial cable 7 which is an example of a feed line for supplying power to the antenna circuit 5. .

  In addition, a feeder fixed conductor 13 is integrally provided on the surface of the base material 3 (for example, the surface on which the antenna circuit 5 is provided) and in the vicinity of the antenna circuit. The feeder fixed conductor 13 is made of, for example, a conductor such as copper like the antenna circuit 5 and is formed almost simultaneously with the antenna circuit 5 by etching or the like.

  Further, the feed line fixing conductor 13 is provided to fix the coaxial cable 7 in the vicinity of the antenna circuit 5 when the antenna 1 is installed in a device such as a notebook computer using the antenna 1. It is connected to the outer conductor 11 of the coaxial cable 7 and is conductive.

  More specifically, the antenna circuit 5 is formed in, for example, a “U” shape and includes a first extending portion 5A and a second extending portion 5B that are parallel to each other. The feeder fixed conductor 13 is formed in a rectangular shape and is provided away from the antenna circuit 5 toward the second extending portion. The distance L1 between the feeder fixed conductor 13 and the antenna circuit 5 (second extending portion 5B) is, for example, 10 mm to 30 mm (preferably 20 mm).

  The coaxial cable 7 has a portion 9A of the central conductor 9 exposed by a predetermined length from the tip 7A. Following the exposure of the portion 9A of the central conductor 9, the coaxial cable 7 is interposed between the central conductor 9 and the outer conductor 11. The provided covering member 15 is exposed for a predetermined length, and following the exposure of the covering member 15, the portion 11A of the outer conductor 11 is exposed for a predetermined length.

  Further, following the exposure of the portion 11A of the outer conductor 11, a portion 17A of the sheath 17 covering the outside of the outer conductor 11 is provided with a predetermined length, and following the portion 17A of the sheath 17 The portion 11B of the outer conductor 11 is exposed by a predetermined length, and the coaxial cable 7 covered with the sheath 17 extends on the rear side (side away from the antenna circuit 5) from the portion 11B of the outer conductor 11. ing. The proximal end side of the coaxial cable 7 is connected to an antenna drive circuit (not shown).

  The part 9A is connected to the first extending part 5A at an intermediate part of the first extending part 5A, and the part 11A is connected to the second extending part 5B at an intermediate part of the second extending part 5B. The portion 11B is connected to the feeder fixed conductor 13. The above connections are made by, for example, soldering.

  When the antenna 1 is installed in a device in which the antenna 1 is used, the power supply line fixed conductor 13 is connected to the power supply line fixed conductor 13 with a highly conductive member constituting the device, for example, a notebook personal computer. A through hole 13A is provided for fixing to a backlight reflector provided in the LCD. The through hole 13A also penetrates the base material 3, and the feed line fixing conductor 13 (outer conductor 11) is formed using a fastening member such as a bolt or a rivet having conductivity with the through hole 13A. Is electrically connected to the reflector and the like.

  2 and 3 are views showing a state in which the antenna 1 is mounted (installed) in a device such as a notebook personal computer.

  The antenna circuit 5 of the antenna 1 is installed at a position slightly separated from the metallic reflector 19 of the backlight of the LCD, but the feed line fixing conductor 13 of the antenna 1 is fixed to the reflector 19 by a bolt BT1. Has been.

  2 and 3, the relative positional relationship between the base material 3 of the antenna 1 and the reflection plate 19 and the extending form of the coaxial cable 7 between the antenna circuit 5 and the feeder fixed conductor 13 are the same. However, FIG. 2 and FIG. 3 are different in the form of the coaxial cable 7 routed behind the feeder fixed conductor 13.

  That is, in FIG. 2, the rear coaxial cable 7 extends along the plane of the reflector 19 with a small meandering state as shown by PS1, whereas in FIG. 3, the rear coaxial cable 7 The cable 7 extends along the plane of the reflecting plate 19 with a large meandering as indicated by PS3.

  Next, the operation of the antenna 1 will be described.

  When the antenna 1 is installed in a device such as a laptop computer in which the antenna is used and power is supplied from the antenna drive circuit to the antenna circuit 5 via the coaxial cable 7, a current flows through the antenna circuit. A high-frequency current is also passed through the base material (a base material that also functions as a capacitor because it is formed of a dielectric) between the first extension part 5A and the second extension part 5B of the antenna circuit 5. Flows and radio waves are emitted from the antenna 1. As shown in FIG. 4, the antenna 1 can cope with resonance frequencies in two bands, a 2 GHz band and a 5 GHz band.

  In addition, the coaxial cable 7 between the antenna circuit 5 and the feeder fixed conductor 13 is fixed, and the outer conductor 11 of the coaxial cable 7 is electrically connected to the large conductive reflector 19, so that the antenna 1 emits radio waves. In such a state, the coaxial cable 7 (coaxial cable extending along the reflector 19) on the rear side of the feeder fixed conductor 13 is wound around like the PS1 and PS3 shown in FIGS. Even if the form of the antenna changes, the fluctuation of the characteristics of the antenna 1 is small.

  Here, the characteristics of the antenna 1 will be described with reference to the test results of the antenna 1 in FIGS. That is, the characteristics of the antenna 1 when the coaxial cable 7 is extended as shown by PS1 in FIG. 2 and when the coaxial cable 7 is extended as shown by PS3 in FIG. 3 will be described.

  FIG. 4 is a diagram illustrating the resonance frequency of the antenna 1.

  In FIG. 4, the horizontal axis indicates the frequency of the antenna 1 and the vertical axis indicates the VSWR value. As described above, the antenna 1 can generate a resonance frequency with a bandwidth in a frequency range in which the VSWR value is lower than “2”. That is, the antenna 1 generates a resonance frequency in the vicinity of 2 GHz (2 GHz band) and in the vicinity of 5 GHz (5 GHz band).

  4 shows the characteristics of the antenna 1 when the coaxial cable 7 is located at the position indicated by PS1 in FIG. 2, and the graph B indicated by the solid line in FIG. The characteristics of the antenna 1 when the coaxial cable 7 is located at the position indicated by PS3 are shown.

  Comparing the graph A and the graph B, it can be seen that the frequency characteristics of the antenna 1 hardly change depending on the form of the coaxial cable 7 being turned.

  FIG. 5 is a diagram illustrating the directivity of horizontal polarization of the antenna 1 in the 2 GHz band.

  5 indicates the characteristics of the antenna 1 when the coaxial cable 7 is located at the position indicated by PS1 in FIG. 2, and the graph B indicated by the solid line in FIG. The characteristics of the antenna 1 when the coaxial cable 7 is located at the position indicated by PS3 are shown.

  Comparing the graph A and the graph B, it can be seen that the directivity of the horizontally polarized wave of the antenna 1 is hardly changed depending on the form of the coaxial cable 7 being turned.

  FIG. 6 is a diagram showing the directivity of vertical polarization of the antenna 1 in the 2 GHz band.

  6 indicates the characteristics of the antenna 1 when the coaxial cable 7 is located at the position indicated by PS1 in FIG. 2, and the graph B indicated by the solid line in FIG. The characteristics of the antenna 1 when the coaxial cable 7 is located at the position indicated by PS3 are shown.

  Comparing the graph A and the graph B, it can be seen that the directivity of the vertically polarized wave of the antenna 1 is hardly changed depending on the form of the coaxial cable 7 being turned.

  FIG. 7 is a diagram showing the directivity of horizontal polarization of the antenna 1 in the 5 GHz band.

  7 indicates the characteristics of the antenna 1 when the coaxial cable 7 is located at the position indicated by PS1 in FIG. 2, and the graph B indicated by the solid line in FIG. The characteristics of the antenna 1 when the coaxial cable 7 is located at the position indicated by PS3 are shown.

  Comparing the graph A and the graph B, it can be seen that the directivity of the horizontally polarized wave of the antenna 1 is hardly changed depending on the form of the coaxial cable 7 being turned.

  FIG. 8 is a diagram showing the directivity of vertical polarization of the antenna 1 in the 5 GHz band.

  A graph A indicated by a broken line in FIG. 8 shows the characteristics of the antenna 1 when the coaxial cable 7 is located at a position indicated by PS1 in FIG. 2, and a graph B indicated by a solid line in FIG. The characteristics of the antenna 1 when the coaxial cable 7 is located at the position indicated by PS3 are shown.

  Comparing the graph A and the graph B, it can be seen that the directivity of the vertically polarized wave of the antenna 1 is hardly changed depending on the form of the coaxial cable 7 being turned.

  In the antenna 1, the coaxial cable 7 in the vicinity of the antenna circuit 5 is fixed to a large metal member (conductor) 19 such as a backlight of the LCD by the feed line fixing conductor 13, thereby driving the antenna more than the fixed portion. Even if the configuration of the routing of the coaxial cable 7 extending to the circuit side (half-antenna circuit side) changes around the metallic reflector 19, the characteristics of the antenna 1 can be maintained as shown in FIGS. There will be no major changes.

  Therefore, according to the antenna 1, when the antenna 1 is installed in a device such as a notebook computer using the antenna 1, the feeding line such as the coaxial cable 7 extending from the antenna 1 is extended. Regardless, it is possible to prevent the frequency characteristic and directivity from changing as much as possible.

  Moreover, according to the antenna 1, since the feeder fixed conductor 13 is provided integrally with the base material 3, the configuration of the antenna 1 is simplified. In addition, since the antenna circuit 5 and the feed line fixing conductor 13 can be simultaneously formed on the surface of the substrate 3 by etching or the like, the antenna 1 can be easily manufactured, and the antenna circuit 5 and the feed line fixing conductor 13 can be easily formed. It is easy to make the relative positional relationship between and accurate.

  Further, according to the antenna 1, the coaxial cable 7 is adopted, and the outer conductor (outer conductor covering the center conductor 9 through the covering material) 11 of the coaxial cable 7 is connected to the feeder fixed conductor 13. Therefore, regardless of the extension state of the coaxial cable 7 extending from the antenna 1, it is possible to more reliably prevent the frequency characteristics and directivity of the antenna 1 from changing.

  Further, the distance between the feeder line fixing conductor 13 and the antenna circuit 5 extends to the antenna driving circuit side (opposite side of the antenna circuit; opposite antenna circuit side) from the feeder line fixing conductor 13. Since it is shorter than the length of the coaxial cable 7 and is 10 mm to 20 mm, the coaxial cable 7 extending toward the non-antenna circuit side can be freely routed, and the degree of freedom of the installation mode of the antenna 1 is improved. Will improve.

  Further, since the feed line fixing conductor 13 is provided with a through hole 13A, the feed line fixing conductor 13 is made of metal using a fastener such as the through hole 13A and a bolt BT1 having conductivity. It is easy to fix to a large conductor provided in a device on which the antenna 1 is installed, such as the reflector 19 of the LCD.

[Second Embodiment]
FIG. 9 is a diagram showing a schematic configuration of an antenna 31 according to the second embodiment of the present invention.

  The antenna 31 is different from the antenna 1 according to the first embodiment in that the feed line fixing conductor 33 is provided separately from the base material 35, and the other points are almost the same as the antenna 1. Configured in the same manner and exhibiting substantially the same effect.

  The feed line fixing conductor 33 is formed in a rectangular shape with, for example, a thin plate-like copper plate or the like, and includes a through-hole 33A, like the feed line fixing conductor 13 according to the first embodiment.

  10 and 11 are diagrams showing a state in which the antenna 31 is mounted (installed) on a device such as a laptop computer. FIG. 10 corresponds to FIG. 2 and FIG. 11 corresponds to FIG. is there.

  According to the antenna 31, the feed line fixing conductor 33 is provided separately from the base material 35. Therefore, when the antenna 31 is installed, the coaxial cable 7 between the antenna circuit 5 and the feed line fixing conductor 33 is provided. The form of routing can be modified, and the antenna 1 can be installed in accordance with the space situation of the place where the antenna 1 is installed.

It is a figure which shows schematic structure of the antenna which concerns on the 1st Embodiment of this invention. It is a figure which shows the state which mounted antennas, such as a notebook computer. It is a figure which shows the state which mounted antennas, such as a notebook computer. It is a figure which shows the resonant frequency of an antenna. It is a figure which shows the directivity of the horizontal polarization of the antenna in 2 GHz band. It is a figure which shows the directivity of the vertically polarized wave of the antenna in a 2 GHz band. It is a figure which shows the directivity of the horizontal polarization of the antenna in a 5 GHz band. It is a figure which shows the directivity of the vertical polarization of the antenna in a 5 GHz band. It is a figure which shows schematic structure of the antenna which concerns on the 2nd Embodiment of this invention. It is a figure which shows the state which mounted antennas, such as a notebook computer. It is a figure which shows the state which mounted antennas, such as a notebook computer. It is a figure which shows schematic structure of the conventional antenna. It is a figure which shows the state which mounted | wore apparatus, such as a notebook personal computer, with the conventional antenna. It is a figure which shows the state which mounted the conventional antenna in apparatuses, such as a notebook personal computer. It is a figure which shows the state which mounted the conventional antenna in apparatuses, such as a notebook personal computer. It is a figure which shows the resonant frequency of the conventional antenna. It is a figure which shows the directivity of the horizontal polarization of the conventional antenna in 2 GHz band. It is a figure which shows the directivity of the vertical polarization of the conventional antenna in 2 GHz band. It is a figure which shows the directivity of the horizontal polarization of the conventional antenna in a 5 GHz band. It is a figure which shows the directivity of the vertical polarization of the conventional antenna in a 5 GHz band.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 31 Antenna 3, 35 Base material 5 Antenna circuit 7 Coaxial cable 9 Center conductor 11 Outer conductor 13, 33 Feed line fixed conductor 13A, 33A Through-hole 19 Reflector

Claims (4)

A plate-like base material made of an insulator; an antenna circuit provided on the surface of the base material; and a feeder line in which each conductor is connected to the antenna circuit to supply power to the antenna circuit; In an antenna with
In order to fix the feeder line in the vicinity of the antenna circuit, the feeder circuit has a feeder fixed conductor provided in the vicinity of the antenna circuit, made of a conductor, and conducting to one of the conductors. Characteristic antenna. The antenna according to claim 1, wherein
An antenna, wherein a feeder fixed conductor is integrally provided on the substrate. The antenna according to claim 1, wherein
An antenna, wherein a feeder fixed conductor is provided separately from the base material. The antenna according to any one of claims 1 to 3,
The feeder line is a coaxial cable,
The feeder fixed conductor is connected to the outer conductor of the coaxial cable;
The distance between the feeder fixed conductor and the antenna circuit is 10 mm to 30 mm,
The feed line fixing conductor is provided with a through hole for fixing the feed line fixing conductor to a large conductive member constituting the device when the antenna is installed in a device in which the antenna is used. An antenna characterized by the fact that

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