JP3949296B2 - Antenna device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a balanced input type antenna apparatus such as a dipole antenna or a loop antenna.
[0002]
[Prior art]
In general, 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.
[0003]
The balanced input type antenna device has a structure in which the antenna device itself is excited without using the ground plate, and the unbalanced input type antenna device has a structure in which the ground plate is used for excitation.
[0004]
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 an inconvenience 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 influence of the casing, and has the advantage that less adjustment work is required than the unbalanced input type antenna device. Further, in terms of performance, the antenna device itself is larger than the unbalanced input type antenna device that excites on the same principle, which is advantageous in terms of gain and bandwidth.
[0006]
Furthermore, conventionally, in order to reduce the size of the antenna device and the size of the communication device, for example, many proposals have been made in which an antenna pattern made of an electrode film is formed on the surface of a dielectric substrate (for example, Japanese Patent Laid-Open No. 10-41722). No., JP-A-9-162633, JP-A-10-32413).
[0007]
[Problems to be solved by the invention]
Conventionally, an unbalanced input type antenna device has been used as a high frequency band antenna device.
[0008]
The reason is that the first-stage filter connected to the antenna device is an unbalanced output method, and therefore when a balanced input type antenna device is connected to this unbalanced output method filter, a balanced-unbalanced converter is used. There was a need to use a balun.
[0009]
When the balun is provided, the number of components is increased and the area occupied by the board is increased, and there is a problem that the antenna device, which is a basic requirement, cannot be reduced in size.
[0010]
That is, at present, it is more advantageous in terms of insertion loss and cost to use an unbalanced input type antenna device.
[0011]
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 downsized, It is clear that high performance can be promoted.
[0012]
Note that the antenna devices according to the various proposed examples in which the antenna pattern is formed on the dielectric substrate are exclusively related to the antenna formation pattern, and no problem is raised regarding the connection of the filter.
[0013]
The present invention has been made in consideration of such problems, and the object of the present invention is to select a balanced input (output) and an unbalanced input (output) as appropriate in connection between the filter and the antenna. It is an object of the present invention to provide an antenna device that can realize downsizing and high performance of an electronic device (including a communication device) having an antenna.
[0014]
[Means for Solving the Problems]
The antenna device according to the present invention includes a balanced input / output antenna unit and a filter unit in which at least an input / output portion connected to the antenna unit is a balanced input / output method.
[0015]
That is, since the input / output method on the antenna unit side in the filter unit is a balanced input / output method, the antenna unit connected to the input / output terminal of the filter unit can be a balanced input type antenna device.
[0016]
As described above, in the antenna device according to the present invention, the balanced input (output) and the unbalanced input (output) can be appropriately selected in connection between the filter unit and the antenna unit, and the electronic apparatus having the antenna unit It is possible to reliably realize downsizing and high performance (including communication equipment).
[0017]
And in the said structure, you may make it comprise the said antenna part and a filter part integrally. In this case, since the antenna portion and the filter portion can be integrated without providing a balun or the like, the antenna device can be further reduced in size.
[0018]
Further, in the above configuration, a dielectric substrate is formed by laminating a number of dielectric layers, and at least an input / output terminal and a ground electrode are formed on an outer peripheral surface thereof, and the filter unit is provided with the dielectric substrate. A plurality of open-ended half-wavelength resonant elements may be arranged in parallel, and the antenna portion may be formed on the dielectric substrate.
[0019]
In this case, the antenna portion may be formed on the surface of the dielectric substrate, or may be formed inside the dielectric substrate. Further, the antenna unit and the filter unit may be formed in a region separated from each other on the dielectric substrate in a plane.
[0020]
Since the half-wavelength resonator used in the filter unit, which is one of the components of the antenna device according to the present invention, is open at both ends, the resonator reaches the end of the dielectric substrate. Therefore, the resonance frequency does not vary due to variations in the substrate dimensions due to the manufacturing process. Therefore, a high-performance antenna device can be provided.
[0021]
Further, in the above configuration, two input / output electrodes arranged in line-symmetric positions with respect to the longitudinal center of at least the output-side half-wave resonator among the plurality of half-wave resonators In the dielectric substrate, and the two input / output electrodes may be connected to the balanced input / output terminals of the antenna unit, respectively.
[0022]
That is, since the filter unit can be selected by appropriately selecting a balanced input (output) and a non-balanced input (output) in connection with the antenna unit, a balanced input / output antenna can be used as the antenna unit. .
[0023]
As described above, the filter unit, which is one of the components of the antenna device according to the present invention, obtains an output from two electrodes symmetrically with respect to the midpoint of the half-wave resonator, thereby obtaining a balanced output. On the contrary, when a signal having an antiphase is input at a symmetrical position to the midpoint of the half-wavelength resonator, resonance can be performed, and thus balanced input is possible.
[0024]
Conventionally, in order to connect a filter and a balanced input / output antenna element, it has been necessary to add a balun between them. However, in the present invention, a balanced input (output) and an unbalanced input are connected to the antenna element. Since (output) can be selected as appropriate, connection with a balanced input / output 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.
[0025]
In the above configuration, the two input / output electrodes may be capacitively coupled to the antenna unit side ½ wavelength resonator, respectively, or the antenna unit side ½ wavelength resonator You may make it connect each directly.
[0026]
Further, in the above configuration, the filter unit is overlapped with the adjacent half-wave resonator in the dielectric substrate with the dielectric layer interposed therebetween, and the adjacent half-wave resonator is capacitively coupled. A coupling adjusting electrode may be provided.
[0027]
As a result, capacitances are formed between the coupling adjustment electrode and the half-wave resonator and between the coupling adjustment electrode and another half-wave resonator, respectively. In terms of an equivalent circuit, the combined capacitance of these capacitors is connected in parallel with the inductive coupling formed between the adjacent half-wave resonators, so that the inductive coupling degree is adjusted by the capacitance. And a filter having a desired bandwidth can be obtained.
[0028]
The capacitance can be easily adjusted by changing the overlapping area of the half-wave resonator and the coupling adjustment electrode, the distance between them, and / or the relative dielectric constant εr of the dielectric between them. it can.
[0029]
In addition, since the combined capacitance by the coupling adjusting electrode is connected in parallel with the inductive coupling between the half-wave resonators, a parallel resonant circuit is inserted and connected between the adjacent half-wave resonators. That's right. Since the impedance of the parallel resonance circuit composed of this capacitance and inductance changes from inductive to capacitive before and after the parallel resonance point, the capacitance of the capacitance formed between the adjacent 1/2 wavelength resonator and the coupling adjustment electrode respectively. By adjusting the value, the coupling between the half-wave resonators can be made inductive or capacitive.
[0030]
Considering the case where the coupling between the half-wave resonators is inductive, a parallel resonance point exists on the high frequency side of the passband, so that a filter having an attenuation pole on the high frequency side is obtained. If the coupling between the half-wave resonators is made capacitive, a parallel resonance point exists on the low frequency side of the passband, and a filter having an attenuation pole on the low frequency side is obtained. The attenuation characteristic of the filter can be improved.
[0031]
Further, in the above configuration, a plurality of the coupling adjustment electrodes may be formed, and the plurality of coupling adjustment electrodes may be formed in a line-symmetric position with respect to the longitudinal center of the ½ wavelength resonator.
[0032]
In this case, it is possible to suppress the influence of the positional deviation between the ½ wavelength resonator and the junction adjustment electrode in the manufacturing process. Specifically, the effect of the coupling adjustment electrode is affected by the relative position to the half-wave resonator, but the coupling adjustment electrode is placed in a line-symmetrical position with respect to the longitudinal center of the half-wave resonator. By forming, even if a positional shift occurs in the longitudinal direction of the half-wave resonator, the change in the effect of the plurality of coupling adjustment electrodes cancels each other, and the half-wave resonator and the junction adjustment are performed. The influence of the positional deviation from the electrode can be suppressed.
[0033]
Further, in the above configuration, the filter portion may be provided with an inner layer ground electrode disposed so as to overlap with both open ends of the ½ wavelength resonators with a dielectric layer interposed therebetween.
[0034]
In this case, the capacitance formed between the open end side of each 1/2 wavelength resonator and the inner layer ground electrode is also added to the capacitance of the parallel resonance circuit when equivalently converting the 1/2 wavelength resonator. Therefore, if the resonance frequency is the same, the inductance of the parallel resonance circuit can be reduced, and as a result, the length of the 1/2 wavelength resonator (resonator length) must be further reduced. Thus, the entire length of the filter unit can be shortened.
[0035]
In this case, in order to reduce the size of the filter unit, if the facing area between the inner-layer ground electrode and each 1/2 wavelength resonator is increased, the 1/2 wavelength resonators are inductively coupled to each other more and more. However, in the present invention, since the above-described coupling adjustment electrode is provided, a capacitance formed between the coupling adjustment electrode and the ½ wavelength resonator is generated. As a result, the absolute value of the total susceptance composed of the capacitance between the ½ wavelength resonators and the inductive coupling between the ½ wavelength resonators changes. Therefore, the degree of coupling between the half-wave resonators can be adjusted by adjusting the value of the capacitance, and a filter having a desired bandwidth can be obtained.
[0036]
In addition, even if stacking deviation occurs in the longitudinal direction (axial direction) of the 1/2 wavelength resonator between the 1/2 wavelength resonator and the inner layer ground electrode, the capacitance change of each open end of the 1/2 wavelength resonator is changed. Since they cancel each other, variations in resonance frequency can be reduced.
[0037]
In the above configuration, the dielectric constant of the dielectric layer in which the antenna portion is formed in the dielectric substrate may be different from the dielectric constant of the dielectric layer in which the filter portion is formed. In particular, by making the dielectric constant of the dielectric layer on which the antenna portion is formed lower than the dielectric constant of the dielectric layer on which the filter portion is formed, the filter portion can be reduced in size, and at the same time, the bandwidth of the antenna portion can be reduced. Reduction and reduction in gain can be effectively suppressed.
[0038]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, several embodiments of an antenna device according to the present invention will be described with reference to FIGS. For convenience of explanation, in the drawings, the left side of the antenna element shown in these drawings is referred to as the left side, the right side as the right side, the near side as the front, and the depth side as the back. .
[0039]
As shown in FIG. 1, the antenna device 10A according to the first embodiment has two ends open in a dielectric substrate 12 formed by laminating and firing a plurality of plate-like dielectric layers. A half-wavelength resonant element 14a and 14b is formed in parallel with each other, and an antenna unit 20 including a dipole antenna 18 formed of an electrode film on the upper surface of the dielectric substrate 12 is provided. Configured.
[0040]
Specifically, as shown in FIG. 1, the dielectric substrate 12 is configured by stacking a first dielectric layer S1 to a ninth dielectric layer S9 in order from the top. These first to ninth dielectric layers S1 to S9 are composed of one or a plurality of layers.
[0041]
The antenna unit 20 and the filter unit 16 are formed on the dielectric substrate 12 in a region separated from each other in a plane. For example, in FIG. 1, the filter unit 16 is formed in the left region, and the antenna unit 20 is formed in the right region. Further, the antenna unit 20 is formed on the upper surface of the first dielectric layer S1, and the filter unit 16 is formed from the second dielectric layer S2 to the ninth dielectric layer S9.
[0042]
As shown in FIG. 3, one input / output terminal 22 is formed on the left side of the outer peripheral surface of the dielectric substrate 12, for example, and the ground electrode 24 extends from the left side to the lower side excluding the input / output terminal 22. Is formed.
[0043]
In the filter unit 16 of the antenna device 10A according to the first embodiment, as shown in FIG. 1, two resonant elements 14a and 14b (first elements) are formed on one main surface of the sixth dielectric layer S6. The first and second resonant elements 14a and 14b) are formed in parallel, respectively. These resonators 14a and 14b are open at both ends.
[0044]
One main surface of the fifth dielectric layer S5 located above the sixth dielectric layer S6 is provided with one input / output electrode 26 and two input / output electrodes (first and second input electrodes). Output electrodes 28 and 30) are formed.
[0045]
One end of the input / output electrode 26 is connected to the input / output terminal 22 (see FIG. 2) and is capacitively coupled to the first resonant element 14a. The first and second input / output electrodes 28 and 30 each have one end connected to two balanced input / output terminals (first and second input / output terminals 32 and 34) of the dipole antenna 18 through through holes 36 and 38, respectively. It is formed so as to be connected and capacitively coupled to the second resonance element 14b.
[0046]
That is, the filter unit 16 is directly connected to the antenna unit 20 by a balanced input / output method without using an additional circuit component such as a balun. Further, the other input / output electrode 26 is connected to another circuit (not shown) in a non-balanced input / output system.
[0047]
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) each have a rectangular shape extending from the left side surface of the dielectric substrate 12. Inner layer ground electrodes 40 and 42 having a relatively large area are formed.
[0048]
On one main surface of the fourth dielectric layer S4 and one main surface of the eighth dielectric layer S8, there are four inner layer ground electrodes corresponding to both ends of the two resonance elements 14a and 14b, that is, A total of eight inner layer ground electrodes (first to eighth inner layer ground electrodes) 44a to 44h are formed.
[0049]
In this case, the first, third, fifth and seventh inner-layer ground electrodes 44a, 44c, 44e and 44g are formed so as to face one open end of each of the first and second resonance elements 14a and 14b. The second, fourth, sixth, and eighth inner-layer ground electrodes 44b, 44d, 44f, and 44h are formed to face the other open ends of the first and second resonance elements 14a and 14b. ing.
[0050]
Further, the first to fourth inner layer ground electrodes 44a to 44d are electrically connected to the inner layer ground electrode 40 formed on one main surface of the second dielectric layer S2 through through holes 46a to 46d, respectively. The fifth to eighth inner layer ground electrodes 44e to 44h are electrically connected to the inner layer ground electrode 42 formed on the other main surface of the ninth dielectric layer S9 through the through holes 46e to 46h, respectively. Yes.
[0051]
On one main surface of the seventh dielectric layer S7, there are two coupling adjustment electrodes (first and second couplings) which are in a floating state with respect to the ground electrode 24, the input / output terminal 22 and the antenna unit 20. Adjustment electrodes 50 and 52) are formed.
[0052]
The first and second coupling adjusting electrodes 50 and 52 are strip-shaped second electrode bodies 50a and 52a facing the first resonance element 14a and strip-shaped second electrodes facing the second resonance element 14b. The electrode bodies 50b and 52b are electrically connected by lead electrodes 50c and 52c formed therebetween.
[0053]
Furthermore, in this embodiment, the first and second coupling adjustment electrodes 50 and 52 are line-symmetric with respect to the center line m in the longitudinal direction of the two resonance elements 14a and 14b, as shown in FIG. It is formed at the position.
[0054]
The antenna device 10A according to the first embodiment is basically configured as described above. Here, the electrical coupling of each electrode will be described with reference to FIGS. To do.
[0055]
First, as shown in FIG. 2, there are electrostatic charges 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, respectively. Capacitors C1 and C2 and C3 and C4 are formed. Between both open ends of the second resonant element 14b and the third, fourth, seventh and eighth inner layer ground electrodes 44c, 44d, 44g and 44h. Capacitances C5 and C6 and C7 and C8 are formed, respectively.
[0056]
Adjacent resonant elements 14a and 14b are inductively coupled to each other, whereby an inductance L is inserted between adjacent resonant elements 14a and 14b on the equivalent circuit.
[0057]
Further, 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, the first input / output electrode 28, And capacitances C10 and C11 are formed between the second resonance element 14b and the second input / output electrode 30, respectively.
[0058]
Further, capacitances C12 and C13 are formed 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, respectively. Capacitances C14 and C15 are formed between the first resonance element 14a and the second coupling adjustment electrode 52, and between the second coupling adjustment electrode 52 and the second resonance element 14b, respectively. Yes.
[0059]
As described above, in the antenna device 10A according to the first embodiment, a dielectric body in which a large number of dielectric layers are laminated and at least the input / output terminal 22 and the ground electrode 24 are formed on the outer peripheral surface thereof. A substrate 12 is provided, the filter unit 16 is configured by arranging the first and second resonant elements 14 a and 14 b in parallel in the dielectric substrate 12, and the antenna unit 20 is formed on the upper surface of the dielectric substrate 12. To be formed.
[0060]
Since the first and second resonant elements 14 a and 14 b used in the filter unit 16 are open at both ends, the first and second resonant elements 14 a reach the end of the dielectric substrate 12. 14b does not need to be extended, 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.
[0061]
In addition, among the first and second resonance elements 14a and 14b, at least two input / output electrodes 28 and 30 arranged in line-symmetrical positions with respect to the longitudinal center of the second resonance element 14b are dielectrically connected. Since the first and second input / output electrodes 28 and 30 are provided in the body substrate 12 and are connected to the first and second input / output terminals 32 and 34 of the antenna unit 20, respectively, In this connection, balanced input (output) and unbalanced input (output) can be selected as appropriate, and a balanced input / output antenna (for example, dipole antenna 18) can be used as the antenna unit 20.
[0062]
As described above, the filter unit 16 can obtain a balanced output by obtaining outputs from the two electrodes at positions symmetrical with respect to the midpoints of the first and second resonant elements 14a and 14b. In addition, when a signal having an opposite phase is input at a position symmetric with respect to the midpoint of the first and second resonance elements 14a and 14b, resonance can be achieved, thereby enabling balanced input.
[0063]
Conventionally, in order to connect a filter and a balanced input / output type antenna element, it has been necessary to add a balun between them. In this embodiment, a balanced input (output) is connected to the antenna unit 20. Since the unbalanced input (output) can be appropriately selected and performed, the connection with the balanced input / output antenna unit 20 can be performed without using an extra circuit component such as a balun. This contributes to miniaturization and high performance of the antenna device 10A, and as a result, downsizing and high performance of electronic devices (including communication devices) having an antenna can be reliably realized.
[0064]
In this embodiment, the filter unit 16 overlaps the first and second resonance elements 14a and 14b adjacent in the dielectric substrate 12 with the sixth dielectric layer S6 interposed therebetween, and Since the first and second coupling adjustment electrodes 50 and 52 for capacitively coupling the adjacent first and second resonant elements 14a and 14b are provided, the first and second coupling adjustment electrodes 50 and 52, Capacitances are formed between the first resonance element 14a and between the first and second coupling adjustment electrodes 50 and 52 and the second resonance element 14b, respectively. In terms of an equivalent circuit, the combined capacitance of these capacitors is connected in parallel with the inductance L formed between the adjacent first and second resonant elements 14a and 14b. And a filter having a desired bandwidth can be obtained.
[0065]
The capacitance adjustment is performed by adjusting the overlapping area of the first and second resonant elements 14a and 14b and the first and second coupling adjustment electrodes 50 and 52 and the distance between them and / or the dielectric between them. This can be done easily by changing the relative dielectric constant εr.
[0066]
Since the combined capacitance of the first and second coupling adjustment electrodes 50 and 52 is connected in parallel with the inductance L between the first and second resonant elements 14a and 14b, the adjacent first and second A parallel resonant circuit is inserted and connected between the second resonant elements 14a and 14b. Since the impedance of the parallel resonance circuit composed of this capacitance and inductance changes from inductive to capacitive before and after the parallel resonance point, the adjacent first and second resonant elements 14a and 14b and the first and second By adjusting the value of the capacitance formed between the coupling adjustment electrodes 50 and 52, the coupling between the first and second resonant elements 14a and 14b can be made inductive or capacitive.
[0067]
Considering the case where the coupling between the first and second resonance elements 14a and 14b is inductive, a parallel resonance point exists on the high frequency side of the pass band, and therefore a filter having an attenuation pole on the high frequency side is provided. If the coupling between the first and second resonant elements 14a and 14b is made capacitive, a parallel resonance point exists on the low frequency side of the passband, and an attenuation pole is provided on the low frequency side. In any case, the attenuation characteristics of the filter can be improved.
[0068]
Furthermore, in this embodiment, the first and second coupling adjustment electrodes 50 and 52 are formed at positions symmetrical with respect to the longitudinal center of the first and second resonance elements 14a and 14b. Therefore, it is possible to suppress the influence of the positional deviation between the first and second resonant elements 14a and 14b and the first and second junction adjustment electrodes 50 and 52 in the manufacturing process. Specifically, the effects of the first and second coupling adjustment electrodes 50 and 52 are affected by the relative positions of the first and second resonance elements 14a and 14b. 50 and 52 are formed at positions symmetrical with respect to the longitudinal center of the first and second resonant elements 14a and 14b, so that they are positioned in the longitudinal direction of the first and second resonant elements 14a and 14b. Even if a deviation occurs, the change in the effects of the first and second coupling adjustment electrodes 50 and 52 cancel each other, and the first and second resonant elements 14a and 14b and the first and second junctions are offset. The influence of the positional deviation with respect to the adjustment electrodes 50 and 52 can be suppressed.
[0069]
Further, in the present embodiment, since the inner layer ground electrodes 44a to 44h arranged so as to overlap each other with the dielectric layer sandwiched between the open ends of the first and second resonance elements 14a and 14b, The capacitance formed between the open end sides of the first and second resonant elements 14a and 14b and the inner layer ground electrodes 44a to 44h is also equivalent to when the first and second resonant elements 14a and 14b are equivalently converted. Since it is added to the capacitance of the parallel resonance circuit, if the resonance frequency is the same, the inductance of the parallel resonance circuit can be reduced. As a result, the first and second resonance elements 14a and 14 The length of 14b (resonator length) can also be reduced, and the overall length of the filter unit 16 can be shortened.
[0070]
In this case, in order to reduce the size of the filter section 16, if the opposing area between the inner ground electrodes 44a to 44h and the first and second resonance elements 14a and 14b is increased, the first and second resonances are increased. The elements 14a and 14b are inductively coupled to each other, which causes a problem that the characteristics of the filter are too broad.
[0071]
However, in the present embodiment, since the first and second coupling adjustment electrodes 50 and 52 described above are provided, the first and second coupling adjustment electrodes 50 and 52 and the first and second coupling adjustment electrodes 50 and 52 are provided. The capacitance formed between the first and second resonance elements 14a and 14b includes an electrostatic capacitance between the first and second resonance elements 14a and 14b and an inductive coupling between the first and second resonance elements 14a and 14b. The absolute value of the total susceptance will change. Therefore, by adjusting this capacitance value, the degree of coupling between the first resonant element 14a and the second resonant element 14b can be adjusted, and a filter having a desired bandwidth can be obtained.
[0072]
Even if the first and second resonance elements 14a and 14b and the inner ground electrodes 44a to 44h cause a stacking deviation in the longitudinal direction (axial direction) of the first and second resonance elements 14a and 14b, Since the capacitance changes at the open ends of the first and second resonance elements 14a and 14b cancel each other, variations in the resonance frequency can be reduced.
[0073]
Next, some modified examples of the antenna device 10A according to the first embodiment will be described with reference to FIGS. In addition, the same code | symbol is attached | subjected about the thing corresponding to FIG. 1, and the duplication description is abbreviate | omitted.
[0074]
First, the antenna device 10Aa according to the first modification has substantially the same configuration as the antenna device 10A according to the first embodiment (see FIG. 1) as shown in FIG. The difference is that two input / output electrodes (first and second input / output electrodes 26a and 26b) are formed on one main surface of the layer S5.
[0075]
In this case, the filter unit 16 is connected to the antenna unit 20 in a balanced input / output manner through the first and second input / output electrodes 28 and 30 on the antenna unit 20 side, and the first and second input / outputs on the opposite side. The other electrodes (not shown) are connected through the electrodes 26a and 26b for balanced input / output.
[0076]
In the antenna device 10A according to the first embodiment described above, the connection end of the filter unit 16 with another circuit is an unbalanced input / output system, and the antenna device 10Aa according to the first modification includes the filter unit The connection end with the other circuit in 16 is a balanced input / output system. The various embodiments and various modifications related to the present invention are the same regardless of whether the connection end of the filter unit 16 with another circuit is a balanced input / output system or an unbalanced input / output system. Therefore, in the following modifications and description of the embodiments, an example in which the connection end with another circuit is an unbalanced input / output method is shown, and the description of the balanced input / output method is omitted.
[0077]
Next, as shown in FIG. 6, the antenna device 10Ab according to the second modification has substantially the same configuration as the antenna device 10A according to the first embodiment (see FIG. 1). The difference is that a tenth dielectric layer S10 is further stacked on one main surface side of the body layer S1.
[0078]
That is, in the antenna device 10A according to the first embodiment described above, the antenna unit 20 is exposed from the dielectric substrate 12. However, in the antenna device 10Ab according to the second modified example, the antenna unit 20 includes the antenna unit 20A. The dielectric substrate 12 has a built-in form.
[0079]
Here, the difference between the case where the antenna unit 20 is formed on the surface of the dielectric substrate 12 and the case where it is formed inside the dielectric substrate 12 will be described.
[0080]
When the antenna unit 20 is formed on the surface of the dielectric substrate 12, the effective dielectric constant is lower than when it is formed inside the dielectric substrate 12. The reason is that when the antenna portion 20 is formed on the surface of the dielectric substrate 12, the radiation conductor is also facing air (dielectric constant = 1), so that the effective dielectric constant is affected by air. Therefore, the antenna unit 20 can be downsized if the antenna unit 20 is formed inside the dielectric substrate 12.
[0081]
However, in general, when the dielectric substrate 12 is made of a material having a high dielectric constant, problems such as a decrease in the bandwidth of the antenna unit 20 and a decrease in gain occur. Therefore, the dielectric used is used while balancing the shape and the required characteristics. The dielectric constant of the body or the formation position of the antenna to be used is determined.
[0082]
Next, as shown in FIG. 7, the antenna device 10Ac according to the third modification has substantially the same configuration as the antenna device 10A according to the first embodiment (see FIG. 1). The difference is that the antenna unit 20 is formed on one main surface of the third dielectric layer S3 without forming the antenna unit 20 on one main surface of the body layer S1.
[0083]
That is, the antenna device 10A according to the first embodiment described above has a configuration in which the antenna unit 20 is positioned above the filter unit 16, but the antenna device 10Ac according to the third modification example has an antenna. The part 20 has a form formed at substantially the same position as the filter part 16. This is based on the fact that the antenna unit 20 does not necessarily have to be above the filter unit 16.
[0084]
Next, an antenna device 10B according to a second embodiment will be described with reference to FIGS. In addition, the same code | symbol is attached | subjected about the thing corresponding to FIG. 1, and the duplication description is abbreviate | omitted.
[0085]
The antenna device 10B according to the second embodiment has substantially the same configuration as the antenna device 10A according to the first embodiment (see FIG. 1), as shown in FIG. The antenna unit 20 formed on one main surface of the layer S1 is a loop antenna 60, and the interior ground electrode 44a formed on each main surface of the fourth dielectric layer S4 and the eighth dielectric layer S8. To 44h are directly connected to the ground electrode 24 formed on the front surface and the back surface of the dielectric substrate 12, as shown in FIG. 9, and one main surface of the second dielectric layer S2 and the ninth The interior ground electrodes 40 and 42 formed on the other main surface of the dielectric layer S9 are different in that they are formed so as to extend to the front surface and the back surface of the dielectric substrate 12.
[0086]
Also in the antenna device 10B according to the second embodiment, the first and second resonance elements 14a and 14b used in the filter unit 16 are provided in the same manner as the antenna device 10A according to the first embodiment. Because both ends are open, it is not necessary to extend the resonator to the end of the dielectric substrate 12, and the resonance frequency varies due to variations in the substrate dimensions due to the manufacturing process. There is nothing. Therefore, a high-performance antenna device 10B can be provided.
[0087]
Further, of the first and second resonance elements 14a and 14b, at least first and second input / output electrodes 28 arranged at line-symmetrical positions with respect to the longitudinal center of the second resonance element 14b. And 30 are provided in the dielectric substrate 12, and 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. In connection with the antenna unit 20, balanced input (output) and unbalanced input (output) can be selected as appropriate, and the balanced input / output type antenna unit 20 can be used without using extra circuit components such as a balun. Can be connected.
[0088]
This contributes to miniaturization and high performance of the antenna device 10B, and as a result, downsizing and high performance of electronic devices (including communication devices) having an antenna can be reliably realized.
[0089]
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.
[0090]
Next, several modifications of the antenna device 10B according to the second embodiment will be described with reference to FIGS. In addition, about the thing corresponding to FIG. 8, the same code | symbol is attached | subjected and the duplication description is abbreviate | omitted.
[0091]
First, as shown in FIG. 10, the antenna device 10Ba according to the first modification has substantially the same configuration as the antenna device 10B according to the second embodiment (see FIG. 8). FIG. 11 shows a first meander pattern 60a made of an electrode film formed on one main surface of the layer S1, a second meander pattern 60b made of an electrode film formed on one main surface of the ninth dielectric layer S9, As shown, a loop antenna is formed by a conductor pattern 60c formed on the right side surface of the dielectric substrate 12 and electrically connecting one end of the first serpentine pattern 60a and one end of the second serpentine pattern 60b. 60 (antenna unit 20) is different.
[0092]
In this case, the other end portion (first input / output terminal 32) of the first meandering pattern 60a and the first input / output electrode 28 are electrically connected through the through hole 36, and the second meandering pattern 60b. The other end (second input / output terminal 34) and the second input / output electrode 30 are electrically connected through a through hole 38.
[0093]
In the first modification, the meandering patterns 60a and 60b are included in the loop antenna 60 (antenna unit 20), so that the effective antenna length can be increased, and the antenna unit 20 can be downsized accordingly. Can be made.
[0094]
Next, as shown in FIG. 12, the antenna device 10Bb according to the second modification has substantially the same configuration as the antenna device 10B according to the second embodiment (see FIG. 8), but the first dielectric The difference is that a tenth dielectric layer S10 is further stacked on one main surface side of the body layer S1.
[0095]
That is, in the antenna device 10B according to the second embodiment described above, the antenna unit 20 is exposed from the dielectric substrate 12. However, in the antenna device 10Bb according to the second modified example, the antenna unit 20 includes the antenna unit 20B. The dielectric substrate 12 has a built-in form.
[0096]
In this case, since the effective dielectric constant of the antenna unit 20 is higher than when the antenna unit 20 is formed on the surface of the dielectric substrate 12, the antenna unit 20 can be downsized.
[0097]
Next, as shown in FIG. 13, the antenna device 10Bc according to the third modification has substantially the same configuration as the antenna device 10Ba according to the first modification (see FIG. 10). A tenth dielectric layer S10 is further laminated on one principal surface side of the layer S1, and an eleventh dielectric layer S11 is laminated on the other principal surface side of the ninth dielectric layer S9; One difference is that one end portion of one meandering pattern 60 a and one end portion of the second meandering pattern 60 b are electrically connected through a through hole 62 inside the dielectric substrate 12.
[0098]
That is, in the antenna device 10Ba according to the first modification described above, the antenna unit 20 is exposed from the dielectric substrate 12. However, in the antenna device 10Bc according to the third modification, the antenna unit 20 is dielectric. It becomes a form that is built in the body substrate 12.
[0099]
In this case, the effective dielectric constant of the antenna unit 20 is higher than when the antenna unit 20 is formed on the surface of the dielectric substrate 12, and the effective antenna length is increased by the meandering patterns 60a and 60b. Can be further reduced in size.
[0100]
Next, as shown in FIG. 14, the antenna device 10 </ b> Bd according to the fourth modified example has substantially the same configuration as the antenna device 10 </ b> B (see FIG. 9) according to the second embodiment. The difference is that the loop antenna 60 to be formed is formed over the top surface, front surface, right side surface and back surface of the dielectric substrate 12.
[0101]
Also in this case, since the effective antenna length can be increased, the size of the antenna unit 20 can be reduced.
[0102]
In the antenna device 20B according to the second embodiment described above and the antenna devices 10Ba to 10Bd according to the first to fourth modifications, an example in which the loop antenna 60 is used as the antenna unit 20 has been shown. As shown in FIG. 15, a dipole antenna 70 composed of a first meandering pattern 60a and a second meandering pattern 60b may be used.
[0103]
In the antenna devices 10Ba and 10Bc according to the first and third modifications, the first meandering pattern 60a and the second meandering pattern 60b are formed on different dielectric layers, respectively. As shown in FIG. 16, it may be formed on the same dielectric layer (for example, one main surface of the first dielectric layer S1).
[0104]
By the way, as one of the methods for reducing the size of an electronic component, it is possible to use a high dielectric constant material.
[0105]
In this case, the filter unit 16 can use a high dielectric constant material with relatively no problem. However, in the antenna unit 20, as the dielectric constant of the material increases, the bandwidth of the antenna decreases and the gain decreases. Problems arise.
[0106]
The antenna device 10C according to the third embodiment described below solves such a problem.
[0107]
An antenna device 10C according to a third embodiment will be described with reference to FIG. In addition, the same code | symbol is attached | subjected about the thing corresponding to FIG. 1, and the duplication description is abbreviate | omitted.
[0108]
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), but the antenna unit 20 is formed. Instead of the first dielectric layer S1, the twelfth dielectric layer S12 having a lower dielectric constant than the first to ninth dielectric layers S1 to S9 is used. The low dielectric constant thirteenth and fourteenth dielectric layers S13 and S14 between the point where the antenna portion 20 is formed on one main surface and the twelfth dielectric layer S12 and the second dielectric layer S2. It differs in that it is laminated. Of course, these twelfth to fourteenth dielectric layers S12 to S14 are each composed of one or a plurality of layers, similarly to the first to eleventh dielectric layers S1 to S11.
[0109]
As described above, in the antenna device 10C according to the third embodiment, the high dielectric constant dielectric layers S2 to S9 can be used for the filter unit 16, and the low dielectric constant dielectric layer S12 for the antenna unit 20. Since S14 can be used, the filter unit 16 can be reduced in size, and at the same time, it is possible to effectively suppress a reduction in bandwidth and a reduction in gain in the antenna unit 20.
[0110]
Next, a modification of the antenna device 10C according to the third embodiment will be described with reference to FIG. Note that components corresponding to those in FIG. 17 are denoted by the same reference numerals, and redundant description thereof is omitted.
[0111]
As shown in FIG. 18, the antenna device 10Ca according to this modification has substantially the same configuration as the antenna device 10C according to the third embodiment (see FIG. 17), but one of the thirteenth dielectric layers S13. The difference is that the antenna portion 20 is formed on the main surface.
[0112]
That is, in the antenna device 10C according to the third embodiment described above, the antenna unit 20 is exposed from the dielectric substrate 12, but in the antenna device 10Ca according to this modification, the antenna unit 20 is the dielectric substrate. 12 is an internal form.
[0113]
In this case, since the effective dielectric constant of the antenna unit 20 is higher than when the antenna unit 20 is formed on the surface of the dielectric substrate 12, the antenna unit 20 can be downsized.
[0114]
Next, an antenna device 10D according to a fourth embodiment will be described with reference to FIG. In addition, about the thing corresponding to FIG. 8, the same code | symbol is attached | subjected and the duplication description is abbreviate | omitted.
[0115]
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). The input / output electrode 26 is directly connected to the first resonance element 14a formed on one main surface of the layer S6, and the first and second input / output electrodes 28 and 30 are directly formed on the second resonance element 14b. And third and second coupling electrodes having the same configuration as the first and second coupling adjustment electrodes 50 and 52 formed in the seventh dielectric layer S7 on one main surface of the fifth dielectric layer S5. The difference is that four coupling adjusting electrodes 80 and 82 are formed.
[0116]
That is, in the antenna device 10D according to the fourth embodiment, the input / output terminal 22 formed on the left side surface of the dielectric substrate 12 and the first resonance element 14a in the dielectric substrate 12 are input / output electrodes. 26, the first and second input / output terminals 32 and 34 of the antenna unit 20 and the second resonance element 14b are respectively connected via the first and second input / output electrodes 28 and 30. Connected directly.
[0117]
Also in the antenna device 10D according to the fourth embodiment, the first and second resonance elements 14a and 14b used in the filter unit 16 are provided in the same manner as the antenna device 10A according to the first embodiment. Since both ends are open, it is not necessary to extend the first and second resonant elements 14a and 14b to the end of the dielectric substrate 12, and the size of the substrate by the manufacturing process can be reduced. The resonance frequency does not vary due to fluctuations or the like. Therefore, a high-performance antenna device 10D can be provided.
[0118]
Further, of the first and second resonance elements 14a and 14b, at least first and second input / output electrodes 28 arranged in line-symmetrical positions with respect to the longitudinal center of the second resonance element 14b. And 30 are provided in the dielectric substrate 12, and 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. In connection with the antenna unit 20, balanced input (output) and unbalanced input (output) can be selected as appropriate, and the balanced input / output type antenna unit 20 can be used without using extra circuit parts such as a balun. Can be connected.
[0119]
This contributes to miniaturization and high performance of the antenna device 20D, and as a result, downsizing and high performance of electronic devices (including communication devices) having an antenna can be reliably realized.
[0120]
Also in this embodiment, since the first to fourth coupling adjustment electrodes 50, 52, 80 and 82 are provided, a filter having a desired bandwidth can be obtained.
[0121]
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.
[0122]
Of course, the antenna device according to the present invention is not limited to the above-described embodiments, and various configurations can be adopted without departing from the gist of the present invention.
[0123]
【The invention's effect】
As described above, according to the antenna device of the present invention, a balanced input (output) and an unbalanced input (output) can be appropriately selected in connection between the filter unit and the antenna unit, and the antenna is provided. Electronic devices (including communication devices) can be reduced in size and performance.
[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 showing a configuration when the antenna device according to the first embodiment is cut in a direction orthogonal to a formation surface of an inner-layer ground electrode.
FIG. 3 is a cross-sectional view showing a configuration when the antenna device according to the first embodiment is cut in a direction orthogonal to the formation surfaces of the first and second input / output terminals.
FIG. 4 is an explanatory diagram showing electrode patterns 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 modification 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 showing 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 is an exploded perspective view showing a configuration of a first modification of the antenna device according to the second embodiment.
FIG. 11 is a perspective view illustrating an appearance of a first modification of the antenna device according to the second embodiment.
FIG. 12 is an exploded perspective view showing a configuration of a second modification of the antenna device according to the second embodiment.
FIG. 13 is an exploded perspective view showing a configuration of a third modification of the antenna device according to the second embodiment.
FIG. 14 is a perspective view showing an appearance of a fourth modification of the antenna device according to the second embodiment.
FIG. 15 is a plan view showing a dipole antenna composed of a first serpentine pattern and a second serpentine pattern.
FIG. 16 is a plan view showing a loop antenna composed of a first meandering pattern and a second meandering pattern.
FIG. 17 is an exploded perspective view showing a configuration of an antenna device according to a third embodiment.
FIG. 18 is an exploded perspective view showing a configuration of a modification of the antenna device according to the third embodiment.
FIG. 19 is an exploded perspective view showing 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-10Ac, 10B, 10Ba-10Bd, 10C, 10Ca, 10D, 10Da ... antenna device
12 ... Dielectric substrate
14a, 14b ... first and second resonant elements
16 ... Filter part 20 ... Antenna part
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 hole 40, 42 ... inner layer ground electrode
44a to 44h ... inner layer ground electrode 50, 52, 80, 82 ... coupling adjustment electrode
S1 to S14 ... 1st to 14th dielectric layers

Claims (8)

In an antenna apparatus having 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, and the antenna unit and the filter unit are integrated ,
Comprising a dielectric substrate in which a large number of dielectric layers are laminated, and at least an input / output terminal and a ground electrode are formed on the outer peripheral surface thereof;
The filter unit is configured by arranging a plurality of open both-end half-wave resonators in parallel in the dielectric substrate,
The antenna portion is formed on the dielectric substrate,
The filter unit has a coupling adjustment electrode that overlaps with the adjacent half-wave resonator in the dielectric substrate with a dielectric layer interposed therebetween, and that capacitively couples the adjacent half-wave resonators. And
The coupling adjusting electrode is formed with a plurality of antenna devices plurality of coupling adjusting electrode is characterized that you have been formed at a position axisymmetric with respect to the longitudinal direction center of the half-wave resonator. The antenna device according to claim 1 , wherein
Before SL filter unit, an antenna apparatus characterized by having an inner layer ground electrodes disposed so as to overlap each other across the dielectric layer at both open ends of the respective half-wave resonator. The antenna device according to claim 1 , wherein
Before Symbol of the dielectric substrate, an antenna apparatus characterized by the dielectric constant of the dielectric constant and the filter portion of the antenna portion is formed dielectric layer was formed a dielectric layer is different. The antenna device according to claim 3 , wherein
An antenna device, wherein a dielectric constant of a dielectric layer in which the antenna portion is formed is lower than a dielectric constant of a dielectric layer in which the filter portion is formed. In the antenna device according to any one of claims 1 to 4 ,
The antenna device, wherein the antenna unit and the filter unit are formed in a region separated from each other in plan on the dielectric substrate. In the antenna device according to any one of claims 1 to 5 ,
Among the plurality of half-wave resonators, two input / output electrodes arranged in line-symmetrical positions with respect to the center in the length direction of the half-wave resonator on the antenna side are provided in the dielectric substrate. Have
The antenna device, wherein the two input / output electrodes are respectively connected to balanced input / output terminals of the antenna unit. The antenna device according to claim 6 , wherein
The antenna device according to claim 2, wherein the two input / output electrodes are capacitively coupled to a half-wave resonator on the antenna unit side. The antenna device according to claim 6 , wherein
The antenna device according to claim 1, wherein the two input / output electrodes are directly connected to a half-wave resonator on the antenna section side.

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