JP2000151260A - Antenna device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize the miniaturization and high performance of electronic equipment (communication device is included) having an antenna by appropriately selecting and performing a balanced input (output) and an unbalanced input (output) in the connection of a filtering part and an antenna part. SOLUTION: This antenna device is constructed by laminating many dielectric layers S1 to S9, is also provided with a dielectric substrate 12 where at least an input-output terminal and an earth electrode are formed at its peripheral face, forms a filtering part 16 by arranging plural both end open type 1/2 wavelength resonant elements 14a and 14b in the dielectric substrate 12 in a respectively parallel manner and forms an antenna part 20 on the surface of the dielectric substrate 12. And, two electrodes 28 and 30 for input-output which are arranged at positions that are linearly symmetrical with respect to the length direction center of at least an output side resonant element 14b between the plural elements 14a and 14b are formed in the substrate 12, and the two electrodes 28 and 30 are respectively connected to balanced input-output terminals 32 and 34 of the antenna part 20.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a balanced input type antenna device such as a dipole antenna or a loop antenna.

[0002]

2. Description of the Related Art Generally, basic antenna elements include a balanced input type dipole antenna and a loop antenna, and an unbalanced input type monopole antenna and a helical antenna.

A balanced input type antenna device does not use a ground plate but has a structure in which the antenna device itself excites, and an unbalanced input type antenna device has a structure in which a ground plate is used to excite.

When an unbalanced input type antenna device is mounted on a mobile communication device and used, the housing of the communication device functions as a ground plate. Since the ground plate is not an infinite plane, there is a disadvantage that the antenna must be adjusted according to the shape and size of the housing.

[0005] On the other hand, the balanced input type antenna device is less susceptible to the effect of the housing, and has the advantage of requiring less labor for adjustment than the unbalanced input type antenna device. Further, in terms of performance, the antenna device itself is larger than an unbalanced input type antenna device which excites on the same principle, which is advantageous in terms of gain and bandwidth.

Further, in order to reduce the size of the antenna device and the size of the communication device, there have been conventionally proposed a large number of antenna substrates having an antenna pattern formed by an electrode film on the surface of a dielectric substrate (see, for example, Japanese Patent Application Laid-Open No. HEI 9-110572). 10-41722, JP-A-9-162633, JP-A-10-3
No. 2413).

[0007]

Heretofore, an unbalanced input type antenna device has hitherto been used as a high frequency band antenna device.

The reason is that the first-stage filter connected to the antenna device is of an unbalanced output type. Therefore, when a balanced input type antenna device is connected to the unbalanced output type filter, a balanced-unbalanced type is required. A balun, a converter, had to be used.

Providing a balun results in an increase in the number of components and an increase in the area occupied by the substrate, and there is a problem that it is not possible to achieve the basic requirement of miniaturization of the antenna device.

That is, at present, using an unbalanced input type antenna device is more advantageous in terms of insertion loss and cost.

However, if the balanced input type antenna device can be connected to the filter without using a balun, the advantages of the balanced input type antenna device can be fully exhibited, and the antenna device can be further improved. It is clear that miniaturization and high performance can be promoted.

The antenna devices according to various proposals in which an antenna pattern is formed on a dielectric substrate are exclusively concerned with the formation pattern of the antenna, and no problems have been raised regarding the connection of the filter.

The present invention has been made in view of such a problem, and an object thereof is to appropriately select a balanced input (output) and an unbalanced input (output) in connection between a filter and an antenna. It is an object of the present invention to provide an antenna device which can realize miniaturization and high performance of electronic devices (including communication devices) having an antenna.

[0014]

An antenna device according to the present invention includes a balanced input / output type antenna unit and a filter unit in which at least an input / output part connected to the antenna unit is a balanced input / output type. It is composed.

That is, since the input / output method of the filter section on the antenna section side is a balanced input / output method, the antenna section connected to the input / output terminal of the filter section can be a balanced input type antenna apparatus. .

As described above, in the antenna device according to the present invention, balanced input (output) and unbalanced input (output) can be appropriately selected for connection between the filter unit and the antenna unit. Electronic devices (including communication devices) can be reliably reduced in size and performance.

In the above configuration, the antenna section and the filter section may be integrated. In this case, since the antenna unit and the filter unit can be integrated without providing a balun or the like, miniaturization of the antenna device can be further promoted.

In the above structure, a dielectric substrate having a structure in which a number of dielectric layers are laminated and having at least an input / output terminal and a ground electrode formed on an outer peripheral surface thereof is provided. A plurality of open-ended half-wavelength resonance elements may be arranged in parallel in a dielectric substrate, and the antenna unit may be formed on the dielectric substrate.

In this case, the antenna section may be formed on the surface of the dielectric substrate, or may be formed inside the dielectric substrate. The antenna unit and the filter unit may be formed on the dielectric substrate in areas separated from each other in a plane.

The half-wavelength resonator used in the filter unit, which is one of the components of the antenna device according to the present invention,
Since both ends are open, it is not necessary to extend the resonator to the end of the dielectric substrate, and the resonance frequency may fluctuate due to variations in substrate dimensions due to the manufacturing process. Absent. Therefore, a high-performance antenna device can be provided.

Further, in the above structure, the plurality of 1 /
The two-wavelength resonator includes at least two input / output electrodes disposed at positions that are line-symmetric with respect to the longitudinal center of the output-side half-wavelength resonator in the dielectric substrate. The two input / output electrodes may be respectively connected to the balanced input / output terminals of the antenna unit.

That is, since the filter unit can appropriately select a balanced input (output) and an unbalanced input (output) in connection with the antenna unit, a balanced input / output type antenna is used as the antenna unit. be able to.

As described above, the filter unit, which is one of the components of the antenna device according to the present invention, obtains outputs from two electrodes symmetrically positioned with respect to the center of the half-wavelength resonator. A balanced output can be obtained. Conversely, when a signal having an opposite phase is input at a symmetrical position at the midpoint of the half-wavelength resonator, resonance can be achieved, thereby enabling balanced input.

Conventionally, in order to connect a filter and a balanced input / output type antenna element, a balun had to be added between the filter and the balanced input / output type antenna element. Since unbalanced input (output) can be appropriately selected and performed, connection with a balanced input / output type antenna unit can be performed without using extra circuit components such as a balun. This contributes to miniaturization and high performance of the antenna device.

Further, in the above configuration, the two input / output electrodes may be capacitively coupled to the half-wavelength resonator on the antenna section side, respectively, or the half-wavelength resonator on the antenna section side may be used. The respective resonators may be directly connected.

In the above structure, the filter section may overlap the adjacent half-wavelength resonator in the dielectric substrate with a dielectric layer interposed therebetween, and the adjacent half-wavelength resonator may be overlapped with the adjacent half-wavelength resonator. May be provided with a coupling adjustment electrode for capacitive coupling.

[0027] Thereby, between the coupling adjustment electrode and the half-wavelength resonator, and between the coupling adjustment electrode and another half-wavelength resonator.
Capacitors are respectively formed between the wavelength resonators. In terms of an equivalent circuit, since the combined capacitance of these capacitors is connected in parallel with the inductive coupling formed between the adjacent half-wavelength resonator, the inductive coupling degree is adjusted by the capacitance. And a filter having a desired bandwidth can be obtained.

The capacitance is adjusted by adjusting the overlapping area of the half-wavelength resonator and the coupling adjustment electrode, the distance therebetween, and / or
Alternatively, it can be easily performed by changing the relative permittivity εr of the dielectric between them.

Since the combined capacitance of the coupling adjustment electrodes is connected in parallel with the inductive coupling between the half-wave resonators, a parallel resonance circuit is provided between adjacent half-wave resonators. It is inserted and connected. Since the impedance of the parallel resonance circuit composed of the capacitance and the inductance changes from inductive to capacitive before and after the parallel resonance point, the impedance of the capacitance formed between the adjacent half-wavelength resonator and the coupling adjustment electrode is changed. By adjusting the value,
The coupling between the wavelength resonators can be inductive or capacitive.

Considering the case where the coupling between the half-wavelength resonators is made inductive, a filter having an attenuation pole on the high-frequency side is obtained because the parallel resonance point exists on the high-frequency side of the pass band. When the coupling between the half-wavelength resonators is made capacitive, a parallel resonance point exists on the low frequency side of the pass band, and a filter having an attenuation pole on the low frequency side is obtained. In this case, the attenuation characteristic of the filter can be improved.

In the above structure, a plurality of the coupling adjustment electrodes are formed, and the plurality of coupling adjustment electrodes are connected to the 1 /
The two-wavelength resonator may be formed at a position symmetrical with respect to the longitudinal center.

In this case, the influence of the displacement between the half-wavelength resonator and the junction adjustment electrode in the manufacturing process can be suppressed. Specifically, the effect of the coupling adjustment electrode is influenced by the relative position with respect to the half-wavelength resonator, but the coupling adjustment electrode is positioned at a line symmetric position with respect to the center in the longitudinal direction of the half-wavelength resonator. By forming, even if a displacement occurs in the longitudinal direction of the half-wavelength resonator, the changes in the effects of the plurality of coupling adjustment electrodes cancel each other out, and the junction adjustment with the half-wavelength resonator is performed. The effect of displacement from the electrode can be suppressed.

[0033] In the above-described configuration, the filter section may include:
An inner ground electrode may be provided on both open ends of each of the half-wavelength resonators so as to overlap with each other with a dielectric layer interposed therebetween.

In this case, the capacitance formed between the open end side of each half-wavelength resonator and the inner-layer earth electrode is also １ ／.
Since it is added to the capacitance of the parallel resonance circuit when the wavelength resonator is equivalently converted, if the resonance frequency is the same, the inductance of the parallel resonance circuit can be reduced. The length of the half-wavelength resonator (resonator length) can be further reduced, and the overall length of the filter section can be reduced.

In this case, when the facing area between the inner layer ground electrode and each half-wavelength resonator is increased to reduce the size of the filter section, the half-wavelength resonators are more strongly induced to each other. A problem arises in that the characteristics of the filter are excessively widened by coupling. However, in the present invention, since the above-described coupling adjustment electrode is provided, the filter is formed between the coupling adjustment electrode and the half-wavelength resonator. Depending on the capacitance, the absolute value of the capacitance between the half-wavelength resonators and the total susceptance constituted by the inductive coupling between the half-wavelength resonators changes. Therefore, by adjusting the value of this capacitance, the degree of coupling between the half-wavelength resonators can be adjusted, and a filter having a desired bandwidth can be obtained.

Further, even if stacking misalignment occurs in the longitudinal direction (axial direction) of the half-wavelength resonator between the half-wavelength resonator and the inner-layer ground electrode, each open end of the half-wavelength resonator may be displaced. Since the capacitance changes cancel each other, variation in the resonance frequency can be reduced.

In the above structure, the dielectric constant of the dielectric layer on which the antenna section is formed may be different from the dielectric constant of the dielectric layer on which the filter section is formed. In particular, by making the dielectric constant of the dielectric layer on which the antenna section is formed lower than the dielectric constant of the dielectric layer on which the filter section is formed, the filter section can be downsized, and at the same time, the bandwidth of the antenna section can be reduced. Reduction and reduction in gain can be effectively suppressed.

[0038]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Some embodiments of the antenna device according to the present invention will be described below with reference to FIGS. For convenience of explanation, in the antenna elements described in these figures, the left side is referred to as a left side, the right side is referred to as a right side, the near side is referred to as a front, and the depth side is referred to as a back in the drawings. .

The antenna device 10 according to the first embodiment
As shown in FIG. 1A, as shown in FIG. 1, a dielectric substrate 12 formed by laminating and firing a plurality of plate-like dielectric layers has two open-ended half-wavelength resonance elements 14a and Filter portions 16 each having a configuration in which 14b is formed in parallel
And an antenna section 20 including a dipole antenna 18 formed of an electrode film on the upper surface of the dielectric substrate 12.

Specifically, the dielectric substrate 12 is formed as shown in FIG.
As shown in the figure, the first dielectric layers S1 to ninth
Of dielectric layers S9 are stacked. These first to ninth dielectric layers S1 to S9 are composed of one or a plurality of layers.

The antenna section 20 and the filter section 16 are
On the dielectric substrate 12, they are formed in regions separated from each other in a plane. For example, in FIG. 1, the filter section 16 is formed in the left area, and the antenna section 20 is formed in the right area. Further, the antenna section 20 is formed on the upper surface of the first dielectric layer S1, and the filter section 16 is formed from the second dielectric layer S2 to the ninth dielectric layer S9.

Further, as shown in FIG.
One input / output terminal 22 is formed, for example, on the left side surface of the outer peripheral surface, and a ground electrode 24 is formed from the left side surface to the lower surface excluding the input / output terminal 22.

In the filter section 16 of the antenna device 10A according to the first embodiment, as shown in FIG. 1, two resonance elements 14a and 14a are provided on one main surface of the sixth dielectric layer S6. 14b (first and second resonance elements 14a and 14b) are formed in parallel. Both ends of these resonators 14a and 14b are open.

On one main surface of the fifth dielectric layer S5 located above the sixth dielectric layer S6, one input / output electrode 26 and two input / output electrodes (first and Two input / output electrodes 28 and 30) are formed.

The input / output electrode 26 has one end connected to the input / output terminal 2.
2 (see FIG. 2) and is capacitively coupled to the first resonance element 14a. One end of each of the first and second input / output electrodes 28 and 30 has two balanced input / output terminals (first
And the second input / output terminals 32 and 34) through through holes 36 and 38, respectively, and are formed so as to be capacitively coupled to the second resonance element 14b.

That is, the filter section 16 is electrically connected directly to the antenna section 20 by a balanced input / output method without using an additional circuit component such as a balun. Also,
It is connected to another circuit (not shown) by the unbalanced input / output method through the input / output electrode 26 on the opposite side.

On the other hand, one main surface of the second dielectric layer S2 and the other main surface of the ninth dielectric layer S9 (the lower surface of the dielectric substrate 12) extend from the left side of the dielectric substrate 12, respectively. Inner-layer ground electrodes 40 and 42 having a relatively large rectangular area are formed.

One main surface of the fourth dielectric layer S4 and one main surface of the eighth dielectric layer S8 have four inner layer grounds corresponding to both ends of the two resonance elements 14a and 14b, respectively. Electrodes, that is, a total of eight inner layer earth electrodes (first to eighth inner layer earth electrodes) 44a to 44h are formed.

In this case, the first, third, fifth, and seventh inner-layer ground electrodes 44a, 44c, 44e, and 44g face one open ends of the first and second resonance elements 14a and 14b, respectively. And the second, fourth, sixth, and eighth inner layer ground electrodes 44b, 44d, 44f, and 44h
Are formed so as to face the other open ends of the first and second resonance elements 14a and 14b.

Further, the first to fourth inner-layer ground electrodes 44a
Through 44d are through holes 46a through 4d, respectively, in the inner earth electrode 40 formed on one main surface of the second dielectric layer S2.
6d, the fifth to eighth inner earth electrodes 44e to 44h are respectively connected to the inner earth electrodes 42 formed on the other main surface of the ninth dielectric layer S9 through holes 46e to 46h. Are electrically connected via

On one main surface of the seventh dielectric layer S7, two coupling adjusting electrodes (first and second coupling electrodes) which are electrically floating with respect to the ground electrode 24, the input / output terminal 22, and the antenna section 20 are provided. Two coupling adjustment electrodes 50 and 52) are formed.

The first and second coupling adjustment electrodes 50 and 52 are composed of strip-shaped first electrode bodies 50a and 52a facing the first resonance element 14a and a second resonance element 14b.
And the second electrode main bodies 50b and 52b in the shape of strips are electrically connected to each other by the lead electrodes 50c and 52c formed therebetween.

Further, in this embodiment, the first and second
The coupling adjustment electrodes 50 and 52 of FIG.
The resonance elements 14a and 14b are formed at positions symmetrical with respect to a line m at the center in the longitudinal direction.

The antenna device 10 according to the first embodiment
A is basically configured as described above. Here, the electrical connection of each electrode will be described with reference to FIGS.

First, as shown in FIG. 2, between the open ends of the first resonance element 14a and the first, second, fifth and sixth inner-layer ground electrodes 44a, 44b, 44e and 44f. Capacitances C1 and C2 and C3 and C4 are formed, respectively, and both open ends of the second resonance element 14b and third, fourth, seventh and eighth inner-layer ground electrodes 44c, 44d,
Between 4 g and 44 h, respectively.
6 and C7 and C8 are formed.

The adjacent resonance elements 14a and 14
b are inductively coupled to each other, so that the inductance L is inserted between the adjacent resonance elements 14a and 14b on the equivalent circuit.

As shown in FIG. 3, a capacitance C9 is formed between the first resonance element 14a and the input / output electrode 26, and the second resonance element 14b and the first input / output Electrode 2
8 and between the second resonance element 14b and the second input / output electrode 30 respectively.
1 is formed.

Further, the capacitance C1 is provided between the first resonance element 14a and the first coupling adjustment electrode 50 and between the first coupling adjustment electrode 50 and the second resonance element 14b.
2 and C13 are formed, and the first resonance element 14a and the second
The capacitances C14 and C15 are formed between the second coupling adjustment electrode 52 and the second coupling adjustment electrode 52 and the second resonance element 14b, respectively.

As described above, in the antenna device 10A according to the first embodiment, a large number of dielectric layers are laminated, and at least the input / output terminals 22
And a dielectric substrate 12 on which a ground electrode 24 is formed. The filter unit 16 is configured by arranging first and second resonance elements 14a and 14b in the dielectric substrate 12 in parallel with each other. 20 is formed on the upper surface of the dielectric substrate 12.

First and second filters used in the filter unit 16
Since the resonant elements 14a and 14b are open at both ends, the first element extends to the end of the dielectric substrate 12.
In addition, there is no need to extend the second resonance elements 14a and 14b, and the resonance frequency does not vary due to variations in substrate dimensions due to the manufacturing process. Therefore, a high-performance antenna device 10A can be provided.

Further, of the first and second resonance elements 14a and 14b, at least two input / output electrodes 28 and 24 arranged at a line symmetric position with respect to the longitudinal center of the second resonance element 14b. 30 is provided in the dielectric substrate 12 and the first
And the second input / output electrodes 28 and 30
Are connected to the first and second input / output terminals 32 and 34, respectively, so that a balanced input (output) and an unbalanced input (output) can be appropriately selected and performed in connection with the antenna unit 20. As the antenna unit 20, a balanced input / output type antenna (for example, the dipole antenna 18) can be used.

As described above, the filter unit 16
By obtaining outputs from the two electrodes symmetrically positioned with respect to the center of the second and fourth resonance elements 14a and 14b, a balanced output can be obtained, and conversely, the first and second resonance elements 14a and 14b can be obtained.
When a signal having an opposite phase is input at a position symmetrical with respect to the midpoint between a and 14b, resonance can be achieved, thereby enabling balanced input.

In the prior art, a balun had to be added between the filter and the balanced input / output type antenna element. However, in this embodiment, the balanced input ( Output) and unbalanced input (output) can be selected appropriately, so that connection to the balanced input / output type antenna unit 20 can be performed without using extra circuit components such as a balun. This contributes to the downsizing and high performance of the antenna device 10A, and as a result, downsizing and high performance of electronic devices (including communication devices) having the antenna can be reliably realized.

In this embodiment, the filter portion 16 overlaps the first and second resonance elements 14a and 14b adjacent to each other in the dielectric substrate 12 with the sixth dielectric layer S6 interposed therebetween. In addition, the first and second coupling adjustment electrodes 50 and 52 for capacitively coupling the adjacent first and second resonance elements 14a and 14b are provided, so that the first and second coupling adjustment electrodes 50 are provided. And 52 and the first resonance element 14a, and between the first and second coupling adjustment electrodes 50 and 52 and the second resonance element 14b. In terms of an equivalent circuit, the combined capacitance of these capacitances is adjacent to the first and second resonance elements 14.
a and 14b are connected in parallel with the inductance L formed between them, the coupling degree can be adjusted by the capacitance, and a filter having a desired bandwidth can be obtained.

The adjustment of the capacitance is performed by the first and second resonance elements 14 a and 14 b and the first and second coupling adjustment electrodes 50.
52 and / or 52, and / or the distance between them and / or the relative dielectric constant εr of the dielectric between them can be easily changed.

The combined capacitance of the first and second coupling adjustment electrodes 50 and 52 is equal to the first and second resonance elements 14a.
And 14b, the parallel resonance circuit is inserted and connected between the adjacent first and second resonance elements 14a and 14b. Since the impedance of the parallel resonance circuit composed of the capacitance and the inductance changes from inductive to capacitive before and after the parallel resonance point, the adjacent first and second resonance elements 14a and 14b are connected to the first and second resonance elements. By adjusting the value of the capacitance formed between the coupling adjustment electrodes 50 and 52, the first and second resonance elements 14a and 14a are adjusted.
The coupling between 4b can be inductive or capacitive.

Now, considering the case where the coupling between the first and second resonance elements 14a and 14b is made inductive, since a parallel resonance point exists on the high frequency side of the pass band, an attenuation pole is provided on the high frequency side. Filter, and the first and second filters
When the coupling between the resonance elements 14a and 14b is made capacitive, a parallel resonance point exists on the low frequency side of the pass band, and a filter having an attenuation pole on the low frequency side is obtained. The filter attenuation characteristics can be improved.

Further, in this embodiment, the first and second
Are formed at positions that are line-symmetric with respect to the longitudinal centers of the first and second resonance elements 14a and 14b, so that the first and second resonance elements in the manufacturing process are formed. The influence of the displacement between 14a and 14b and the first and second joint adjustment electrodes 50 and 52 can be suppressed. Specifically, the first and second coupling adjustment electrodes 5
The effects of 0 and 52 are affected by the relative positions of the first and second resonant elements 14a and 14b, but the first and second
By forming the coupling adjustment electrodes 50 and 52 of the first and second resonance elements 14a and 14b at positions that are line-symmetric with respect to the longitudinal centers of the first and second resonance elements 14a and 14b,
Even if there is a displacement in the longitudinal direction of a and 14b,
The changes in the effects of the first and second coupling adjustment electrodes 50 and 52 cancel each other, and the first and second resonance elements 14a and 14b and the first and second junction adjustment electrodes 50 and 52 are connected to each other. The influence of the displacement can be suppressed.

In the present embodiment, the inner-layer ground electrodes 44a-44 are disposed so as to overlap the open ends of the first and second resonance elements 14a and 14b with the dielectric layer interposed therebetween.
h, the open ends of the first and second resonance elements 14a and 14b and the inner-layer ground electrode 44a
To 44h are added to the capacitance of the parallel resonance circuit when the first and second resonance elements 14a and 14b are equivalently converted, so that the resonance frequency is the same. In this case, the inductance of the parallel resonance circuit can be reduced, and as a result, the lengths (resonator lengths) of the first and second resonance elements 14a and 14b can be further reduced, and the filter section 16 The overall length can be reduced.

In this case, in order to reduce the size of the filter section 16, the inner ground electrodes 44a to 44h and the first and second inner
When the area facing the first and second resonance elements 14a and 14b is increased, the first and second resonance elements 14a and 14b are more and more strongly inductively coupled to each other, causing a problem that the filter characteristic is excessively widened. .

However, in this embodiment, since the first and second coupling adjustment electrodes 50 and 52 are provided, the first and second coupling adjustment electrodes 50 and 52 and the first And second resonance elements 14a and 14
b, the capacitance between the first and second resonance elements 14a and 14b and the total susceptance formed by the inductive coupling between the first and second resonance elements 14a and 14b. The absolute value will change.
Therefore, by adjusting the value of the capacitance, the degree of coupling between the first resonance element 14a and the second resonance element 14b can be adjusted, and a filter having a desired bandwidth can be obtained.

It is also assumed that the first and second resonance elements 14a and 14b and the inner-layer ground electrodes 44a to 44h cause a displacement in the longitudinal direction (axial direction) of the first and second resonance elements 14a and 14b. Also, the first and second resonance elements 1
Since the capacitance changes at the open ends of 4a and 14b cancel each other, it is possible to reduce the variation in the resonance frequency.

Next, some modifications of the antenna device 10A according to the first embodiment will be described with reference to FIGS. Components corresponding to those in FIG. 1 are denoted by the same reference numerals, and redundant description is omitted.

First, the antenna device 1 according to the first modified example
As shown in FIG. 5, OAa has substantially the same configuration as the antenna device 10A according to the first embodiment (see FIG. 1), but has two input / output ports on one main surface of the fifth dielectric layer S5. In that the first and second input / output electrodes 26a and 26b are formed.

In this case, the filter section 16 is connected to the antenna section 20 in a balanced input / output manner through the first and second input / output electrodes 28 and 30 on the antenna section 20 side, and the first and second electrodes on the opposite side. Are connected to other circuits (not shown) in a balanced input / output manner through the input / output electrodes 26a and 26b.

In the antenna device 10A according to the first embodiment described above, the connection end of the filter section 16 to other circuits is of an unbalanced input / output type. The antenna device 10Aa according to the first modification is The connection end of the filter section 16 with other circuits is of the balanced input / output type. In the various embodiments and various modifications of the present invention, the same applies whether the connection end of the filter section 16 to other circuits is of the balanced input / output type or the unbalanced input / output type. Therefore, in the following description of the modified examples and the embodiments, an example in which the connection end to another circuit is an unbalanced input / output method will be described, and the description of the balanced input / output method will be omitted.

Next, the antenna device 1 according to the second modification example
As shown in FIG. 6, 0Ab has substantially the same configuration as the antenna device 10A according to the first embodiment (see FIG. 1), but further includes a tenth dielectric layer on one main surface side of the first dielectric layer S1. In that the dielectric layer S10 of FIG.

That is, in the antenna device 10A according to the above-described first embodiment, the antenna unit 20 has a form exposed from the dielectric substrate 12, but in the antenna device 10Ab according to the second modification, The part 20 is provided inside the dielectric substrate 12.

Here, the antenna section 20 is connected to the dielectric substrate 12
The difference between the case in which it is formed on the surface and the case in which it is formed inside the dielectric substrate 12 will be described.

When the antenna section 20 is formed on the surface of the dielectric substrate 12, the effective permittivity is lower than when the antenna section 20 is formed inside the dielectric substrate 12. The reason is that, when the antenna section 20 is formed on the surface of the dielectric substrate 12, the effective dielectric constant is affected by air since the radiation conductor also faces air (dielectric constant = 1). Therefore, the dielectric substrate 1
2 has the antenna section 20 formed therein.
0 can be reduced in size.

However, when the dielectric substrate 12 is generally made of a material having a high dielectric constant, problems such as a decrease in the bandwidth and a decrease in the gain of the antenna section 20 occur. The dielectric constant of the dielectric to be used or the formation position of the antenna to be used is determined.

Next, the antenna device 1 according to the third modification example
As shown in FIG. 7, OAc has substantially the same configuration as the antenna device 10A according to the first embodiment (see FIG. 1), but the antenna unit 20 is provided on one main surface of the first dielectric layer S1. The difference is that the antenna section 20 is formed on one main surface of the third dielectric layer S3 without being formed.

That is, in the antenna device 10A according to the first embodiment described above, the antenna unit 20 has a configuration in which the antenna unit 20 is located above the filter unit 16.
The antenna device 10Ac according to the modified example has a configuration in which the antenna unit 20 is formed at substantially the same position as the filter unit 16. This is based on the fact that the antenna unit 20 does not necessarily need to be above the filter unit 16.

Next, an antenna device 10B according to a second embodiment will be described with reference to FIGS. Components corresponding to those in FIG. 1 are denoted by the same reference numerals, and redundant description is omitted.

As shown in FIG. 8, the antenna device 10B according to the second embodiment has almost the same configuration as the antenna device 10A according to the first embodiment (see FIG. 1). That the antenna section 20 formed on one main surface of the first dielectric layer S1 is the loop antenna 60, and the interior formed on each one main surface of the fourth dielectric layer S4 and the eighth dielectric layer S8. As shown in FIG. 9, the ground electrodes 44a to 44h are directly connected to the ground electrodes 24 formed on the front and back surfaces of the dielectric substrate 12, and the second dielectric layer S
2 in that the inner ground electrodes 40 and 42 formed on the other main surface of the ninth dielectric layer S9 and the other main surface of the ninth dielectric layer S9 are formed so as to extend to the front and back surfaces of the dielectric substrate 12.

In the antenna device 10B according to the second embodiment, similarly to the antenna device 10A according to the first embodiment, the first and second resonance elements 14a used in the filter section 16 are used. And 14b are open at both ends, so that it is not necessary to extend the resonator to the end of the dielectric substrate 12, and the resonance frequency is not affected by variations in the substrate dimensions due to the manufacturing process. There is no variation. Therefore, a high-performance antenna device 10B can be provided.

Further, of the first and second resonance elements 14a and 14b, the first and second input / output terminals arranged at positions symmetrical with respect to at least the longitudinal center of the second resonance element 14b. So that the first and second input / output electrodes 28 and 30 are connected to the first and second input / output terminals 32 and 34 of the antenna unit 20, respectively. As a result, balanced input (output) and unbalanced input (output) can be appropriately selected and performed in connection with the antenna unit 20, and the balanced input / output type antenna can be used without using extra circuit components such as a balun. A connection with the unit 20 can be made.

This contributes to the downsizing and high performance of the antenna device 10B, and thus the downsizing and high performance of electronic devices (including communication devices) having the antenna can be surely realized. .

Also in this embodiment, since the first and second coupling adjustment electrodes 50 and 52 are provided, a filter having a desired bandwidth can be obtained.

Next, some modifications of the antenna device 10B according to the second embodiment will be described with reference to FIGS.
This will be described with reference to FIG. Components corresponding to those in FIG. 8 are denoted by the same reference numerals, and the description thereof will not be repeated.

First, the antenna device 1 according to the first modification example
As shown in FIG. 10, OBa has substantially the same configuration as the antenna device 10B according to the second embodiment (see FIG. 8), but has an electrode formed on one main surface of the first dielectric layer S1. A first meandering pattern 60a of a film, a second meandering pattern 60b of an electrode film formed on one main surface of the ninth dielectric layer S9, and a right side surface of the dielectric substrate 12 as shown in FIG. And a conductor pattern 60c electrically connecting one end of the first meandering pattern 60a and one end of the second meandering pattern 60b.
(Antenna unit 20) is different.

In this case, the other end (the first input / output terminal 32) of the first meandering pattern 60a and the first input / output electrode 2
8 are electrically connected through a through hole 36, and the other end (second input / output terminal 34) of the second meandering pattern 60 b and the second input / output electrode 30 are electrically connected through the through hole 38. Connected.

In the first modification, the meandering patterns 60a and 60b are included in the loop antenna 60 (antenna section 20), so that the effective antenna length can be lengthened and the antenna section 20 can be reduced in size accordingly. Can be realized.

Next, the antenna device 1 according to the second modification example
As shown in FIG. 12, OBb has substantially the same configuration as the antenna device 10B according to the second embodiment (see FIG. 8), but the tenth main surface of the first dielectric layer S1 further includes In that the dielectric layer S10 of FIG.

That is, in the antenna device 10B according to the above-described second embodiment, the antenna section 20 has a form exposed from the dielectric substrate 12, but in the antenna device 10Bb according to the second modification, the antenna The part 20 is provided inside the dielectric substrate 12.

In this case, since the effective dielectric constant of the antenna section 20 is higher than when the antenna section 20 is formed on the surface of the dielectric substrate 12, the antenna section 20 can be downsized.

Next, the antenna device 1 according to the third modification example
As shown in FIG. 13, OBc has substantially the same configuration as the antenna device 10Ba according to the first modification (see FIG. 10), but further includes a tenth dielectric layer S1 on one main surface side. The point that the dielectric layer S10 is laminated, the eleventh dielectric layer S11 is further laminated on the other main surface side of the ninth dielectric layer S9, one end of the first meandering pattern 60a and the second The difference is that one end of the meandering pattern 60b is electrically connected to the one end of the dielectric substrate 12 through the through hole 62.

That is, in the antenna device 10Ba according to the first modified example, the antenna section 20 is
2, the antenna device 10Bc according to the third modification has the antenna unit 20 provided inside the dielectric substrate 12.

In this case, the effective dielectric constant of the antenna section 20 is higher than when the antenna section 20 is formed on the surface of the dielectric substrate 12, and the meandering patterns 60a and 60
0b increases the effective antenna length, so that the antenna section 20 can be further miniaturized.

Next, the antenna device 1 according to the fourth modification example
OBd has substantially the same configuration as the antenna device 10B according to the second embodiment (see FIG. 9) as shown in FIG.
Are formed over the upper surface, the front surface, the right side surface, and the rear surface of the dielectric substrate 12.

Also in this case, since the effective antenna length can be increased, the size of the antenna unit 20 can be reduced.

In the above-described antenna device 20B according to the second embodiment and the antenna devices 10Ba to 10Bd according to the first to fourth modified examples, an example in which the loop antenna 60 is used as the antenna unit 20 is shown. However, FIG.
As shown in FIG. 5, a dipole antenna 7 composed of a first meandering pattern 60a and a second meandering pattern 60b
0 may be used.

Also, in the antenna devices 10Ba and 10Bc according to the first and third modifications, an example is shown in which the first meandering pattern 60a and the second meandering pattern 60b are formed on different dielectric layers. However, as shown in FIG. 16, the same dielectric layer (for example, the first dielectric layer S
1 (one main surface).

Incidentally, one of the methods for reducing the size of an electronic component is as follows.
One is to use a high dielectric constant material.

In this case, a high dielectric constant material can be used for the filter section 16 without any problem. However, in the antenna section 20, as the dielectric constant of the material increases, the bandwidth of the antenna decreases. Problems such as low gain occur.

The antenna device 10C according to the third embodiment described below solves such a problem.

An antenna device 10 according to the third embodiment
C will be described with reference to FIG. FIG.
The same reference numerals are given to those corresponding to and the description thereof will not be repeated.

As shown in FIG. 17, the antenna device 10C according to the third embodiment has almost the same configuration as the antenna device 10A according to the first embodiment (see FIG. 1). 20 on which the first dielectric layer S is formed
1 is replaced by a twelfth dielectric layer S12 having a lower dielectric constant than the first to ninth dielectric layers S1 to S9, and the antenna section 20 is provided on one main surface of the twelfth dielectric layer S12. And the point that the thirteenth and fourteenth dielectric layers S13 and S14 having a low dielectric constant are laminated between the twelfth dielectric layer S12 and the second dielectric layer S2. . Of course, like the first to eleventh dielectric layers S1 to S11, the twelfth to fourteenth dielectric layers S12 to S14 each include one or more layers.

As described above, in the antenna device 10C according to the third embodiment, the dielectric layers S2 to S9 having a high dielectric constant can be used for the filter section 16, and the dielectric layer having a low dielectric constant can be used for the antenna section 20. Since the body layers S12 to S14 can be used, the size of the filter unit 16 can be reduced, and at the same time, it is possible to effectively suppress a decrease in bandwidth and a reduction in gain in the antenna unit 20.

Next, a modification of the antenna device 10C according to the third embodiment will be described with reference to FIG. Components corresponding to those in FIG. 17 are denoted by the same reference numerals, and the description thereof will not be repeated.

The antenna device 10Ca according to this modification example
Has substantially the same configuration as the antenna device 10C according to the third embodiment (see FIG. 17) as shown in FIG. 18, but has an antenna section 20 on one main surface of the thirteenth dielectric layer S13.
Is formed.

That is, in the antenna device 10C according to the third embodiment described above, the antenna unit 20 has a form exposed from the dielectric substrate 12, but in the antenna device 10Ca according to this modification, the antenna unit 20 It is in the form of being mounted on the dielectric substrate 12.

In this case, since the effective dielectric constant of the antenna section 20 is higher than when the antenna section 20 is formed on the surface of the dielectric substrate 12, the antenna section 20 can be downsized.

Next, an antenna device 10D according to a fourth embodiment will be described with reference to FIG. Components corresponding to those in FIG. 8 are denoted by the same reference numerals, and the description thereof will not be repeated.

As shown in FIG. 19, the antenna device 10D according to the fourth embodiment has substantially the same configuration as the antenna device 10B according to the second embodiment (see FIG. 8). Formed on one main surface of the dielectric layer S6 of FIG.
The input / output electrode 26 is directly connected to the resonance element 14a of
The first and second input / output electrodes 28 and 30 are formed directly on the second resonance element 14b, and the seventh dielectric layer S7 is formed on one main surface of the fifth dielectric layer S5. The difference is that third and fourth coupling adjustment electrodes 80 and 82 having the same configuration as the first and second coupling adjustment electrodes 50 and 52 are formed.

That is, in the antenna device 10D according to the fourth embodiment, the input / output terminal 22 formed on the left side of the dielectric substrate 12 and the first resonance element 14a in the dielectric substrate 12 are inserted. The first and second input / output terminals 32 and 34 of the antenna unit 20 are directly connected via the output electrode 26.
And the second resonance element 14b are directly connected via first and second input / output electrodes 28 and 30, respectively.

In the antenna device 10D according to the fourth embodiment, similarly to the antenna device 10A according to the first embodiment, the first and second resonance elements 14a used in the filter section 16 are used. Since both ends are open, the first and second resonance elements 14a and 14b do not need to be formed to extend to the end of the dielectric substrate 12, and the manufacturing process is not required. The resonance frequency does not vary due to variations in the dimensions of the substrate. Therefore, a high-performance antenna device 10D can be provided.

Further, of the first and second resonance elements 14a and 14b, the first and second input / output terminals arranged at positions symmetrical with respect to at least the longitudinal center of the second resonance element 14b. So that the first and second input / output electrodes 28 and 30 are connected to the first and second input / output terminals 32 and 34 of the antenna unit 20, respectively. As a result, balanced input (output) and unbalanced input (output) can be appropriately selected and performed in connection with the antenna unit 20, and the balanced input / output type antenna can be used without using extra circuit components such as a balun. A connection with the unit 20 can be made.

This contributes to the downsizing and high performance of the antenna device 20D, and thus the downsizing and high performance of electronic devices (including communication devices) having the antenna can be reliably realized. .

Also, in the present embodiment, the first to the first
Since the fourth coupling adjustment electrodes 50, 52, 80, and 82 are provided, a filter having a desired bandwidth can be obtained.

Of course, like the antenna device 10Da according to the modification shown in FIG. 20, the fifth dielectric layer S5 on which the third and fourth coupling adjustment electrodes 80 and 82 are formed may be removed. Good.

The antenna device according to the present invention is not limited to the above-described embodiment, but may, of course, adopt various configurations without departing from the gist of the present invention.

[0123]

As described above, according to the antenna device of the present invention, it is possible to appropriately select balanced input (output) and unbalanced input (output) in connection between the filter unit and the antenna unit. Thus, miniaturization and high performance of electronic devices (including communication devices) having an antenna can be realized.

[Brief description of the drawings]

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

FIG. 2 is a cross-sectional view illustrating a configuration of the antenna device according to the first embodiment when cut in a direction orthogonal to a surface on which an inner-layer ground electrode is formed;

FIG. 3 is a cross-sectional view illustrating a configuration of the antenna device according to the first embodiment when cut in a direction orthogonal to a formation surface of first and second input / output terminals.

FIG. 4 is an explanatory diagram showing patterns of electrodes formed on sixth and seventh dielectric layers in the antenna device according to the first embodiment.

FIG. 5 is an exploded perspective view showing a configuration of a first modified example of the antenna device according to the first embodiment.

FIG. 6 is an exploded perspective view showing a configuration of a second modification of the antenna device according to the first embodiment.

FIG. 7 is an exploded perspective view showing a configuration of a third modification of the antenna device according to the first embodiment.

FIG. 8 is an exploded perspective view illustrating a configuration of an antenna device according to a second embodiment.

FIG. 9 is a perspective view illustrating an appearance of an antenna device according to a second embodiment.

FIG. 10 illustrates a first example of the antenna device according to the second embodiment.
It is a disassembled perspective view which shows the structure of the modification of FIG.

FIG. 11 shows a first example of the antenna device according to the second embodiment.
It is a perspective view which shows the external appearance of the modification of FIG.

FIG. 12 shows a second example of the antenna device according to the second embodiment.
It is a disassembled perspective view which shows the structure of the modification of FIG.

FIG. 13 illustrates a third example of the antenna device according to the second embodiment.
It is a disassembled perspective view which shows the structure of the modification of FIG.

FIG. 14 illustrates a fourth example of the antenna device according to the second embodiment.
It is a perspective view which shows the external appearance of the modification of FIG.

FIG. 15 is a plan view showing a dipole antenna including a first meandering pattern and a second meandering pattern.

FIG. 16 is a plan view showing a loop antenna including a first meandering pattern and a second meandering pattern.

FIG. 17 is an exploded perspective view illustrating a configuration of an antenna device according to a third embodiment.

FIG. 18 is an exploded perspective view showing a configuration of a modified example of the antenna device according to the third embodiment.

FIG. 19 is an exploded perspective view illustrating a configuration of an antenna device according to a fourth embodiment.

FIG. 20 is an exploded perspective view showing a configuration of a modified example of the antenna device according to the fourth embodiment.

[Explanation of symbols]

10A, 10Aa to 10Ac, 10B, 10Ba to 10
Bd, 10C, 10Ca, 10D, 10Da: Antenna device 12: Dielectric substrate 14a, 14b: First and second resonance elements 16: Filter unit 20: Antenna unit 22: Input / output terminal 24: Ground electrode 26: Input / output Electrodes 28, 30 first and second input / output electrodes 32, 34 first and second input / output terminals 36, 38 through holes 40, 42 inner ground electrodes 44a to 44h inner ground electrodes 50 , 52, 80,
82 coupling adjustment electrodes S1 to S14 first to fourteenth dielectric layers

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Takami Hirai 2-56 Sudacho, Mizuho-ku, Nagoya City, Aichi Prefecture Inside Nihon Insulators Co., Ltd. (72) Inventor Yasuhiko Mizutani 2nd Sudacho, Mizuho-ku, Nagoya City, Aichi Prefecture No. 56 Inside Japan Insulators Co., Ltd.

Claims (12)

[Claims] An antenna device comprising: a balanced input / output type antenna unit; and a filter unit in which at least an input / output part connected to the antenna unit is a balanced input / output type. 2. The antenna device according to claim 1, wherein the antenna unit and the filter unit are integrated. 3. The antenna device according to claim 2, further comprising: a dielectric substrate formed by laminating a plurality of dielectric layers, and having at least an input / output terminal and a ground electrode formed on an outer peripheral surface thereof. The filter section is configured by arranging a plurality of open-ended half-wavelength resonators in parallel in the dielectric substrate, and the antenna section is formed on the dielectric substrate. Antenna device. 4. The antenna device according to claim 3, wherein the antenna portion and the filter portion are formed on the dielectric substrate in regions separated from each other in a plane. 5. The antenna device according to claim 3, wherein, of the plurality of half-wave resonators, a position symmetrical with respect to a longitudinal center of the half-wave resonator on the antenna unit side. Wherein the two input / output electrodes are disposed in a dielectric substrate, and the two input / output electrodes are respectively connected to balanced input / output terminals of the antenna unit. 6. The antenna device according to claim 5, wherein said two input / output electrodes are １ ／ of said antenna unit side.
An antenna device, which is capacitively coupled to a wavelength resonator. 7. The antenna device according to claim 5, wherein the two input / output electrodes are １ ／ of the antenna unit side.
An antenna device directly connected to a wavelength resonator. 8. The antenna device according to claim 3, wherein the filter section is provided with a dielectric layer interposed between adjacent half-wavelength resonators in the dielectric substrate. An antenna device comprising: a coupling adjustment electrode that overlaps and capacitively couples these adjacent half-wavelength resonators. 9. The antenna device according to claim 8, wherein a plurality of said coupling adjustment electrodes are formed, and said plurality of coupling adjustment electrodes are line-symmetric with respect to a longitudinal center of said half-wavelength resonator. An antenna device characterized by being formed. 10. The antenna device according to claim 3, wherein the filter section is disposed so as to overlap with both open ends of each of the half-wavelength resonators with a dielectric layer interposed therebetween. An antenna device comprising: a grounded inner layer ground electrode. 11. The antenna device according to claim 3, wherein, of said dielectric substrate, a dielectric constant of a dielectric layer on which an antenna section is formed and a dielectric layer on which a filter section is formed. An antenna device, wherein a dielectric constant of a layer is different. 12. The antenna device according to claim 11, wherein a dielectric constant of the dielectric layer on which the antenna section is formed is lower than a dielectric constant of the dielectric layer on which the filter section is formed. .