JP2003304102A - Complex resonator and band pass filter using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a complex resonator having a plurality of resonance frequencies capable of arbitrarily setting at least two resonance frequencies of the plurality of resonance frequencies. <P>SOLUTION: This complex resonator is provided with dielectric boards 21-1 to 21-4 and first and second coplaner lines formed on a dielectric board 21-3. In a first frequency, a transmission line A configuring the first coplaner line is made to function as a ground pattern configuring a second coplaner line, and in a second frequency different from the first frequency, a transmission line B configuring the second coplaner line is made to function as a ground pattern configuring the first coplaner line. Thus, the length of the transmission line A configuring the first coplaner line and the length of the transmission line B configuring the second coplaner line is adjusted so that the resonance frequencies of those coplaners can be independently set. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composite resonator and a bandpass filter using the same, and more specifically,
The present invention relates to a composite resonator in which each resonance frequency can be set arbitrarily and a bandpass filter using the same.

[0002]

2. Description of the Related Art Today, there are remarkable miniaturization of information communication terminals typified by mobile phones, and miniaturization of various parts incorporated in the information communication terminals greatly contributes to this. A band pass filter is one of the most important parts incorporated in an information communication terminal.

As a general bandpass filter, a filter formed by combining a plurality of λ / 4 dielectric resonators is known. In such a bandpass filter, not only the frequency based on the resonance of the lowest order mode but also an odd multiple (3 times, 5 times, 7 times) of that based on the resonance of the higher order mode.
Since a pass characteristic is exhibited even at a frequency of (...), it can be used as a multi-band pass filter.

There is also known a bandpass filter constructed by combining a plurality of λ / 2 dielectric resonators. In such a bandpass filter, not only the main frequency based on the resonance of the lowest order mode but also the , And shows a pass characteristic even at a frequency that is an integral multiple (2 times, 3 times, 4 times ...) Based on the resonance of the higher order mode. Therefore, such a type of bandpass filter can also be used as a multibandpass filter.

[0005]

Currently, there are many communication systems, both wired and wireless, but the frequency bands used in each of these communication systems are generally different from each other. On the other hand, information communication terminals capable of communication by a plurality of methods, represented by so-called dual band mobile phones, have been developed, and it is considered that the demand for such information communication terminals will further increase in the future. Therefore, in such an information communication terminal, it is necessary to use a plurality of band pass filters corresponding to each method or use the above-described multi band pass filter.

However, in the multi-bandpass filter utilizing the resonance of the higher-order mode as described above, the frequency of each passband is fixed to an odd multiple or an integral multiple of the resonance frequency of the lowest-order mode. It can be used only when the passbands corresponding to the respective systems are in odd multiples or integer multiples. Further, it is possible to bias the resonance frequency of the higher-order mode to some extent by adjusting the metallization pattern of each dielectric resonator, but such adjustment is limited, and the relationship between the two passbands is limited. It cannot be set freely.

Therefore, an object of the present invention is to provide a composite resonator having a plurality of resonance frequencies, in which at least two resonance frequencies can be arbitrarily set.

Another object of the present invention is to provide a bandpass filter having a plurality of passbands, in which at least two passbands of these passbands can be arbitrarily set. is there.

[0009]

A composite resonator according to the present invention has at least two coplanar lines provided on a dielectric substrate, and a transmission line (a live part, a hot part or a hot line) constituting one of the coplanar lines. (Sometimes called a line) is used as a ground pattern forming the other coplanar line. Further, the bandpass filter according to the present invention is characterized in that at least two passbands can be set to each other by using such a composite resonator.

FIG. 1 is a plan view schematically showing the basic structure of a coplanar line. As shown in FIG. 1, the coplanar line 10 includes a transmission line 11 provided on a dielectric substrate 13.
And a ground pattern 12 provided on the dielectric substrate 13 and provided on the same plane so as to sandwich the transmission line 11, thereby enabling resonance based on the length of the transmission line 11. Becomes For example, FIG. 2 (a)
As shown in FIG.
By short-circuiting to 2 and opening the other end, it functions as a λ / 4 resonator, and can make n · λ / 4 resonance (n: an odd number of 1 or more). On the other hand, as shown in FIG.
By shorting both ends to the ground pattern 12, it is possible to function as a λ / 2 resonator and perform m · λ / 2 resonance (m: an integer of 1 or more). Also, although not shown, even if both ends are opened, it similarly functions as a λ / 2 resonator.

FIG. 3 is a schematic diagram for explaining the principle of sharing a part of two coplanar lines with each other. Figure 3
As shown in, two transmission lines 11-1 and 11-2 are laid in parallel on the dielectric substrate 13, and these transmission lines 11-1 and
If ground patterns 12-1 and 12-2 are provided on the same plane on the dielectric substrate 13 so as to sandwich 11-2, 2
Two coplanar lines 10-1 and 10-2 can be constructed. In this case, in the coplanar line 10-1, the transmission line 11-1 is actually used as a transmission line, while the transmission line 1 is used at a frequency at which the transmission line 11-1 resonates.
1-2 is substantially used as the ground pattern, and in the coplanar line 10-2, the transmission line 11-2 is actually used as the transmission line, while the transmission line 11-2 is used at the frequency at which the transmission line 11-2 resonates. -1 is substantially used as the ground pattern.

According to the present invention, a plurality of resonance frequencies are obtained by differentiating the resonance frequencies of at least two coplanar lines that share a part of each other in this way. In this case, since the resonance frequencies of the two coplanar lines can be set independently of each other, each resonance frequency is fixed to an odd multiple or an integer multiple of the resonance frequency of the lowest order mode as in the conventional case. Will disappear. Therefore, the frequency band to be used can be suitably used as a bandpass filter for an information communication terminal that performs communication by a plurality of methods that are not in a relationship of odd multiples or integer multiples.

Therefore, the above object of the present invention comprises a dielectric substrate and first and second coplanar lines provided on the dielectric substrate, and at the first frequency, the first coplanar line is provided. The transmission line forming the line functions as a ground pattern forming the second coplanar line, and at a second frequency different from the first frequency, the transmission line forming the second coplanar line is This is achieved by a composite resonator that functions as a ground pattern forming the first coplanar line.

In a preferred aspect of the present invention, the first coplanar line functions as a λ / 4 resonator at the first frequency, and the second coplanar line has a λ / 4 resonator at the second frequency. It functions as a / 2 resonator.

The above object of the present invention also includes a dielectric substrate,
First to third metallization provided on the dielectric substrate, wherein both ends of the second metallization are connected to the first metallization and a periphery thereof is surrounded by the first metallization. The third metallization is achieved by a composite resonator characterized in that one end is connected to the first metallization, the other end is open, and the periphery is surrounded by the second metallization. .

In a preferred aspect of the present invention, the second metallization is substantially U-shaped or U-shaped.

In a further preferred aspect of the present invention, the third metallization is substantially I-shaped.

In a further preferred aspect of the present invention, there is further provided means for grounding the first metallization.

In a further preferred aspect of the present invention, the third metallization is λ at the first frequency.
/ 4 resonator transmission line, and at a second frequency different from the first frequency, the second metallization functions as a λ / 2 resonator transmission line.

[0020] In a further preferred aspect of the present invention, the second metallization functions as a ground pattern at the first frequency, and the first and third metallizations serve as a ground pattern at the second frequency. Function as.

The above object of the present invention also includes a dielectric substrate,
The first and second coplanar lines provided on the dielectric substrate, and the excitation electrodes that are connected to the input / output electrodes and excite the first and second coplanar lines. Means that the transmission line forming the first coplanar line functions as a ground pattern forming the second coplanar line, and the second coplanar line is formed at a second frequency different from the first frequency. Is achieved by a bandpass filter characterized in that the transmission line forming the above-mentioned function as a ground pattern forming the above-mentioned first coplanar line.

In a preferred embodiment of the present invention, the first coplanar line functions as a λ / 4 resonator at the first frequency, and the second coplanar line has a λ / 4 resonator at the second frequency. It functions as a / 2 resonator.

[0023] In a further preferred aspect of the present invention, a plurality of composite resonators each including the first and second coplanar lines are provided.

In a further preferred aspect of the present invention, there is further provided means for suppressing coupling between the composite resonators.

In a further preferred aspect of the present invention, the suppressing means comprises through-hole wiring.

The above object of the present invention also includes a dielectric substrate,
First to third metallization provided on the dielectric substrate, grounding means for grounding the first metallization, and excitation means for exciting the transmission line constituted by the second and third metallization. And the second metallization is
Both ends are connected to the first metallization and the periphery is surrounded by the first metallization, and the third metallization has one end connected to the first metallization and the other end open. This is achieved by a bandpass filter characterized in that the circumference is surrounded by the second metallization.

[0027] In a preferred aspect of the present invention, the exciting means comprises a fourth metallization provided on a layer different from the layer provided with the first to third metallizations on the dielectric substrate. Therefore, the transmission line can be capacitively excited.

In another preferred embodiment of the invention said excitation means comprises a fifth metallization connected to said second metallization and said third metallization, whereby inductively the transmission line. It is configured to be excitable.

In another more preferred aspect of the present invention, the fifth metallization is provided on the dielectric substrate.

In another more preferred aspect of the present invention, the fifth metallization is provided on a layer different from the layer provided with the first to third metallizations on the dielectric substrate. , And is connected to the second metallization and the third metallization via through-hole wiring.

According to the present invention, the length of the transmission line forming the first coplanar line and the length of the transmission line forming the second coplanar line are adjusted, or the length of the second metallization is adjusted. By adjusting the length of the third metallization, the resonance frequencies of these coplanar lines can be set independently of each other, and the resonance frequencies of the resonators using these metallizations as transmission lines can be set independently of each other. You can As a result, each pass band is not fixed to an odd multiple or an integral multiple of the resonance frequency of the lowest order mode, and it is possible to have a plurality of pass bands that are not in the odd multiple or integral multiple relationship. . Therefore, the frequency band to be used can be suitably used as a bandpass filter for an information communication terminal that performs communication by a plurality of methods that are not in a relationship of odd multiples or integer multiples.

[0032]

DETAILED DESCRIPTION OF THE INVENTION Referring to the accompanying drawings,
A preferred embodiment of the present invention will be described in detail.

FIG. 4 is a schematic perspective view schematically showing a bandpass filter 20 according to a preferred embodiment of the present invention, and FIG. 5 shows a state in which each dielectric substrate constituting the bandpass filter 20 is disassembled. It is a schematic exploded perspective view.

As shown in FIGS. 4 and 5, the bandpass filter 20 according to the present embodiment includes four laminated dielectric substrates 21-1 to 21-4 (collectively, the “laminated block 21”). It may be called)), and is a rectangular parallelepiped dielectric filter constituted by the metallization 22 formed on these surfaces. In addition, in FIGS. 4 and 5, the metallization 22 of the surfaces of the dielectric substrates 21-1 to 21-4 is
The hatched area indicates the metallized area.
The portion not subjected to the mark is shown in the color (white) of the paper. In addition, the bandpass filter 20 according to the present embodiment
Is plane-symmetric with respect to the target surface 23 shown in FIG.
Therefore, even when the bandpass filter 20 is viewed from the opposite side, it looks the same as in FIGS. 4 and 5. Moreover, although not particularly limited, it is preferable to use a silver paste as the metallization 22.

As shown in FIG. 5, metallization 22-1, 22-2 and 22- are formed on the side surfaces of the four dielectric substrates 21-1 to 21-4 constituting the laminated block 21 in the longitudinal direction. 3 are formed at common positions. Of these, the metallization 22-1 is used as an input / output electrode, and the metallizations 22-2 and 22-3 are used as ground electrodes. In this embodiment, the dielectric substrate 2
Metallizations provided on 1-1 and 21-4 are only these metallizations 22-1, 22-2 and 22-3,
Other surfaces are exposed.

On the dielectric substrate 21-2, in addition to the metallizations 22-1, 22-2 and 22-3 provided on the side surfaces,
Two metallizations 22-4 are provided on the upper surface. These two metallizations 22-4 are connected to the metallization 22-1 provided on one side surface and the metallization 22-1 provided on the other side surface, respectively, and serve as lead-out wiring, and at the same time, the dielectric material is formed. Board 21-
3 serves as an excitation electrode for the composite resonator provided on the upper part of FIG. The metallization is not formed on the other surface of the dielectric substrate 21-2 and is exposed.

On the dielectric substrate 21-3, in addition to the metallizations 22-1, 22-2 and 22-3 provided on the side surfaces,
A metallization 22-5 is provided on the upper surface. The metallization 22-5 is formed on the entire upper surface of the dielectric substrate 21-3 except for the notch 24 and the two slits 25 and 26 for preventing contact with the metallization 22-1 provided on both side surfaces. The ground potential is provided by contacting the metallizations 22-2 and 22-3 formed on both sides. As shown in FIG. 5, the slit portion 2
5 and 26 are substantially U-shaped, and the slit portion 26
Is provided in the area surrounded by the slit 25, the area of the metallized 22-5 surrounded by the slit 25 has a substantially U shape, and the area surrounded by the slit 26. Has a substantially I shape. Next, using the top view of the dielectric substrate 21-3, the metallization 22-
The shape of No. 5 will be described in more detail.

FIG. 6 is a top view of the dielectric substrate 21-3. In addition, FIG. 6 also shows the planar position of the metallization 22-4 when the dielectric substrates 21-1 to 21-4 are laminated.

As shown in FIG. 6, the metallization 22-5 formed on the upper surface of the dielectric substrate 21-3 includes slit portions 2
A substantially I-shaped region A surrounded by 6 and the slit portion 25
It can be divided into a substantially B-shaped region B surrounded by and a region C other than that. The regions A and B are the dielectric substrate 21.
-2 is capacitively excited by the metallization 22-4 provided at -2. Incidentally, in the example shown in FIG.
-4 has a portion overlapping the substantially I-shaped region A, but as long as the substantially I-shaped region A can be excited,
It is not necessary to provide such an overlap part.

As is apparent from FIG. 6, the metallization 22
In -5, the substantially I-shaped region A surrounded by the slit portion 26 is adjacent to the region C which has one end in contact with the region C which is the ground electrode and the other end which is open. If the region B to be processed is considered as a ground pattern,
As shown in (a), the portion consisting of the regions A and B can be regarded as a λ / 4 wavelength coplanar line having the region A as a transmission line. On the other hand, the substantially U-shaped region B surrounded by the slit portion 25 has both ends in contact with the region C which is the ground electrode. Therefore, if the regions A and C adjacent thereto are considered as the ground pattern. , Fig. 7
As shown in (b), the portion composed of the regions A, B, and C can be regarded as a λ / 2 wavelength coplanar line having the region B as a transmission line. In this way, the dielectric substrate 21-
3 and the metallization 22-5 formed on the upper surface thereof are 2
It functions as a composite resonator using two coplanar lines.

Therefore, n.lamda./4 resonance (n is an odd number of 1 or more) is possible for the coplanar line using the area A as the transmission line, and m.lamda. For the coplanar line using the area B as the transmission line. / 2 resonance (m: integer of 1 or more) is possible.

FIG. 8 is a diagram schematically showing the resonance characteristic of the coplanar line having the transmission line in the area A. The voltage waveform when λ / 4 resonance occurs and the case where 3λ / 4 resonance occurs 2 and the voltage waveform when 5λ / 4 resonance occurs. As shown in FIG. 8, in the coplanar line using the region A as the transmission line, n.lamda./4 resonance (n: an odd number of 1 or more) is possible. Therefore, by setting the length of the region A, Thus, one or more desired resonance frequencies can be obtained.

FIG. 9 is a diagram schematically showing the resonance characteristics of the coplanar line having the transmission line in the region B. The voltage waveform when the λ / 2 resonance occurs and the voltage when the λ resonance occurs. The waveform and the voltage waveform when the 3λ / 2 resonance occurs are shown. As shown in FIG. 9, in the coplanar line having the transmission line in the region B, m · λ / 2 resonance (m:
Since an integer of 1 or more) is possible, the desired resonance frequency of 1 or more can be obtained by setting the length of the region B.

In this case, since the length of the region A and the length of the region B can be set independently of each other, the resonance frequency of the coplanar line having the region A as the transmission line and the region B as the transmission line. The resonance frequency of the coplanar line can be set independently of each other. Therefore, in the bandpass filter 20 according to the present embodiment, each passband is not fixed at an odd multiple or an integral multiple of the resonance frequency of the lowest order mode as in the conventional case, and an odd multiple or an integer multiple. It is possible to have a plurality of pass bands that are not in a double relationship. As a result, the bandpass filter 20 according to the present embodiment can be suitably used as a bandpass filter for an information communication terminal that performs communication by a plurality of systems in which the frequency bands to be used are not odd multiples or integer multiples. It will be possible.

FIG. 10 is a graph showing the frequency characteristic of the bandpass filter 20. The frequency characteristic shown in FIG. 10 has a dielectric substrate 21-
The relative permittivity ε of 1 and 21-4 is about 50, the relative permittivity ε of the dielectric substrates 21-2 and 21-3 is about 92,
Each of the dielectric substrates 21-1 to 21-4 has a planar size of 8.0 mm × 3.5 mm, and the dielectric substrates 21-1 to 21-4
21-4 has a thickness of 0.4 mm, 0.8 mm,
0.2 mm and 0.4 mm, and metallization 2
2-5, the length and width of the substantially I-shaped region A surrounded by the slit portion 26 are 4.3 mm and 0.4, respectively.
mm, and the length and width of the substantially U-shaped region B surrounded by the slit portion 25 are 12.5 mm and 0.3, respectively.
It is a characteristic when it is mm. Here, the length of the region B is defined by the length along the center of the region B.

As shown in FIG. 10, the bandpass filter 20 according to this embodiment has four passbands (about 1 GHz, about 1.5 GHz, and 3 GHz).
About 2 GHz, about 3 GHz).

Of these, the pass band of about 1 GHz is
It is based on the resonance (λ / 2 resonance shown in FIG. 9) of the lowest mode of the coplanar line having the region B as the transmission line, and the region A is regarded as the ground pattern at the frequency. Regarding the pass bands of about 2 GHz and about 3 GHz, the second-order mode resonance (λ resonance shown in FIG. 9) and the third-order mode resonance (3λ / shown in FIG. 9) of the coplanar line having the region B as the transmission line, respectively. 2 resonance), and the resonance frequency is an integer multiple (2
2 times and 3 times).

On the other hand, the pass band of about 1.5 GHz is based on the resonance of the lowest order mode (λ / 4 resonance shown in FIG. 8) of the coplanar line having the area A as the transmission line, and the area at the frequency. B is regarded as a ground pattern.
Therefore, although not shown in FIG. 10, the frequency characteristics of the band pass filter 20 include 4.5 GHz and 7.5 G.
GH, which is the resonance frequency of the lowest mode such as Hz
Resonance of a higher mode equivalent to an odd multiple of z (3 shown in FIG.
A passband based on λ / 4 resonance, 5λ / 4 resonance, etc.) should appear.

As described above, according to this embodiment, by setting the length of the region A and the length of the region B, the resonance frequency of the coplanar line having the region A as the transmission line and the region B as the transmission line. Since the resonance frequency of the coplanar line can be set independently of each other, the frequencies of at least two pass bands can be set arbitrarily. Therefore, the bandpass filter 20 according to the present embodiment is
The frequency band to be used can be suitably used as a bandpass filter for an information communication terminal that performs communication by a plurality of methods that are not in the relationship of odd multiples or integer multiples.

As shown in FIG. 4, the bandpass filter 20 according to the above embodiment has dielectric substrates 21-1 to 21-1.
In the state where 21-4 are stacked, the stacked block 21
Although the metallization 22 is provided only on the side surface in the longitudinal direction, the metallization 22 may be provided on the other surfaces.

FIG. 11 shows a bandpass filter 2 according to an example in which a metallization 22 is provided on the other surface of the laminated block 21.
12 is a schematic perspective view showing 0 ', and FIG.
It is a schematic exploded perspective view which shows the state which decomposed | disassembled 1-1 to 21-4.

As shown in FIGS. 11 and 12, in the bandpass filter 20 ', the metallization 22-6 is provided on the upper surface of the dielectric substrate 21-1 constituting the uppermost layer, and each dielectric substrate 21-1 is provided. Metallization 22-7 is also provided on the side surfaces of 21-1 to 21-4 in the short side direction.
Although not shown, the dielectric substrate 21- constituting the lowermost layer
Metallization is also provided on the bottom surface of 4. In this way, when the metallization 22 is provided on the other surface of the laminated block 21 as well, the metallization 22-1 which is the input / output electrode and the metallization which is the ground electrode are formed on the upper surface of the dielectric substrate 21-1 forming the uppermost layer. A cutout 27 is required to prevent contact with 22-6. Similarly, although not shown, a cutout that prevents contact between the metallization 22-1 that is the input / output electrode and the metallization (not shown) that is the ground electrode is also formed on the bottom surface of the dielectric substrate 21-4 forming the lowermost layer. A part (not shown) is required.

Next, another preferred embodiment of the present invention will be described.

FIG. 13 is a schematic exploded perspective view showing an exploded state of each dielectric substrate constituting the bandpass filter 30 according to another preferred embodiment of the present invention. After stacking these dielectric substrates, there is no difference from the appearance of the bandpass filter 20 according to the above embodiment, and the appearance is as shown in FIG.

Bandpass filter 30 according to the present embodiment
Differs from the bandpass filter 20 according to the above embodiment in the excitation method for the composite resonator formed on the dielectric substrate 21-3, and other configurations are similar to those of the bandpass filter 20 according to the above embodiment. Is. Therefore, the same components as those of the bandpass filter 20 according to the above embodiment are designated by the same reference numerals,
A duplicate description will be omitted.

As shown in FIG. 13, the band pass filter 3
At 0, the metallization 22-4 provided on the dielectric substrate 21-2 is thinned from the middle. The thin metallization 22-8 serves as an extraction wiring and also as an excitation electrode for the composite resonator provided on the dielectric substrate 21-3.

FIG. 14 is a schematic sectional view taken along the line AA shown in FIG.

As shown in FIG. 14, the dielectric substrate 21-2
Are provided with four through-hole wirings 31-1 to 31-4. Of these, through-hole wiring 31-
Reference numerals 1 and 31-2 respectively connect the corresponding metallization 22-8 and the portion corresponding to the area A of the metallization 22-5 (indicated as 22-5 (A) in FIG. 14), and form through holes. The wirings 31-3 and 31-4 connect the corresponding metallization 22-8 and the portion corresponding to the region B of the metallization 22-5 (indicated by 22-5 (B) in FIG. 14), respectively. .

FIG. 15 is a top view of the dielectric substrate 21-3, showing the plane positions of the metallization 22-4, 22-8 and the through-hole wiring 31 when the dielectric substrates 21-1 to 21-4 are laminated. The plane positions of -1 to 31-4 are also shown together. Referring to FIG. 15, the substantially I-shaped region A surrounded by the slit portion 26 is a through hole wiring 31.
-1 or 31-2 inductively excited, and the substantially U-shaped region B surrounded by the slit portion 25 is inductively excited via the through-hole wiring 31-3 or 31-4. I understand.

Accordingly, also in the bandpass filter 30 according to the present embodiment, the coplanar line having the area A as the transmission line and the coplanar line having the area B as the transmission line can be excited, so that the length of the area A is increased. And area B
By adjusting the length of, it is possible to have a plurality of pass bands that are not in odd multiples or integer multiples.

Next, still another preferred embodiment of the present invention will be described.

FIG. 16 is a schematic exploded perspective view showing an exploded state of each dielectric substrate constituting the bandpass filter 40 according to still another preferred embodiment of the present invention. still,
After stacking these dielectric substrates, there is almost no difference from the appearance of the bandpass filter 20 'according to the above embodiment, and the appearance is as shown in FIG.

Bandpass filter 40 according to the present embodiment
Similarly to the bandpass filter 30 according to the above-described embodiment, is a type in which a composite resonator formed on the dielectric substrate 21-3 is inductively excited. However, according to the above-described embodiment in the arrangement of the metallization serving as an excitation electrode. Different from the band pass filter 30, the dielectric substrates 21-1 to 21-4
The point that the through-hole wiring 41 is provided is different from the band pass filter 30 according to the above-described embodiment. Since the other configurations are similar to those of the bandpass filter 30 according to the above-described embodiment, the same components as those of the bandpass filter 30 according to the above-mentioned embodiment are denoted by the same reference numerals, and the duplicate description will be omitted.

FIG. 17 is a top view of the dielectric substrate 21-3.

As shown in FIGS. 16 and 17, metallization 22-1 and metallization 2 are formed on the dielectric substrate 21-3.
A thin metallization 22-9 for connecting to the area B of 2-5
And a thin metallization 22-10 connecting the region A and the region B of the metallization 22-5. Therefore, for the coplanar line that uses the region B as the transmission line,
For the coplanar line which is excited through the metallization 22-9 and uses the region A as a transmission line, the metallization 22-
It will be excited via 9, 22-10. As described above, in this embodiment, the metallizations 22-9 and 22-10 to be the excitation electrodes are arranged on the dielectric substrate 21-3, so that the through-hole wiring 31 for connecting to the excitation electrodes can be omitted. It is possible.

As described above, also in the bandpass filter 30 according to the present embodiment, since the coplanar line having the area A as the transmission line and the coplanar line having the area B as the transmission line can be excited, the length of the area A is increased. Area B
By adjusting the length of, it is possible to have a plurality of pass bands that are not in odd multiples or integer multiples.

In this embodiment, as is apparent from FIG. 17, the region C of the metallization 22-5 provided on the dielectric substrate 21-3 is divided into two. However, in this embodiment, as shown in FIG. 16, each of the divided regions C is the uppermost dielectric substrate 21 via the through hole wiring 41.
Since it is connected to the metallization 22-6 provided on the upper surface of -1 or the bottom surface of the dielectric substrate 21-4, which is the lowermost layer, the ground potential is surely applied to any region. The divided region C is the dielectric substrate 21-
3, a metallization 22-2 provided on the side surface in the long side direction,
22-3 and the metallization 22 provided on the side surface in the short side direction
Since it is connected to the metallization 22-6 provided on the top surface of the dielectric substrate 21-1 and the bottom surface of the dielectric substrate 21-4 via -7, it is separated by the connection via the metallization 22-7. If the ground potential can be reliably applied to both of the regions C, the through hole wiring 4
1 may be omitted.

Next, another preferred embodiment of the present invention will be described.

FIG. 18 is a schematic exploded perspective view showing a state in which each dielectric substrate constituting the bandpass filter 50 according to still another preferred embodiment of the present invention is disassembled. Figure 1
As shown in FIG. 8, the bandpass filter 50 according to the present embodiment is a multistage filter in which two stages of the composite resonator according to the present invention are used.

Specifically, the bandpass filter 50 includes four dielectric substrates 51-1 to 51-4 (collectively referred to as "laminated block") and their surfaces. This is a rectangular parallelepiped dielectric filter configured by metallization formed on the. As shown in FIG.
Four dielectric substrates 51-1 to 5-5 forming a laminated block
Metallization 52 is provided on each of the side surfaces in the longitudinal direction of 1-4.
-1, 52-2 and 52-3 are formed at a common position. Of these, the metallize 52-1 is used as an input / output electrode, and the metallize 52-2 and 52-3 are used as ground electrodes. In addition, each dielectric substrate 5
Metallization 5 is provided on the side surfaces in the short side direction of 1-1 to 51-4.
2-7 are provided.

Furthermore, on the upper surface of the dielectric substrate 51-1,
A metallization 52-6, which is a ground electrode, is further provided on the entire surface excluding the cutout portion 57. The metallization 52-6 is prevented from coming into contact with the metallization 52-1 which is an input / output electrode by the cutout portion 57. Although not shown, the bottom surface of the dielectric substrate 51-4 is similar.
As will be described in detail below, the dielectric substrate 51-1 is provided with a large number of through-hole wirings 61 along the longitudinal direction.

Further, the dielectric substrate 51-2 is further provided with metallizations 52-4, 52-8, 52-9 on the upper surface. Of these, the metallization 52-4 is connected to the metallization 52-1 provided on one side surface and the metallization 52-1 provided on the other side surface, respectively, and plays a role as a lead wiring and also serves as a dielectric. It serves as an excitation electrode for the two composite resonators provided on the body substrate 51-3. Further, the metallization 52-8 serves as an excitation electrode that connects the two composite resonators provided on the dielectric substrate 51-3.
Further, the metallization 52-9 includes the through-hole wiring 61 provided on the dielectric substrate 51-1 and the dielectric substrate 51-1.
It is in contact with the metallization 52-7 provided on the second side surface, and is used as a ground electrode. As will be described in detail below, the dielectric substrate 51-2 is provided with a large number of through-hole wirings 62 along the longitudinal direction.

Further, the dielectric substrate 51-3 is provided with a metallization 52-5 on the upper surface. Metallize 52
-5 has a pattern in which the pattern of the metallization 22-5 shown in FIG. 6 is repeated twice, and details thereof will be described later. The metallization 52-5 is a metallization 52-which is an input / output electrode due to the notch 54.
Contact with 1 is blocked. As will be described in detail below, the dielectric substrate 51-3 is provided with a number of through-hole wirings 63 along the longitudinal direction.

Then, on the upper surface of the dielectric substrate 51-4,
Through-hole wiring 63 provided on the dielectric substrate 51-3
And a metallization 52-10 provided in contact with the metallization 52-7 provided on the side surface of the dielectric substrate 51-4, and a notch portion for preventing contact with the metallization 52-1 on the bottom surface (not shown). A metallization (not shown) that is a ground electrode is provided on the entire surface except for. As will be described in detail below, the dielectric substrate 51-4 is provided with a number of through-hole wirings 64 along the longitudinal direction.

Next, the shape of the metallization 22-5 will be described in more detail with reference to the top view of the dielectric substrate 21-3.

FIG. 19 is a top view of the dielectric substrate 51-3. Incidentally, FIG. 19 shows the dielectric substrates 51-1 to 51-4.
Metallization 52-4, 52- in the case of stacking
The plane positions of 8, 52-9 are also shown.

As shown in FIG. 19, the dielectric substrate 51-3
The metallization 52-5 formed on the upper surface of the metal is formed into a substantially I-shaped region A1 and A2 surrounded by the slit portion 56 and a substantially U-shaped region B1 and B2 surrounded by the slit portion 55.
And other areas C, and the areas A1,
A2, B1 and B2 are capacitively excited by metallizations 52-4 and 52-8 provided on the dielectric substrate 51-2. Therefore, if the shapes of the areas A1 and A2 are matched and the shapes of the areas B1 and B2 are matched, the composite resonator constituted by the areas A1, B1, C and the areas A2, B2, C are constituted. Since the characteristics of the composite resonator are the same, the composite resonator functions as a two-stage bandpass filter.

FIG. 20 is a schematic sectional view taken along the line BB shown in FIG.

As shown in FIG. 20, a dielectric substrate 51-1
2 to 51-4 are formed on the dielectric substrate 51-3.
A large number of through-hole wirings 61 to 64 between one composite resonator
Is provided. Since the ground potential is applied to all the through-hole wirings, the coupling between the two composite resonators is suppressed by this.

As described above, since the bandpass filter 50 according to this embodiment functions as a two-stage filter using two composite resonators, in addition to the effects of each of the above embodiments, the attenuation amount in the cutoff region is increased. Can be further increased.

Although the two composite resonators are capacitively excited in this embodiment, they may be inductively excited like the bandpass filters 30 and 40 according to the above embodiment. Absent.

Further, in this embodiment, the through-hole wirings 61 to 64 are used to prevent undesired coupling between the two composite resonators, but the distance between these composite resonators should be set large. Therefore, the coupling may be prevented without using the through hole wirings 61 to 64 and the metallizations 52-9 and 52-10. Even if the through-hole wiring is used, depending on the desired characteristics, a small number of through-hole wirings may be provided without using the metallization 52-9 and 52-10.

Furthermore, in this embodiment, two composite resonators are formed on the dielectric substrate 51-3, but three composite resonators are provided.
It is also possible to construct a bandpass filter having three or more stages by using the above composite resonator.

The present invention is not limited to the above embodiments, and various modifications can be made within the scope of the invention described in the claims, and these are also included in the scope of the present invention. It goes without saying that it is a thing.

For example, in each of the above embodiments, the laminated block is formed by using four dielectric substrates, but the number of the dielectric substrates forming the laminated block is an example, and the present invention is not limited to this. It is not limited to this.

In each of the above embodiments, the area B
Although the shape of is in a substantially U shape, it is not essential that it is U shape as long as both ends are grounded.
It may be U-shaped. Similarly, in each of the above embodiments, the shape of the region A is substantially I-shaped, but it is not essential that the region A is I-shaped as long as one end is grounded and the other end is open. It may have a shape or an S shape.

[0087]

As described above, according to the present invention, since the transmission line forming one coplanar line is used as the ground pattern forming the other coplanar line, at least two resonance frequencies are independent of each other. Can be set. Therefore, if a bandpass filter is constructed using such a composite resonator,
As in the past, each passband is no longer fixed at an odd multiple or an integral multiple of the resonance frequency of the lowest order mode, and it is possible to have multiple passbands that are not in the odd multiple or integral multiple relationship. Becomes Therefore, the frequency band to be used can be suitably used as a bandpass filter for an information communication terminal that performs communication by a plurality of methods that are not in a relationship of odd multiples or integer multiples.

[Brief description of drawings]

FIG. 1 is a plan view schematically showing a basic structure of a coplanar line.

2 (a) is a plan view schematically showing a coplanar line functioning as a λ / 4 resonator, and FIG.
FIG. 4 is a plan view schematically showing a coplanar line that functions as a λ / 2 resonator.

FIG. 3 is a schematic diagram for explaining the principle of sharing a part of two coplanar lines with each other.

FIG. 4 is a schematic perspective view schematically showing a bandpass filter 20 according to a preferred embodiment of the present invention.

FIG. 5 is a schematic exploded perspective view showing a state in which each dielectric substrate that constitutes the bandpass filter 20 is exploded.

FIG. 6 is a top view of a dielectric substrate 21-3 forming the bandpass filter 20.

7 (a) is a schematic diagram showing a state in which a composite resonator included in the bandpass filter 20 functions as a λ / 4 resonator, and FIG. 7 (b) is a bandpass filter. Two
It is a schematic diagram which shows the state in which the composite resonator contained in 0 is functioning as a (lambda) / 2 resonator.

FIG. 8 is a diagram schematically showing a resonance characteristic of a coplanar line having a region A as a transmission line.

FIG. 9 is a diagram schematically showing a resonance characteristic of a coplanar line having a region B as a transmission line.

FIG. 10 is a graph showing frequency characteristics of the bandpass filter 20.

FIG. 11 is a schematic perspective view schematically showing a bandpass filter 20 ′ which is a modified example of the bandpass filter 20.

FIG. 12 is a schematic exploded perspective view showing a state in which each dielectric substrate forming the bandpass filter 20 ′ is disassembled.

FIG. 13 is a schematic exploded perspective view showing an exploded state of each dielectric substrate that constitutes the bandpass filter 30 according to another preferred embodiment of the present invention.

14 is a schematic cross-sectional view taken along the line AA shown in FIG.

FIG. 15 is a top view of a dielectric substrate 21-3 forming the bandpass filter 30.

FIG. 16 is a schematic exploded perspective view showing a state in which each dielectric substrate constituting the bandpass filter 40 according to still another preferred embodiment of the present invention is disassembled.

FIG. 17 is a top view of a dielectric substrate 21-3 forming the bandpass filter 40.

FIG. 18 is a schematic exploded perspective view showing a state in which each dielectric substrate constituting the bandpass filter 50 according to still another preferred embodiment of the present invention is disassembled.

FIG. 19 is a top view of a dielectric substrate 51-3 forming the bandpass filter 50.

20 is a schematic cross-sectional view taken along the line BB shown in FIG.

[Explanation of symbols]

10, 10-1, 10-2 coplanar line 11, 11-1, 11-2 Transmission line 12, 12-1, 12-2 Ground pattern 13 Dielectric substrate 20, 20 ', 30, 40, 50 band pass filter 21 Laminated block 21-1 to 21-4 Dielectric substrate 22, 22-1 to 22-10 Metallization 23 Target surface 24,27 Notch 25,26 slit part 31-1 to 31-4, 41 Through-hole wiring 51-1 to 51-4 Dielectric substrate 52-1 to 52-10 Metallization 54, 57 Notch 55,56 slit part 61-64 through hole wiring

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Yasumasa Noguchi             2-12-10 Higashitomigaoka, Nara City, Nara Prefecture F-term (reference) 5J006 HB02 HB05 HB12 HB13 HB21                       HB22 JA01 JA05 JA09 JA10                       JA22 LA11 LA24 NA02 NA03                       NA04 NA08 NB07 NB10 NC03

Claims (18)

[Claims] 1. A dielectric substrate and first and second coplanar lines provided on the dielectric substrate, wherein a transmission line forming the first coplanar line is provided at a first frequency. The second coplanar line functions as a ground pattern, and at a second frequency different from the first frequency, the transmission line forming the second coplanar line forms the first coplanar line. A composite resonator characterized by functioning as a ground pattern. 2. At the first frequency, the first coplanar line functions as a λ / 4 resonator, and the second coplanar line functions as a λ / 4 resonator.
At the frequency of, the second coplanar line is λ / 2.
The composite resonator according to claim 1, which functions as a resonator. 3. A dielectric substrate, and first to third metallization provided on the dielectric substrate, wherein both ends of the second metallization are connected to the first metallization and a periphery thereof is Surrounded by the first metallization,
One end of the third metallization is connected to the first metallization, the other end is open, and the periphery is the second metallization.
A compound resonator characterized by being surrounded by a metallization of. 4. The composite resonator according to claim 3, wherein the second metallization is substantially U-shaped or U-shaped. 5. The composite resonator according to claim 3, wherein the third metallization is substantially I-shaped. 6. The composite resonator according to claim 3, further comprising means for grounding the first metallization. 7. The third metallization functions as a transmission line of a λ / 4 resonator at a first frequency,
7. The composite resonator according to claim 6, wherein the second metallization functions as a transmission line of the λ / 2 resonator at a second frequency different from the frequency of. 8. The second metallization functions as a ground pattern at the first frequency, and the second metallization functions as a ground pattern.
8. The composite resonator according to claim 7, wherein the first and third metallizations function as a ground pattern at the frequency of. 9. An excitation electrode connected to a dielectric substrate, first and second coplanar lines provided on the dielectric substrate, and input / output electrodes to excite the first and second coplanar lines. And at a first frequency, the transmission line forming the first coplanar line functions as a ground pattern forming the second coplanar line,
At a second frequency different from the first frequency,
The transmission line forming the second coplanar line is the first line.
Band-pass filter, which functions as a ground pattern that constitutes the coplanar line of the. 10. The first frequency at the first frequency
Of the coplanar line of λ / 4 functions as a λ / 4 resonator, and at the second frequency, the second coplanar line of λ /
The bandpass filter according to claim 9, which functions as a two-resonator. 11. The bandpass filter according to claim 9, wherein a plurality of composite resonators each including the first and second coplanar lines are provided. 12. The band pass filter according to claim 11, further comprising means for suppressing coupling between the composite resonators. 13. The bandpass filter according to claim 12, wherein the suppressing unit is a through-hole wiring. 14. A dielectric substrate, first to third metallizations provided on the dielectric substrate, grounding means for grounding the first metallization, and second and third metallizations. The second metallization has both ends connected to the first metallization and a periphery surrounded by the first metallization, and the third metallization is A band pass filter, one end of which is connected to the first metallization, the other end of which is open, and the periphery of which is surrounded by the second metallization. 15. The excitation means comprises a fourth metallization provided on a layer different from the layer provided with the first to third metallizations on the dielectric substrate, whereby the transmission line is formed. 15. The bandpass filter according to claim 14, wherein the bandpass filter is configured to be able to be excited capacitively. 16. The excitation means comprises a fifth metallization connected to the second metallization and the third metallization, whereby the transmission line is configured to be inductively excitable. The band pass filter according to claim 14, wherein the band pass filter is a filter. 17. The band pass filter according to claim 16, wherein the fifth metallization is provided on the dielectric substrate. 18. The fifth metallization is provided on a layer different from the layer provided with the first to third metallizations on the dielectric substrate, and the second metallization is provided through a through-hole wiring. 17. The band pass filter according to claim 16, wherein the band pass filter is connected to the first metallization and the third metallization.