JP2005110110A - Pattern antenna - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pattern antenna attaining miniaturization of the structure while maintaining and improving the characteristics of a grounding conductor. <P>SOLUTION: This pattern antenna constitutes an inverse F type antenna, and the grounding conductor 3 thereof is provided on both the surfaces of a resin substrate 1. Connection between the grounding conductors 3 is performed by a plurality of through holes 17. Also, in this pattern antenna, a microstrip line 13 for power feed is formed on the surface opposite to a planar radiation conductor 5 of the resin substrate 1. An RF module 15 is provided on the surface opposite to the conductor 5 of the resin substrate 1. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a pattern antenna constituting an inverted F antenna.

  An example of this type of conventional pattern antenna is described in Patent Document 1. In this Patent Document 1, a power supply microstrip line is formed on one side of a dielectric substrate on which a planar radiation conductor is provided, and accordingly, a ground conductor is formed on the other side of the dielectric substrate. Is formed. The connection between the planar radiation conductor and the ground conductor is made by a short-circuit pin that penetrates the dielectric substrate.

Japanese Patent Laid-Open No. 5-22018 (see paragraph [0015], FIG. 7 etc.)

  However, in the above pattern antenna, since the ground conductor portion is provided only on one side of the dielectric substrate (on the side opposite to the plane radiation conductor portion), the installation area of the ground conductor portion is limited. It is difficult to improve the characteristics.

  Further, in this configuration, since the downsizing of the antenna configuration (particularly the dielectric substrate) is directly connected to the reduction in the installation area of the ground conductor portion, it is difficult to downsize the device configuration.

  Therefore, the problem to be solved by the present invention is to provide a pattern antenna capable of reducing the size of the configuration while maintaining and improving the characteristics of the ground conductor portion.

  The means for solving the problem is a pattern antenna comprising a dielectric substrate, a ground conductor portion formed on the dielectric substrate, and an inverted F-type planar radiation conductor portion, wherein the ground conductor portion is A first grounding conductor film formed on one side of the dielectric substrate on which the planar radiating conductor is provided; and a first grounding conductor film formed on the other side opposite to the one side of the conductor substrate. And a second ground conductor film connected via a predetermined connection path.

  Preferably, the connection path is a through hole provided in the dielectric substrate.

  According to the first aspect of the present invention, the ground conductor portions are provided on both surfaces of the dielectric substrate, and the ground conductive films on both surfaces are connected to each other to form a three-dimensional ground conductor portion. In addition to improving the performance, it is possible to make the ground conductor part of a large area by making effective use of the space on the dielectric substrate and bring the characteristics of the ground conductor part closer to the ideal ground. The pattern antenna can be reduced in size while maintaining and improving the characteristics of the conductor portion.

  According to invention of Claim 2, the connection between the 1st and 2nd grounding conductor film which comprises a grounding conductor part can be easily performed by a through hole.

  1 and 2 are diagrams showing configurations on one side and the other side of a pattern antenna according to an embodiment of the present invention. As shown in FIGS. 1 and 2, the pattern antenna includes a resin substrate 1, a ground conductor portion 3 formed on the resin substrate 1, and an inverted F-type planar radiation conductor portion 5. .

  As shown in FIG. 1, the planar radiating conductor portion 5 is planarly formed by a metal film such as copper formed on one surface side surface of the resin substrate 1 by printing or the like. It comprises two branch portions 5b and 5c for power feeding.

  The main body portion 5a is provided apart from the ground conductor portion 3 and extends in parallel to the imaginary line L along the edge of the ground conductor portion 3 on the plane radiation conductor portion 5 side. The shorting branch 5b extends from one end of the main body 5a in the longitudinal direction toward the ground conductor 3 and is connected to a first ground conductor film 3a (described later) of the ground conductor 3. The power supply branch 5c extends from the end of the main body 5a toward the center side in the longitudinal direction by a predetermined dimension from the one end. A tip end portion that is a feeding end (feeding point) of the branch portion 5c for feeding is stopped at a position closer to the plane radiation conductor 5 than a virtual line L along the edge of the ground conductor portion 3. It is connected to a microstrip line 13 on the lower surface side, which will be described later, through a hole (connection path) 11.

  As shown in FIG. 2, a microstrip line 13 and an RF module 15 are provided on the other surface side surface of the resin substrate 1. The microstrip line 13 is used to connect the planar radiating conductor 5 and the RF module 15 while preventing deterioration of the antenna characteristics. The microstrip line 13 has a small line width and is formed by printing or the like on the resin substrate 1. It is comprised by metal films, such as copper formed in the surface. Since the RF module 15 is disposed closer to the ground conductor portion 3 than the virtual line L along the edge of the ground conductor portion 3, the microstrip line 13 is provided so as to cross the virtual line L. . One end of the microstrip line 13 is connected to the tip of the branch part 5 c through the through hole 11, and the other end is connected to an RF terminal (not shown) of the RF module 15.

  The RF module 15 is a module having a function of performing at least one of transmission and reception by the pattern antenna (in this embodiment, an RF module having a transmission / reception function (for example, a wireless LAN module or a Bluetooth (trademark) module), and The RF terminal is connected to the planar radiating conductor 5 via the microstrip line 13 and the through hole 11. Although not specifically shown, the ground terminal of the RF module 15 is connected via a predetermined connection path. It is connected to a second ground conductor film 3b of the ground conductor portion 3 to be described later.

  The ground conductor portion 3 includes a first ground conductor film 3 a provided on the one surface side surface of the resin substrate 1 and a second ground conductor film 3 b provided on the other surface side surface of the resin substrate 1. Each of the ground conductor films 3a and 3b is composed of a metal film such as copper formed on the surface of the resin substrate 1 by printing or the like. In the present embodiment, with reference to the viewpoint of FIG. 1 or FIG. 2, the first ground conductor film 3 a covers substantially the entire surface of the region below the virtual line L on the one surface side surface of the resin substrate 1. The second ground conductor film 3b is formed in a region below the imaginary line L on the other surface side surface of the resin substrate 1 and is divided into two on the left and right sides of the RF module 15. The first and second ground conductor films 3a and 3b are connected to each other by a plurality of through holes (connection paths) 17 arranged in the resin substrate 1 in the vicinity of the virtual line L.

  FIG. 3 is a cross-sectional view around the through hole 11 of the pattern antenna. As representatively shown in FIG. 3, through-holes 11 and 17 provided in the resin substrate 1, between the branch portion 5 c and the microstrip line 13, and between the first ground conductor film 3 a and the first The two ground conductor films 3b are electrically connected.

  FIG. 4 is a SWR characteristic diagram of the pattern antenna of FIG. 1, and FIG. 5 is a characteristic diagram showing the horizontal and vertical in-plane directivities of the pattern antenna. In the characteristic diagram of FIG. 5, white circles correspond to measurement results of horizontal plane directivity, and black circles correspond to measurement results of vertical in-plane directivity. It can be seen from the characteristic diagram of FIG. 4 that a desirable SWR characteristic is obtained. Further, it can be seen from the characteristic diagram of FIG. 5 that good characteristics are obtained on average with respect to the directivity characteristics in both the horizontal plane and the vertical plane.

  As described above, according to the present embodiment, the ground conductor portion 3 is provided on both surfaces of the resin substrate 1, and the ground conductive films 3a and 3b on both surfaces are connected to each other to form the three-dimensional ground conductor portion 3. Thus, the performance of the ground conductor portion 3 can be improved, and the ground conductor portion 3 having a large area can be formed by effectively utilizing the space on the resin substrate 1 so that the characteristics of the ground conductor portion 3 can be brought close to the ideal ground. As a result, the pattern antenna can be reduced in size while maintaining and improving the antenna performance, particularly the characteristics of the ground conductor 3.

  Further, the connection between the branch portion 5c and the microstrip line 13 and between the first ground conductor film 3a and the second ground conductor film 3b can be easily performed by the through holes 11 and 17.

  Furthermore, with the pattern antenna according to the present embodiment, it is possible to obtain on average good characteristics with respect to the directivity characteristics in both the horizontal plane and the vertical plane.

  As a modification of the present embodiment, connections between the branch portion 5c and the microstrip line 13 and between the first ground conductor film 3a and the second ground conductor film 3b are made through holes 11 and 17. Instead of this, a shorting pin or the like provided through the resin substrate 1 may be used.

It is a figure which shows the structure of the one surface side of the pattern antenna which concerns on one Embodiment of this invention. It is a figure which shows the structure of the other surface side of the pattern antenna of FIG. It is sectional drawing of the through-hole periphery of the pattern antenna of FIG. It is a SWR characteristic figure of the pattern antenna of FIG. It is a characteristic view which shows the horizontal surface and vertical in-plane directivity of the pattern antenna of FIG.

Explanation of symbols

1 Resin substrate (dielectric substrate)
DESCRIPTION OF SYMBOLS 3 Grounding conductor part 3a 1st earthing conductor film 3b 2nd earthing conductor film 5 Planar radiation | emission conductor part 5a Main body part 5b Branch part for short circuit 5c Branch part for electric power feeding 11 Through-hole (connection path)
13 Microstrip line 15 RF module 17 Through hole

Claims (2)

A pattern antenna comprising a dielectric substrate, a ground conductor portion formed on the dielectric substrate, and an inverted F-type planar radiation conductor portion,
The ground conductor portion is
A first grounding conductor film formed on one side of the dielectric substrate on which the planar radiation conductor is provided;
A second ground conductor film formed on the other surface side opposite to the one surface side of the conductor substrate and connected to the first ground conductor film through a predetermined connection path;
A pattern antenna. The pattern antenna according to claim 1,
The pattern antenna, wherein the connection path is a through hole provided in the dielectric substrate.

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