JP2003017923A - Antenna system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an antenna system that has a function of integrating an antenna and a filter with a simple configuration, a downsized dimension, a simplified manufacturing process and a low manufacturing cost. SOLUTION: A strip line electrode 18 of an input section 22 of the antenna 14 is configured to be clamped between at least two earth electrodes 24A, 24B via a dielectric layer. Concretely the 1st earth electrode 24A is formed to a part of an upper face of a dielectric substrate 12 corresponding to the strip line electrode 18, and the 2nd earth electrode 24B is formed to a part of a lower face of the dielectric substrate 12 corresponding to the strip line electrode 18. Further, a 3rd earth electrode 24C is formed to a part of a right side face 12c of the dielectric substrate 12 corresponding to the strip line electrode 18, and a 4th earth electrode 24D is formed to a part of a left side face 12d of the dielectric substrate 12 corresponding to the strip line electrode 18.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an antenna device in which an antenna pattern made of an electrode film is formed on a dielectric substrate.

[0002]

2. Description of the Related Art Conventionally, in order to miniaturize an antenna device and a communication device, for example, a large number of dielectric substrates having an antenna pattern formed by an electrode film on the surface thereof have been proposed (for example, Japanese Laid-Open Patent Publication No. Hei 10 (1999) -242242). 9-162633, JP-A-10-32413, and JP-A-10-41.
722).

Many of these antenna devices can be directly mounted on a wiring board for use, which is one of the advantages.

Further, by integrating the antenna and the band pass filter, the space of the antenna device can be saved.
There has also been proposed a device in which the number of manufacturing steps is reduced and the cost is reduced (for example, JP-A-8-181533).

[0005]

By the way, in the antenna in which the antenna and the filter are integrated, for example, a ground electrode is formed on the lower surface of a rectangular parallelepiped dielectric substrate, and a square antenna electrode is formed on the upper surface of the dielectric substrate. And a filter is built in the dielectric substrate.

However, since the filter has a plurality of resonators formed by embedding conductors in the holes formed in the dielectric substrate, the structure becomes complicated and large, and the manufacturing process becomes difficult. May be complicated.

[0007] In recent years, with the miniaturization of mobile phones, the wiring boards built in the mobile phones have tended to become smaller.
Therefore, the antenna of the mobile phone is
In many cases, the ground cannot be secured sufficiently. Usually, a method of optimizing the characteristics with a small wiring board is used, but it is unavoidable that it is easily affected by external influences.

[0008] For example, when the usage pattern is different from the optimized state of the system, such as the position of the hand holding the mobile phone or placing the mobile phone on a desk, the impedance of the antenna and the radiation pattern change greatly. There is a problem.

Further, in the mobile phone, as described above, it is often the case that the ground cannot be sufficiently secured due to the restriction of the wiring board. Therefore, there is a demand to make the ground formation area as large as possible. In this case, when the antenna device is directly mounted on the wiring board, the antenna device must be mounted near the ground.

When the antenna device is brought closer to the ground, the impedance usually fluctuates in the direction in which the radiation resistance decreases, and the function as the antenna deteriorates.

Therefore, when designing the antenna device, it is necessary to make the design less susceptible to the influence of the ground or to design in consideration of the influence of the ground.

The present invention has been made in view of the above problems, has a simple structure and has a function of integrating an antenna and a filter, downsizes the device itself, and simplifies and manufactures the manufacturing process. It is an object of the present invention to provide an antenna device that can effectively reduce the cost.

Another object of the present invention, when applied to, for example, an antenna of a mobile phone, is that the characteristics do not change depending on the usage pattern of the mobile phone, and the characteristics can be stabilized. An object is to provide an antenna device.

Another object of the present invention is to provide an antenna device which can adjust the input impedance of the antenna and can easily perform a design that is less susceptible to the influence of the ground and a design that allows for the influence of the ground. To provide.

[0015]

An antenna device according to the present invention comprises a dielectric substrate composed of one or more dielectric layers, and an antenna formed on the dielectric substrate. The part is formed in the dielectric substrate and is sandwiched by at least two ground electrodes with the dielectric layer interposed therebetween.

Since the input portion of the antenna is sandwiched between the ground electrodes, even if a small substrate is used, the area of the ground electrode can be made large and it is less likely to be affected by the outside. Therefore, even when the antenna device according to the present invention is applied to, for example, an antenna of a mobile phone, the characteristics do not change depending on the usage pattern of the mobile phone, and the characteristics can be stabilized.

In the above structure, the input portion of the antenna may be surrounded by four ground electrodes with the dielectric layer interposed therebetween. In this case, since the area of the ground electrode can be further increased, there is an effect that it is less likely to be affected by the outside.

Further, input / output terminals may be formed on the dielectric substrate, and a stripline electrode extending from the input / output terminals toward a feeding portion of the antenna may be provided as an input section of the antenna. Here, the strip line electrode may be a coaxial line.

In this case, the impedance of the antenna can be freely changed by appropriately changing the width and the extending direction of the strip line electrode, and the antenna can be connected to various transmission / reception circuit systems. Further, since the stripline electrode forming the input part of the antenna is sandwiched between at least two ground electrodes, the stripline electrode exerts a filter effect, and reduces the reception level of a signal outside the band, for example. be able to.

Further, the strip line electrode and the feeding portion of the antenna may be electrically connected to each other through a through hole formed in the dielectric substrate. This enables the stripline electrode and the rear end of the antenna to be electrically connected in the dielectric substrate, which is advantageous for downsizing the antenna device.

As described above, the antenna device according to the present invention has a simple structure and has a function of integrating the antenna and the filter, and the device itself can be downsized, the manufacturing process can be simplified, and the manufacturing cost can be reduced. It can be effective,
For example, when applied to an antenna of a mobile phone,
It is possible to stabilize the characteristics without changing the characteristics depending on the usage pattern of the mobile phone.

Further, an electrode may be formed in the through hole to form a capacitance between the through hole and the feeding portion of the antenna. In this case, since the impedance adjusting circuit is inserted and connected to the input part of the antenna, the input impedance of the antenna can be easily adjusted. Therefore, it is possible to easily perform the design in consideration of the influence of the ground.

As another structure capable of adjusting the input impedance of the antenna, a structure in which a capacitance is formed between the strip line electrode and a portion other than the feeding portion of the antenna may be adopted. Specifically, the stripline electrode may be extended to the tip side of the antenna with respect to the feeding portion of the antenna. As a result, a capacitance is formed between the antenna and the portion of the stripline electrode that is longer than the portion corresponding to the power feeding portion, and the capacitance can adjust the input impedance of the antenna.

Other configurations are such that the connection portion is electrically connected to the strip line electrode and a capacitance is formed between the connection portion and the ground electrode, or the connection portion is electrically connected to the ground electrode. However, there is a configuration in which a capacitance is formed between the connection portion and the strip line electrode. The antenna may be formed in a meander line shape.

[0025]

BEST MODE FOR CARRYING OUT THE INVENTION Some embodiments of an antenna device according to the present invention will be described below with reference to FIGS.

The antenna device 10 according to the first embodiment
As shown in FIG. 1, A has a dielectric substrate 12 formed by laminating and firing a plurality of plate-shaped dielectric layers, and an antenna 14 formed on the upper surface of the dielectric substrate 12. Is configured. The antenna 14 is formed in a meander line shape by an electrode film.

In the following description, in order to clarify the direction of the antenna device 10A, one of the surfaces of the dielectric substrate 12 will be described.
The surface of the antenna 14 on the open end side is referred to as a front end surface 12a, and the opposite surface is referred to as a rear end surface 12b.

In the antenna device 10A according to the first embodiment, as shown in FIG.
An input / output terminal 16 made of an electrode film is formed on the rear end face 12b, and the input / output terminal 16 and the rear end of the antenna 14 form a strip line electrode 18 and a through hole 20 formed in the dielectric substrate 12. It is electrically connected via. The strip line electrode 18 and the through hole 2
The input unit 22 of the antenna 14 is configured by 0. The portion of the antenna 14 to which the through hole 20 is connected becomes the power feeding portion 14a.

Specifically, the dielectric substrate 12 is formed as shown in FIG.
As shown in, the first to tenth dielectric layers S1 to S10 are laminated in this order from the top. These first to tenth dielectric layers S1 to S10 are composed of, for example, one or a plurality of layers.

Antenna 14 and strip line electrode 18
Are formed in regions on the dielectric substrate 12 that are separated from each other in a plane, the antenna 14 is formed on the upper surface of the first dielectric layer S1, and the stripline electrode 18 is
It is formed on the sixth dielectric layer S6. Further, one end 18a of the stripline electrode 18 and the feeding portion 14a of the antenna 14 are electrically connected to each other through the through holes 20 formed in the first to fifth dielectric layers S1 to S5, and the stripline electrode 18 is electrically connected. The other end and the input / output terminal 16 (see FIG.
(See) and is directly connected.

In the antenna device 10A according to the first embodiment, the strip line electrode 18 in the input section 22 is sandwiched by at least two ground electrodes 24A and 24B with a dielectric layer interposed therebetween. Has been done. Specifically, the first ground electrode 24A is formed on a portion of the upper surface of the dielectric substrate 12 corresponding to the stripline electrode 18, and the portion of the lower surface of the dielectric substrate 12 corresponding to the stripline electrode 18 is formed. A second ground electrode 24B is formed on the. Further, in the first embodiment, the third ground electrode 24C is formed on the right side surface 12c of the dielectric substrate 12 corresponding to the strip line electrode 18, and the third ground electrode 24C is formed on the left side surface 12d of the dielectric substrate 12. Of these, a fourth ground electrode 24D is formed in a portion corresponding to the stripline electrode 18.

That is, in the first embodiment, the strip line electrode 18 is surrounded by the first to fourth ground electrodes 24A to 24D via the dielectric layer.

An electrode 24E in an electrically floating state is formed on the front end face 12a of the dielectric substrate 12, and this electrode 24E is used as a ground electrode and connected to the antenna 14 via a capacitor. You may do it.

As described above, in the antenna device 10A according to the first embodiment, the input section 22 of the antenna 14 is used.
Is a ground electrode (particularly the first and second ground electrodes 24A
And 24B), the entire area of the ground electrode can be made large even if a small board is used as the circuit board, and it is less susceptible to external influences.

Therefore, even when the antenna device 10A according to the first embodiment is applied to, for example, an antenna of a mobile phone, the characteristics do not change depending on the usage of the mobile phone, and the characteristics are stabilized. Can be achieved.

In particular, in the first embodiment, the antenna 1
Since the four input portions 22 are surrounded by the four ground electrodes (first to fourth ground electrodes 24A to 24D) via the dielectric layer, the total area of the ground electrodes can be further increased. , The effect of being less likely to be affected by the outside.

Further, in the first embodiment, since the input section 22 is configured to have the stripline electrode 18 extending from the input / output terminal 16 to the feeding portion 14a of the antenna 14, the stripline electrode is formed. By appropriately changing the width of 18 and the extending direction, the antenna 1
The impedance of No. 4 can be freely changed and can be connected to various transmission / reception circuit systems.

Further, since the stripline electrode 18 constituting the input portion 22 of the antenna 14 is sandwiched between at least two ground electrodes 24A and 24B, the stripline electrode 18 exerts a filter effect, for example, The reception level of the out-of-band signal can be reduced.

Since the stripline electrode 18 and the feeding portion 14a of the antenna 14 are electrically connected to each other through the through hole 20 formed in the dielectric substrate 12, the stripline electrode 18 and the antenna are connected. It is possible to electrically connect the power feeding portion 14a of the antenna 14 within the dielectric substrate 12, which is advantageous for downsizing the antenna device 10A.

Here, two experimental examples (referred to as first and second experimental examples for convenience) are shown. First, the first experimental example is
The reflection characteristics of the antenna device 10A according to the first embodiment are measured. The measurement result is shown in FIG. It can be seen from FIG. 3 that the reflection level is attenuated by −20 dB or more at the center frequency (near 2.39 GHz), and the reflection characteristic is good.

In the second experimental example, the used band is 2.25 GH.
The gain characteristics of the comparative example and the example of z to 2.6 GHz are measured. The comparative example is configured with a normal dipole antenna, and the example has substantially the same configuration as the antenna device 10A according to the first embodiment.
The measurement results are shown in FIG. In FIG. 4, the characteristics of the example are shown by the solid line X, and the characteristics of the comparative example are shown by the broken line Y.

From the measurement results, the comparative example has a substantially flat gain characteristic over the used band of 2.25 GHz to 2.6 GHz, but in the embodiment, the center frequency (about 2.38 GHz) is a peak and It has a gain characteristic that attenuates from the frequency toward the low band and the high band. For example, in the vicinity of 2 GHz, the attenuation is about -20 dB.
From this, it is understood that the embodiment can effectively reduce the reception level of the signal component other than the used band and has the filter effect.

In the above-described first embodiment, the antenna 1
Although the shape of 4 is a meander line shape, it may be a straight strip shape like the antenna device 10Aa according to the first modification shown in FIG. Further, in the example of FIG. 1, the antenna 14 is formed on the upper surface of the dielectric substrate 12, but in addition, as in the antenna device 10Ab according to the second modification shown in FIG. It may be formed in the substrate 12. In the example of FIG. 6, the strip line electrode 18 and the antenna 14 are formed on the same plane, and the through hole 20 is omitted. Further, as in the antenna device 10Ac according to the third modification shown in FIG. 7, both the first and second ground electrodes 24A and 24B are formed in the dielectric substrate 12, and the first and second ground electrodes 24A and 24B are formed. The ground electrodes 24A and 24B may be short-circuited by, for example, the third ground electrode 24C formed on the right side surface of the dielectric substrate 12.

In the example of FIG. 1, the input / output terminal 16 is formed on the rear end face 12b of the dielectric substrate 12, and the stripline electrode 18 is formed along the longitudinal direction of the dielectric substrate 12. However, in addition, like the antenna device 10Ad according to the fourth modification shown in FIG.
6 may be formed on, for example, the right side surface 12c of the dielectric substrate 12, and the stripline electrode 18 may be formed in a substantially L shape.

Next, the antenna device 10B according to the second embodiment will be described with reference to FIGS.

As shown in FIGS. 9 and 10, the antenna device 10B according to the second embodiment has the above-described first device.
The antenna device 10A has substantially the same structure as the antenna device 10A according to the embodiment, except that the stripline electrode 18 is extended to the tip side of the antenna 14 with respect to the feeding portion 14a of the antenna 14.

Specifically, in FIG. 10, the strip line electrode 18 is an extension portion 1 extending toward the tip side of the antenna 14 with respect to the feeding portion 14a of the antenna 14.
8b. Also, the rear end portion 14b of the antenna 14 is
It is formed along the longitudinal direction of the rectangular parallelepiped dielectric substrate 12. The extension 18b of the stripline electrode 18 is formed in a position parallel to the rear end 14b of the antenna 14 and substantially overlapping in plan view.

With this configuration, the stripline electrode 1
8, the extension portion 18b and the rear end portion 1 of the antenna 14
A capacitance Ca is formed between the antenna 4 and 4b, and the input impedance of the antenna 14 can be adjusted by this capacitance Ca.

Here, one experimental example (referred to as a third experimental example for convenience) will be shown. In this third experimental example, as shown in FIG. 11, a large number of wiring boards 70 are prepared and each wiring board 70
The antenna devices SA1 to SA3 according to Examples 1 to 3 are mounted on one corner of the wiring board 7 and
A ground plate 7 having a ground electrode 72 formed on almost the entire surface
4 is attached, and a rectangular notch 76 is provided in a portion of the ground plate 74 corresponding to the antenna devices SA1 to SA3.
A sample provided with was prepared as a sample. In this case, for each sample, the distance m from the right end of the antenna devices SA1 to SA3 to the end of the notch 76 was set to 0.9 mm.

In the first embodiment, the strip line electrode 18 is one whose tip extends to the position corresponding to the feeding portion 14a of the antenna 14, that is, the one without the extension portion 18b. The second embodiment uses the strip line electrode. As the line electrode 18, one whose tip extends to a position corresponding to the center of the rear end portion 14b of the antenna 14 in the longitudinal direction is used,
In the third embodiment, as the stripline electrode 18, the tip thereof extends to a position corresponding to the base of the rear end portion 14b of the antenna 14, that is, the length of the extension portion 18b is that of the second embodiment (extension portion). ), Which has twice the length of

The experimental results are shown in FIGS. 12 and 13. 12 and 13, Example 1 is shown by a chain line A, Example 2 is shown by a broken line B, and Example 3 is shown by a solid line C.

From FIG. 12, in Example 1, the locus of the Smith chart becomes large due to the influence of the ground electrode 72, and the input impedance is a prescribed impedance (for example, 50).
Ω: indicated by point P).
On the other hand, in the second embodiment, since the stripline electrode 18 has the extension portion 18b, the rear end portion 14 of the antenna 14 is
A capacitance Ca (see FIG. 10) is formed between the same and b, whereby the locus of the Smith chart becomes smaller, and the amount of deviation of the input impedance from the specified impedance is smaller.

This can be understood also from the attenuation characteristic of FIG. That is, the resonance frequency of the second embodiment is lower than the resonance frequency of the first embodiment. This is the extension 18b of the stripline electrode 18 and the rear end 14b of the antenna 14.
It is considered that the cause is that the capacitance Ca is formed between and.

Particularly, in the third embodiment, the extension portion 18b
Is twice as long as that in the second embodiment,
The capacitance Ca formed between the extension portion 18b and the rear end portion 14b of the antenna 14 becomes large, and as a result, the locus of the Smith chart is significantly reduced and the input impedance is 5
It can be seen that it is stable with almost no deviation from 0Ω.

The adjustment of the resonance frequency, in particular, the adjustment of increasing the resonance frequency can be easily performed by shortening the length of the antenna 14 or increasing the width of the antenna 14.

As described above, in the antenna device 10B according to the second embodiment, the extension portion 18b is formed in the strip line electrode 18, so that the impedance adjusting circuit is inserted and connected to the input portion 22 of the antenna 14. The input impedance of the antenna 14 can be easily adjusted. Therefore, it is possible to easily perform a design that is less susceptible to the influence of the ground and a design that anticipates the influence of the ground.

Next, some modifications of the antenna device 10B according to the second embodiment will be described with reference to FIGS.

First, the antenna device 1 according to the first modification.
As shown in FIG. 14, 0Ba has substantially the same structure as the antenna device 10A according to the above-described first embodiment, but the through hole 20 is formed in the rear end portion 14b of the antenna 14.
The rear end 1 of the antenna 14 at its end without extending to
The difference is that an electrode 80 for forming a capacitance Cb is formed between the electrode 4 and 4b.

The antenna device 10 according to the first modification.
In Ba, the input impedance of the antenna 14 can be easily adjusted by appropriately changing the area of the electrode 80 formed at the end of the through hole 20.

Next, the antenna device 1 according to the second modification.
As shown in FIG. 15, 0Bb has substantially the same configuration as the antenna device 10A according to the first embodiment described above, but the lower end of the through hole 20 electrically connected to the stripline electrode 18 is dielectric. The difference is that the body substrate 12 is extended to the vicinity of the bottom and an electrode 82 for forming a capacitance Cc is formed between the end of the body substrate 12 and the ground electrode 24B.

The antenna device 10 according to the second modification.
In Bb, the input impedance of the antenna 14 can be easily adjusted by appropriately changing the area of the electrode 82 formed at the end of the through hole 20.

Next, the antenna device 1 according to the third modified example.
As shown in FIG. 16, 0Bc has a configuration in which the antenna device 10Ba according to the first modification and the antenna device 10Bb according to the second modification are combined. Therefore, in the antenna device 10Bc according to the third modified example, the electrodes 8 formed at both ends of the through hole 20 are not included.
By changing the areas of 0 and 82 as appropriate, the antenna 14
The input impedance of can be easily adjusted.

Next, the antenna device 1 according to the fourth modification.
As shown in FIG. 17, 0Bd has substantially the same configuration as that of the antenna device 10A according to the first embodiment described above, except that the ground electrode 24B to the stripline electrode 18B.
Through hole 84 is formed up to the vicinity of the line C, and a capacitance C is formed between the strip line electrode 18 and the end of the through hole 84.
The difference is that an electrode 86 for forming d is formed.

The antenna device 10 according to the fourth modification.
In Bd, the input impedance of the antenna 14 can be easily adjusted by appropriately changing the area of the electrode 86 formed at the end of the through hole 84.

Next, the antenna device 1 according to the fifth modification.
As shown in FIG. 18, 0Be has a configuration in which the antenna device 10Ba according to the first modification example and the antenna device 10Bd according to the fourth modification example described above are combined. Therefore, in the antenna device 10Be according to the fifth modification, the input impedance of the antenna 14 can be simplified by appropriately changing the areas of the electrodes 80 and 86 formed at the ends of the through holes 20 and 84. Can be adjusted to.

The antenna device according to the present invention is not limited to the above-mentioned embodiment, and it goes without saying that various configurations can be adopted without departing from the gist of the present invention.

[0067]

As described above, according to the antenna device of the present invention, the antenna device has a simple structure and the function of integrating the antenna and the filter, the device itself is downsized, and the manufacturing process is simplified. It is possible to effectively reduce the manufacturing cost, and further, when applied to, for example, an antenna of a mobile phone, the characteristics are not changed depending on the usage pattern of the mobile phone, and the characteristics are stabilized. You can

Further, the input impedance of the antenna can be adjusted, and it is possible to easily carry out a design that is less susceptible to the influence of the ground and a design that allows for the influence of the ground.

[Brief description of drawings]

FIG. 1 is a perspective view showing an antenna device according to a first embodiment.

FIG. 2 is an exploded perspective view showing the antenna device according to the first embodiment.

FIG. 3 is a characteristic diagram showing measurement results in a first experimental example.

FIG. 4 is a characteristic diagram showing measurement results in a second experimental example.

FIG. 5 is a perspective view showing an antenna device according to a first modification.

FIG. 6 is a perspective view showing an antenna device according to a second modification.

FIG. 7 is a perspective view showing an antenna device according to a third modification.

FIG. 8 is a perspective view showing an antenna device according to a fourth modification.

FIG. 9 is a perspective view showing an antenna device according to a second embodiment.

FIG. 10 is a vertical cross-sectional view showing an antenna device according to a second embodiment.

FIG. 11 is an explanatory diagram showing an example of an antenna device (sample) used in a third experimental example.

FIG. 12 is a Smith chart showing a measurement result of a third experimental example.

FIG. 13 is a diagram showing measurement results (attenuation characteristics) of a third experimental example.

FIG. 14 is a vertical cross-sectional view showing an antenna device according to a first modification.

FIG. 15 is a vertical cross-sectional view showing an antenna device according to a second modification.

FIG. 16 is a vertical cross-sectional view showing an antenna device according to a third modification.

FIG. 17 is a vertical cross-sectional view showing an antenna device according to a fourth modification.

FIG. 18 is a vertical sectional view showing an antenna device according to a fifth modification.

[Explanation of symbols]

10A, 10Aa-10Ad, 10B, 10Ba-10
Be ... Antenna device 12 ... Dielectric substrate 14 ... Antenna 14a ... Antenna feeding part 14b ... Antenna rear end part 16 ... Input / output terminal 18 ... Stripline electrode 18b ... Extension part 20, 84 ... Through hole 22 ... Input part 24A ... 1st earth electrode 24B ... 2nd earth electrode 24C ... 3rd earth electrode 24D ... 4th earth electrode 80, 82, 8
6 ... Electrode

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Takami Hirai             2-56, Sudacho, Mizuho-ku, Nagoya-shi, Aichi             Inside Hon insulator Co., Ltd. (72) Inventor Yasuhiko Mizutani             2-56, Sudacho, Mizuho-ku, Nagoya-shi, Aichi             Inside Hon insulator Co., Ltd. (72) Inventor Tainobu Saka             2-56, Sudacho, Mizuho-ku, Nagoya-shi, Aichi             Inside Hon insulator Co., Ltd. (72) Inventor Hitoshi Saito             664-1 Sarukubo, Saku City, Nagano Prefecture Soshin Electric Co., Ltd.             Ceremony Company Chikuma Factory F term (reference) 5J046 AA03 AB06 AB13 PA01 PA04                       QA00

Claims (10)

[Claims] 1. A dielectric substrate comprising one or more dielectric layers, and an antenna formed on the dielectric substrate, wherein an input portion of the antenna is formed in the dielectric substrate. Further, the antenna device is characterized in that it is sandwiched by at least two ground electrodes via the dielectric layer. 2. The antenna device according to claim 1, wherein the input portion of the antenna is surrounded by four ground electrodes with the dielectric layer interposed therebetween. 3. The antenna device according to claim 1, wherein an input / output terminal is formed on the dielectric substrate, and an input portion of the antenna is a strip extending from the input / output terminal toward a feeding portion of the antenna. An antenna device having a line electrode. 4. The antenna device according to claim 3, wherein the stripline electrode and the feeding portion of the antenna are electrically connected through a through hole formed in the dielectric substrate. Antenna device. 5. The antenna device according to claim 4, wherein an electrode for forming a capacitance between the through hole and the feeding portion of the antenna is formed. 6. The antenna device according to claim 3, wherein a capacitance is formed between a portion other than the feeding portion of the antenna and the strip line electrode. Antenna device. 7. The antenna device according to claim 6, wherein the stripline electrode is extended to a front end side of the antenna with respect to a feeding portion of the antenna. 8. The antenna device according to claim 3, wherein a connection part is electrically connected to the strip line electrode, and a capacitance is formed between the connection part and the ground electrode. An antenna device characterized by being present. 9. The antenna device according to claim 3, wherein a connection part is electrically connected to the ground electrode, and a capacitance is formed between the connection part and the stripline electrode. An antenna device characterized by being present. 10. The antenna device according to any one of claims 1 to 9, wherein the antenna is formed in a meander line shape.