JP2003304111A - Antenna - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an antenna having a broad band structure and capable of reducing an antenna mounting area, and improving antenna characteristics. <P>SOLUTION: In this antenna, two flexible boards 15 and 18 are electrically connected to a dielectric board 11 and housed and arranged in a case body 10, and first connecting parts 14a and 14b locally formed on a ground pattern 13 of the dielectric substrate 11 are respectively connected to second connecting parts 17 and 20 locally formed on ground patterns 16 and 19 for adjusting respective flexible boards 15 and 18. An antenna pattern 12 on the dielectric substrate 11 is configured so as to be locally disposed like an inverse L so that the pattern length is set to be 1/4 of free space wavelength. The sizes of ground patterns 16 and 19 for adjustment are preliminarily adjusted so that the antenna band can be maximized in an assembly condition. Hence it is possible to assembly the antenna having a broad band structure in which the antenna band is maximized. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an antenna having a wide band structure mainly mounted on a mobile terminal, and more particularly to an antenna improved so that an antenna mounting area becomes small.

[0002]

2. Description of the Related Art Conventionally, as an antenna of this kind of wide band structure, for example, an antenna having a structure shown in an external perspective view of FIG. 6 can be cited. This antenna is disclosed in Japanese Patent Laid-Open No. 2001-2.
The invention relates to a wideband antenna and an array antenna device disclosed in Japanese Patent Publication No. 84946, in which approximately 70% of the length of a half wavelength of a free space wavelength is provided on the surface of a rectangular thin dielectric plate 1 extending in the lateral direction. A dipole antenna element 2 having a length of 4 and a pair of two pairs having a length of ¼ of the free space wavelength and facing each other in parallel are provided in the vicinity of both ends of the dipole antenna element 2. The strip-shaped parasitic elements 3a, 3b, 3c, 3d are arranged, and further, the input / output terminal 5 composed of a coaxial plug is arranged on the bottom of the dielectric plate 1 and the inner conductor is arranged on the back surface of the dielectric plate 1. Matched line 4
It has a structure in which it is connected to a and its outer conductor is connected to the dipole antenna element 2, and the dipole antenna element 2 and each parasitic element 3a, 3b, 3
The reflection characteristic at the antenna feeding point can be improved over a wide band by adjusting the arrangement interval between the antennas c and 3d.

Incidentally, as another known technique related to such an antenna, for example, Japanese Patent Laid-Open No. 6-22462.
1 and JP-A-11-136023, the microstrip antenna disclosed in JP-A-2000-188.
An antenna device disclosed in Japanese Patent No. 506 is cited.

[0004]

In the case of the antenna having the wide band structure shown in FIG. 6 described above, in addition to the area where the dipole antenna element is arranged on the dielectric plate, the area where the plural parasitic elements are arranged is provided. Since the antenna mounting area required for these arrangements is large, the area for mounting accessories such as other circuit components and functional components is reduced. As a result, there is a problem that the mounting area of the antenna is reduced in order to secure the mounting area of the accessory, and it is difficult to improve the antenna characteristics.

The present invention has been made to solve the above problems, and its technical problem is to provide an antenna having a wide band structure which can reduce the antenna mounting area and improve the antenna characteristics. is there.

[0006]

According to the present invention, an antenna pattern comprising conductive thin films arranged in an inverted L shape so that the pattern length is ¼ of the free space wavelength on the surface,
A ground pattern formed of a conductive thin film extending from the vicinity of the antenna pattern, and arranged on two adjacent sides of the peripheral portion of the ground pattern, and the size in the longitudinal direction is the long side of the ground pattern or A dielectric substrate having a first connection portion that is substantially the same as the short side, and an adjustment ground pattern made of a conductive thin film are provided on the surface, and the first portion is provided around the adjustment ground pattern. A plurality of flexible substrates made of a thin flexible dielectric provided with a second connection portion for electrical connection with one of the connection portions, and further comprising: Each of the two connecting portions is connected to one of the plurality of first connecting portions of the dielectric substrate so that the ground pattern and the adjusting ground pattern are electrically connected. Antenna is a structure can be obtained.

Further, according to the present invention, in the above antenna, the dielectric substrate and the plurality of flexible substrates are housed and arranged in a housing, and the plurality of flexible substrates are:
An antenna is obtained in which the adjusting ground patterns are respectively bent along the inner wall surface of the housing, and the tip portions thereof are arranged so as to extend to the back surface side of the dielectric substrate.

On the other hand, according to the present invention, an antenna pattern made of a conductive thin film arranged in an inverted L shape so that the pattern length is ¼ of the free space wavelength on the surface, and from the vicinity of the antenna pattern. A ground pattern made of a conductive thin film that is extendedly provided, a dielectric substrate having a plurality of conductive connecting pieces on the periphery of the ground pattern, and a conductive thin film ground pattern at a predetermined location on the inner wall surface. And a housing in which the ground pattern and the thin film ground pattern are electrically connected to each other by the plurality of connection pieces.

In this antenna, the thin film ground pattern is preferably formed by depositing a conductive material on the inner wall surface of the housing by vapor deposition or by coating a conductive material. Further, in these antennas, it is preferable that the plurality of connection pieces are leaf springs having flexibility that can be flexibly deployed in the housing, or spring probes having elasticity that can be deployed in the housing without bending. .

On the other hand, according to the present invention, in any one of the above antennas, the size of the adjusting ground pattern is obtained by adding the size of the ground pattern based on the result of measuring the ground size and the characteristics of the antenna band in advance. An antenna whose dimensions are optimally determined as the antenna band is obtained.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 shows the basic structure of an antenna according to one embodiment of the present invention. FIG. 1 (a) relates to a plan view in which constituent parts are disassembled, and FIG. 1 (b) is an assembly. The side view in the longitudinal direction of the state, the figure (c) relates to the side view in the lateral direction of the assembled state.

This antenna has an antenna pattern 12 made of a conductive thin film arranged in an inverted L shape so that the pattern length is ¼ of the free space wavelength on the surface, and extends from the vicinity of the antenna pattern 12. A rectangular shape made of a conductive thin film provided with two strip-shaped first connecting portions 14a and 14b provided for electrical connection at two locations on the peripheral side adjacent to each other. The dielectric substrate 11 having the ground pattern 13 and the rectangular first adjusting ground pattern 16 made of a conductive thin film are arranged on the surface, and one edge side in the longitudinal direction of the adjusting ground pattern 16 is provided. 1st connection part 14a in one place
A rectangular first flexible substrate 15 made of a thin flexible dielectric material provided with a strip-shaped second connecting portion 17 used for electrical connection with a rectangular first flexible substrate 15 made of a conductive thin film on the surface. The second adjusting ground pattern 19 is provided, and the first connecting portion 14 is provided at one position on one edge side in the longitudinal direction of the adjusting ground pattern 19.
band-shaped second connecting portion 20 provided for electrical connection with b
And a rectangular second flexible board 18 made of a thin flexible dielectric material, and further, each of these parts is provided in a rectangular box-shaped casing 10 with a second flexible board 15 and a second flexible board 18. The connecting portions 17 and 20 are connected to the respective first connecting portions 14a and 14b of the dielectric substrate 11 so that the ground pattern 13 and the adjusting ground patterns 16 and 19 are housed and arranged so as to be conductively connected. It is configured as an open structure.

FIG. 2 shows a calculation example for explaining the antenna characteristics when the size of the ground pattern 13 arranged on the dielectric substrate 11 provided in this antenna is changed. (A) relates to a calculation model, (b) relates to reflection characteristics at the antenna feeding point when the long side dimension L in the longitudinal direction of the ground pattern 13 is set to a first value (L = 90 mm), FIG. 7C shows the reflection characteristics at the antenna feeding point when the long side dimension L in the longitudinal direction of the ground pattern 13 is set to the second value (L = 120 mm), and FIG. , Showing the change of the band with respect to the change of the long side dimension L in the longitudinal direction of the ground pattern 13 including the dimension of FIG.

FIGS. 2B and 2C show that the band of the antenna fluctuates in response to the change in the size of the ground pattern 13, but this is usually the case in a portable terminal equipped with an antenna. The size of the dielectric substrate 11 or the size of the ground pattern 13 incorporated in the mobile terminal is designed because the size of the dielectric substrate 11 is designed with emphasis on incidental conditions of use such as ease of holding and pocketing. It is suggested that the size of the ground pattern 13 does not always become the optimum value (size) for identifying the band of the antenna under such a situation due to the above limitation.

Therefore, in such a case, the ground size and the characteristic of the antenna band are measured and grasped in advance, and the flexible substrate 15 is provided on the ground pattern 13 on the dielectric substrate 11 based on the band characteristic of the antenna depending on the size of the ground pattern 13. If the adjusting ground pattern 16 is additionally connected, the optimum ground size can be adjusted. For example, as shown in FIG. 2B, the long side dimension L in the longitudinal direction of the ground pattern 13 is L =
In the case of 90 mm, the band as an antenna becomes the minimum, so when additionally designing the adjusting ground pattern 16, it is possible to expand and optimize the band characteristic by adjusting so as to approach L = 120 mm. Incidentally, when the value of the long side dimension L in the longitudinal direction of the ground pattern 13 is changed in this way, L = 9 in the case of FIGS. 2B and 2C.
The reflection characteristics of the antenna feeding point including 0 mm and 120 mm are as shown in FIG. Although not shown here, if the value of the short side dimension W in the short side direction of the ground pattern 13 is changed, the band changes similarly to the case where the value of the long side is changed. By adjusting the size of the adjusting ground pattern 19 to a size that maximizes the antenna band and connecting it additionally, the band can be expanded and optimized. That is,
The dimensions of the adjustment ground patterns 16 and 19 are selected and determined so that the dimension of the ground pattern 13 is added based on the result of the measurement of the ground size and the characteristics of the antenna band in advance, and the dimension is optimum as the antenna band. It is what is done.

In any case, the adjusting ground patterns 16 and 19 additionally connected are the flexible substrates 15 and 1, respectively.
Due to the flexible nature of 8, the housing 1 for mobile terminals, etc.
It can be installed by bending along the inner wall surface (inner side surface) closest to 0.

Incidentally, the first connecting portions 14a and 14b in the ground pattern 13 of the dielectric substrate 11 and the adjusting ground patterns 16 of the flexible substrates 15 and 18,
As a specific example of the second connection portions 17 and 20 in 19, a connection structure in which soldering is directly performed, or a male type connector and a female type connector are separately provided and then mating connection is performed. A case of using a connector structure can be exemplified, but the first connecting portions 14a and 14b are arranged such that the size in the longitudinal direction is approximately the same as the long side or the short side of the ground pattern 13 [FIG. In the form shown in (c), only the size of the first connecting portion 14b in the longitudinal direction is the ground pattern 13.
It has the same dimension as the short side of. still,
The case where the number of the first connecting portions 14a and 14b in the ground pattern 13 of the dielectric substrate 11 used here, the number of the respective flexible substrates 15 and 18 and the number of the second connecting portions 17 and 20 is two has been described. However, these numbers are merely examples and can be arbitrarily changed.

In the case of the antenna according to the above-mentioned one embodiment, the area occupied by the antenna pattern 12 on the dielectric substrate 11 is small, and the first connecting portions 14a and 14b in the ground pattern 13 and the connecting portions are connected. Since the second connecting portions 17 and 20 in the adjusting ground patterns 16 and 19 of the flexible substrates 15 and 18 that are required occupy only a small area, the antenna mounting area is reduced, so that other circuit components and functions are provided. The area for mounting accessories such as parts can be enlarged. The configuration is such that the antenna characteristics can be easily improved in a smaller antenna mounting area.

FIG. 3 shows the basic structure when the arrangement of the flexible boards 15 and 18 provided in this antenna is changed. FIG. 3A shows a plan view in which the constituent parts are disassembled, FIG. 1B is a side view in the longitudinal direction in the assembled state, and FIG. 1C is a side view in the lateral direction in the assembled state.

This antenna is different from the case of the structure of the previous one embodiment in that the structure of each part is the same as that of the case 1
The flexible substrates 15 and 18 are connected to the dielectric substrate 11
It is different in that it is folded and deployed on the back side of. That is, the flexible boards 15 and 18 housed and arranged in the housing 10 here are the adjustment ground patterns 16 and 1.
9 are flexed along the inner wall surface of the housing 10 so that the tip portions thereof extend to the back surface side of the dielectric substrate 11.

Also in the antenna having such an arrangement structure, the antenna mounting area is small and the antenna characteristics are easily improved, as in the case of the previous embodiment.

FIG. 4 shows the basic structure of an antenna according to another embodiment of the present invention. FIG. 4 (a) is a plan view of the disassembled constituent parts, and FIG. 4 (b) is an assembled structure. The side view in the longitudinal direction of the state, the figure (c) relates to the side view in the lateral direction of the assembled state.

This antenna is different from the one in the previous embodiment, and instead of using the flexible substrates 15 and 18, a total of 10 leaf springs 2 which are conductive and have flexibility.
1 is used, two conductive thin film ground patterns 22 are provided on the inner wall surfaces of two adjacent housings 10, and one end of each leaf spring 21 is adjacent to the ground pattern 13 of the dielectric substrate 11. It is configured such that it is connected to equally spaced local portions near each edge side, and the other end is connected to equally spaced local portions of each thin film ground pattern 22 on the adjacent inner wall surface of the housing 10.

Specifically, in the case of this antenna, the antenna pattern 12 made of a conductive thin film arranged in an inverted L shape so that the pattern length is ¼ of the free space wavelength on the surface, and the antenna. A rectangular ground pattern 13 formed of a conductive thin film that extends from the vicinity of the pattern 12 and has a plurality of evenly-spaced local portions in the vicinity of two adjacent marginal sides for electrical connection. And a rectangular dielectric substrate 11 having a ground pattern 13 at one end.
In the two adjacent places in the vicinity of the edge side, a total of 10 leaf springs 21 having flexibility, which are conductive connecting pieces, are connected respectively to the locally spaced local parts. In the housing 10 in which two conductive thin film ground patterns 22 are spaced apart from each other on the inner wall surface, the other end of each leaf spring 21 is connected to the nearest evenly spaced local parts of each thin film ground pattern 22. (Or abut) so that each leaf spring 21 is bent and arranged along the nearest inner wall surface of the housing 10, and the ground pattern 13 and each thin film ground pattern 22 are electrically connected. The thin film ground pattern 22 is housed in the device, and the size of the thin film ground pattern 22 is adjusted in advance so that the antenna band is maximized.

The two thin film ground patterns 22 provided on the inner wall surfaces of the housing 10 adjacent to each other in this antenna 10 are formed by depositing a conductive material on the inner wall surface of the housing 10 by vapor deposition. Alternatively, it can be exemplified as a case of being formed by applying a conductive material. The ground pattern 13
Also, the form of the connection configuration of each thin film ground pattern 22 and the number of leaf springs 21 used for the connection are merely examples, and these numbers can be arbitrarily changed.

Also in the case of this antenna, the area occupied by the antenna pattern 12 on the dielectric substrate 11 is small, and moreover, there are two adjacent portions of the housing 10 and the local portions at equal intervals in the vicinity of the adjacent edge sides of the ground pattern 13. The two thin film ground patterns 22 provided on the inner wall surface are connected to the equally spaced local parts by the leaf springs 21. Since the antenna mounting area is small, other circuit parts, functional parts, etc. The area for mounting the accessory can be enlarged, and the antenna characteristics can be easily improved.

FIG. 5 shows a basic structure of an antenna according to another embodiment of the present invention. FIG. 5 (a) relates to a plan view in which constituent parts are disassembled, and FIG. 5 (b) is assembled. The side view in the longitudinal direction of the state, the figure (c) relates to the side view in the lateral direction of the assembled state.

Also in this antenna, unlike the previous embodiment, a total of 11 spring probes 23 having elasticity and conductivity are used instead of using the flexible substrates 15 and 18, and the housing 10 is Two conductive thin film ground patterns 22 are provided on the inner wall surfaces at two adjacent locations.
In addition, one end of each spring probe 23 is connected to a local portion of the dielectric substrate 11 in the vicinity of each adjacent edge side of the ground pattern 13 of the dielectric substrate 11, and the other end is adjacent to the housing 10. The inner wall surfaces of the thin film ground patterns 22 are connected to the equally spaced local portions.

Specifically, in the case of this antenna, the antenna pattern 12 made of a conductive thin film arranged in an inverted L shape so that the pattern length is ¼ of the free space wavelength on the surface, and the antenna. A rectangular ground pattern 13 formed of a conductive thin film that extends from the vicinity of the pattern 12 and has a plurality of evenly-spaced local portions in the vicinity of two adjacent marginal sides for electrical connection. And a rectangular dielectric substrate 11 having a ground pattern 13 at one end.
In the two adjacent locations of each of the two adjacent locations, each of which has a total of 11 spring probes 23, which are electrically conductive connecting pieces and are connected to the equally spaced local areas near the edge side. Housing 10 in which two conductive thin-film ground patterns 22 are arranged on the wall surface so as to be separated from each other
The other end of each spring probe 23 is connected (or abutted) to the nearest evenly spaced local parts of each thin film ground pattern 22 so that each spring probe 23 is perpendicular to the nearest inner wall surface of the housing 10. Stored and arranged so that the ground pattern 13 and each thin film ground pattern 22 are conductively connected after being arranged without being bent,
In addition, the size of the thin film ground pattern 22 is adjusted in advance so that the antenna band is maximized, and then the structure is formed as a broadband structure.

In the case of the two thin film ground patterns 22 provided on the inner wall surfaces of the housing 10 adjacent to each other in this antenna 10 as well, the conductive material is formed on the inner wall surface of the housing 10 by vapor deposition. Or a case where it is formed by applying a conductive material. The form of the connection structure of the ground pattern 13 and each thin film ground pattern 22 and the number of the spring probes 23 used for the connection are merely examples, and these numbers can be arbitrarily changed.

Also in the case of this antenna, the area occupied by the antenna pattern 12 on the dielectric substrate 11 is small, and moreover, the locally spaced near local edges of the ground pattern 13 and two adjacent areas of the housing 10. The two thin film ground patterns 22 provided on the inner wall surface are connected to the equidistant local parts by each spring probe 23. Since the antenna mounting area is small, other circuit parts, functional parts, etc. The area for mounting the accessory can be enlarged, and the antenna characteristics can be easily improved.

[0033]

As described above, according to the antenna of the present invention, it is assumed that a plurality of flexible substrates are electrically connected to the dielectric substrate in the housing and accommodated. The first connection portion provided on the peripheral portion of the ground pattern on the body substrate is connected to the second connection portion provided on the local portion of the adjustment ground pattern on the flexible substrate, and the antenna pattern on the dielectric substrate is A structure in which an inverted L-shape is locally arranged so that the pattern length is 1/4 of the free space wavelength, and the size of the adjusting ground pattern is adjusted in advance so that the antenna band is maximized in the assembled state. Or, instead of using a flexible substrate, a plurality of conductive connecting pieces are used, and a conductive thin film ground pattern is arranged on the inner wall surface of the housing.
A structure in which one end of each connection piece is connected to the evenly-spaced local portions near each edge side in the ground pattern of the dielectric substrate, and the other end is connected to each equally-spaced local portion of the thin-film ground pattern on the inner wall surface of the housing. Therefore, it becomes possible to add an adjusting ground pattern or a thin-film ground pattern to the ground pattern to change the overall ground size, and as described in FIG. 2, the antenna band changes depending on the ground size. By understanding the ground size and the characteristics of the antenna band, it is possible to optimize the antenna band by adding a ground pattern with an appropriate size. The size of the thin film ground pattern is adjusted so that Even when these configurations are applied, the antenna mounting area is small and the antenna band can be assembled as a wide band structure with the maximum antenna band. Moreover, it is possible to apply the same size housing as before and improve the antenna characteristics more than before. Will be able to do it.

[Brief description of drawings]

1A and 1B show a basic configuration of an antenna according to an embodiment of the present invention, in which FIG. 1A is a plan view in which components are disassembled, and FIG. 1B is a side view in a longitudinal direction in an assembled state. (C) relates to a side view in the lateral direction in the assembled state.

FIG. 2 shows a calculation example for explaining the antenna characteristics when the size of the ground pattern arranged on the dielectric substrate provided in the antenna shown in FIG. 1 is changed. Calculation model, (b) is the first dimension (L = 90) of the dimension of the ground pattern in the longitudinal direction.
mm) for the reflection characteristics at the antenna feed point, (c) for the reflection characteristics at the antenna feed point when the dimension of the ground pattern in the longitudinal direction is the second value (L = 120 mm), ( FIG. 3D shows the change of the band with respect to the change of the dimension in the longitudinal direction of the ground pattern including the dimensions of (b) and (c). [However, the calculation examples of (b), (c), and (d) are all results when the short side dimension W of the ground pattern is 50 mm, and the antenna band here has reflection characteristics at the antenna feeding point. Value (S11 <-5 in this calculation example)
Converted to dB or voltage standing wave ratio (VSWR), about 3.5
The frequency range is as follows. ]

FIG. 3 is a diagram showing a basic configuration when the arrangement of a flexible substrate provided in the antenna shown in FIG. 1 is changed,
(A) is a plan view of exploded components,
(B) relates to a side view in the longitudinal direction in the assembled state, and (c) relates to a side view in the lateral direction in the assembled state.

4A and 4B are diagrams showing a basic configuration of an antenna according to another embodiment of the present invention, in which FIG. 4A is a plan view in which components are disassembled, and FIG. 4B is a side view in a longitudinal direction in an assembled state. (C) relates to a side view in the lateral direction in the assembled state.

5A and 5B are views showing a basic structure of an antenna according to another embodiment of the present invention, in which FIG. 5A is a plan view in which constituent parts are disassembled, and FIG. 5B is a side view in a longitudinal direction in an assembled state. (C) relates to a side view in the lateral direction in the assembled state.

FIG. 6 is an external perspective view showing a basic configuration of a conventional antenna having a broadband structure.

[Explanation of symbols]

1 Dielectric plate 2 dipole antenna element 3a, 3b, 3c, 3d Parasitic element 4a Matched line 5 input / output terminals 10 housing 11 Dielectric substrate 12 antenna pattern 13 ground patterns 14a, 14b, 17, 20 Connection part 15,18 Flexible substrate 16, 19 Ground pattern for adjustment 21 leaf spring 22 Thin film ground pattern 23 Spring probe

Claims (7)

[Claims] 1. The pattern length on the surface is 1 / of the free space wavelength.
4, an antenna pattern made of a conductive thin film arranged in an inverted L shape so as to be 4, a ground pattern made of a conductive thin film extending from the vicinity of the antenna pattern, and the periphery of the ground pattern Of a dielectric substrate having a first connecting portion disposed on two adjacent sides of the portion and having a longitudinal size substantially the same as the long side or the short side of the ground pattern, and a conductive thin film on the surface And a second connecting portion provided for electrical connection with one of the first connecting portions is provided in the peripheral portion of the adjusting ground pattern. A plurality of flexible substrates made of different dielectrics, and the second connecting portions of the plurality of flexible substrates are respectively connected to one of the first connecting portions of the dielectric substrate. Antenna, wherein said ground pattern and the adjustment ground pattern that is structured to be electrically connected by. 2. The antenna according to claim 1, wherein the dielectric substrate and the plurality of flexible substrates are housed and arranged in a housing, and the plurality of flexible substrates each have the adjustment ground pattern. An antenna characterized in that the antenna is bent along the inner wall surface of the housing so that its tip portion extends to the back surface side of the dielectric substrate. 3. The pattern length on the surface is 1 / of the free space wavelength.
4, an antenna pattern made of a conductive thin film arranged in an inverted L shape so as to be 4, a ground pattern made of a conductive thin film extending from the vicinity of the antenna pattern, and the periphery of the ground pattern And a housing in which a conductive thin film ground pattern is provided at a predetermined location on the inner wall surface, and the ground pattern and the thin film ground in the housing. An antenna, wherein the pattern is housed and arranged so as to be electrically connected to the pattern by the plurality of connection pieces. 4. The antenna according to claim 3, wherein the thin film ground pattern is formed by depositing a conductive material on the inner wall surface of the housing by vapor deposition or by applying a conductive material. An antenna characterized by that. 5. The antenna according to claim 3 or 4, wherein the plurality of connection pieces are leaf springs having flexibility that can be bent and arranged in the housing. 6. The antenna according to claim 3 or 4, wherein the plurality of connection pieces are spring probes having elasticity that can be arranged in the housing without being bent. 7. The antenna according to claim 1 or 3, wherein the size of the adjusting ground pattern is a size obtained by adding the size of the ground pattern based on a result of measuring a ground size and a characteristic of an antenna band in advance. Is selected and determined so as to be optimum as the antenna band.