KR100799467B1 - Dielectric filter, dielectric duplexer and communication apparatus - Google Patents

Abstract

In the dielectric filter of an ultra hetero-axial structure, an open face electrode is provided, and the capacitance between each open face electrode and the outer conductor is larger than the capacitance generated between adjacent open face electrodes. The area on the center side of the array of open surface electrodes is made larger than the area on the outside, and the electrode protrusions 85A, 85B, 85C are formed from the open surface electrodes 82A, 82C, and 83C, and the input / output electrode 74C is formed. It is formed in the short circuit surface of the excitation hole for interdigital coupling, and the resonance holes 72A-72C and 73A-73C of a short circuit surface are arrange | positioned at substantially equal intervals.

Dielectric block, resonant hole, open surface electrode, outer conductor, inner conductor, input / output electrode

Description

DIELECTRIC FILTER, DIELECTRIC DUPLEXER AND COMMUNICATION APPARATUS}

The present invention relates to a dielectric filter, a dielectric duplexer, and a communication device provided with the dielectric blocks.

Dielectric filters and dielectric duplexers applied to high frequency circuits are always required to provide miniaturized products.

Conventionally, various techniques for realizing miniaturization have been provided. Patent Literature 1 describes a biaxial structure in which a resonance hole is formed in a step shape, the axes of a large diameter hole portion and a small diameter hole portion are relatively largely eccentric to obtain a structure in which the resonance hole is curved. A dielectric filter of ultra hetero-axial structure is shown.

By arranging the resonators caused by the resonant holes in the dielectric block, the resonators are coupled to each other to generate attenuation poles. By setting the pitch between the resonance holes as necessary, the attenuation pole can be adjusted to a desired frequency.

The structural example of the dielectric duplexer which employ | adopted this conventional technique is shown in FIG. 1 is a diagram of a cross section parallel to the arrangement of the resonant holes, the upper side being an open side and the lower side being a short side.

The dielectric block 1 is provided with a plurality of resonance holes 2A to 2C and 3A to 3C, and inner conductors are formed on respective inner surfaces thereof. The electrode non-formation part 7 is provided in the edge part of the resonance hole 2A-2C, 3A-3C. The outer conductor 6 is formed on the outer surface of the dielectric block 1. Each of the resonant holes 2A to 2C and 3A to 3C has a large internal diameter on the open side (hereinafter referred to as a large diameter hole) and a small internal diameter on the short side (hereinafter referred to as a small diameter hole). It is negative.) It is a step hole. In this example, the distance between the resonance holes on the open surface side of the resonance holes 2A to 2C is larger than the distance between the resonance holes on the short circuit surface side (hereinafter referred to as cross-eyed shape). This configuration constitutes a transmission filter in which two resonance periods adjacent to each other by the resonance holes 2A to 2C are inductively coupled to each other. On the other hand, the resonance holes 3A to 3C are configured to have a distance between the resonance holes on the open surface side smaller than the distance between the resonance holes on the short circuit surface side (hereinafter, referred to as an external perspective shape). This configuration constitutes a reception filter in which two resonance periods adjacent to each other by the resonance holes 3A to 3C are capacitively coupled to each other.

The attenuation pole generated by the coupling of the resonance period is adjusted by setting an eccentric amount of the small diameter hole portion and the large diameter hole portion, a step ratio which is the ratio of the cross sectional area between the small diameter hole portion and the large diameter hole portion, and the like.

In the case of miniaturizing such a biaxial dielectric filter and dielectric duplexer, the gap between the resonators becomes narrower, and the wall thickness of the dielectric block becomes thinner. Therefore, the capacity of the resonance period increases. As a result, the attenuation pole of the filter characteristic deviates from the predetermined frequency and the predetermined filter characteristic is not obtained.

Further, Patent Document 2 discloses a configuration in which a resonance period is coupled by providing an open surface electrode on an open surface of a dielectric block. In a conventional dielectric filter having an open surface electrode, by adjusting the shape of the open surface electrode, the capacitance between the open surface electrodes is adjusted to realize a dielectric block having desired filter characteristics.

Patent Document 1: Japanese Patent Application Laid-Open No. 10-256807

Patent Document 2: Japanese Patent Application Laid-open No. Hei 6-097721

In the above-mentioned biaxial structure, the amount of eccentricity between the small diameter hole portion and the large diameter hole portion cannot be set more than the sum of the radius of the large diameter hole portion and the radius of the small diameter hole portion. Therefore, the range of eccentricity which can be taken is limited. In other words, when miniaturization of the conventional biaxial dielectric filter and dielectric duplexer is made smaller, it is difficult to realize the necessary filter characteristics even if the eccentricity is adjusted.

For example, in the case of eccentricity like an esotropy shape, this miniaturization may result in a lack of inductive coupling and the desired bandwidth may not be obtained. In addition, in the case of eccentricity as in the shape of an exotropy, due to this miniaturization, the capacitive coupling is excessive, the capacitive coupling is relatively strong, and desired filter characteristics may not be obtained.

In addition, depending on the spacing between the small-diameter holes, concentration of current may occur in a part of the short-circuit surface and deterioration of the Q value may occur.

In the case of providing the open surface electrode, if the size of the open surface electrode is further reduced, the gap between the adjacent open surface electrodes is narrowed. Therefore, the capacitance between the open surface electrodes increases. Then, as in the case of the super biaxial structure, the relative capacitive coupling of the resonance period becomes stronger, and it is difficult to realize necessary filter characteristics. In addition, by miniaturization, it was also difficult to miniaturize the pattern of the open surface electrode and to perform the pattern formation with high precision.

As described above, in the conventionally provided technology, there is a limit to the design of the filter characteristic according to the miniaturization.

Accordingly, an object of the present invention is to provide a dielectric filter or a dielectric duplexer which solves the above-described problems, further reduces the size of the related art, and can realize desired filter characteristics.

In addition, the miniaturized dielectric filter and dielectric duplexer provide a dielectric filter and a dielectric duplexer that allow the frequency of the attenuation poles to be easily adjusted and prevent the Q value of the resonator from deteriorating even by miniaturization.

According to the present invention, an open face electrode is provided in an emissive biaxial structure or a super biaxial dielectric filter, and an inductive coupling of two resonance periods by adjacent resonant holes is increased between each open surface electrode and the outer conductor. And the capacitance generated between adjacent open surface electrodes.

In such a configuration, the coupling between the two resonance periods by the adjacent resonance holes can be adjusted by the capacitance generated between each open surface electrode and the outer conductor and the capacitance generated between adjacent open surface electrodes. And since adjustment is made to strengthen the inductive coupling shortened by the miniaturization, the capacitive coupling of the resonance period strengthened by the miniaturization can be canceled and desired filter characteristics can be realized.

The present invention provides an open face electrode in a biaxial structure or a super biaxial dielectric filter having an oblique shape, and between the open face electrode and the outer conductor so that inductive coupling of two resonance periods by adjacent resonant holes increases. And the capacitance generated between adjacent open surface electrodes.

In such a configuration, the coupling between the two resonance periods by the adjacent resonance holes can be adjusted by the capacitance generated between each open surface electrode and the outer conductor and the capacitance generated between adjacent open surface electrodes. In addition, since adjustment is made so as to make the inductive coupling insufficient due to miniaturization, the capacitive coupling becomes relatively strong, and the excess capacitive coupling can be canceled, and desired filter characteristics can be realized.

In addition, in the present invention, the opening surface electrodes of the resonant holes located at both ends of the resonant holes arranged in parallel are arranged so that the projected area on the center side of the array is larger than the projected area on the outside of the array than the resonant holes.

This configuration generates capacitance not only between the open surface electrodes adjacent to the open surface electrodes at both ends, but also between the open surface electrodes of the resonator one step further. This capacitance then acts as a multipath capacitance, which makes it possible to control the position of the frequency of the attenuation pole.

Moreover, this invention is the direction of an adjacent open surface electrode from the edge edge vicinity perpendicular | vertical to the direction of the said array of at least one open surface electrode among the said open surface electrodes located in the both ends of the arranged resonance hole. It protrudes and forms the electrode protrusion which generate | occur | produces a capacitance with the open surface electrode different from the said open surface electrode.

With this configuration, in the open surface electrode provided with the electrode protrusion, multipath capacitance is generated not only between the adjacent open surface electrode but also with the open surface electrode of the resonator in the previous stage, and the attenuation electrode is also caused by the multipath capacitance. It becomes possible to control.

The present invention further protrudes in the direction of adjacent open surface electrodes from near edges perpendicular to the direction of the arrangement of the open surface electrodes positioned at both ends of the arranged resonant holes, respectively. Electrode protrusions for generating capacitance are formed respectively between the other open face electrodes, and the plurality of open face electrodes on the open face are arranged almost symmetrically in the direction of the arrangement of the resonance holes.

With this configuration, in the open surface electrode provided with the electrode protrusion, multipath capacitance is generated not only between the adjacent open surface electrode but also with the open surface electrode of the resonator in the previous stage, and the attenuation electrode is also caused by the multipath capacitance. It becomes possible to control. In addition, since the pattern shape of the open face electrode of the dielectric filter is substantially symmetrical, the circuit constant of the filter can be designed symmetrically in the input / output direction.

Moreover, this invention arrange | positions a some resonance hole so that the distance between the axial centers of the some resonance hole in the said short circuit surface may be equally spaced.

By such a structure, the space | interval between the small diameter hole parts in a short circuit surface becomes equal space | interval, and the current concentration of the conductor of a short circuit surface is suppressed. Then, deterioration of the Q value can be suppressed.

Moreover, this invention comprises a dielectric duplexer using either or both of the above-mentioned esotropy-shaped dielectric filter and the esotropy-shaped dielectric filter.

By such a configuration, a dielectric duplexer that realizes the required filter characteristics can be obtained while further miniaturization than before.

In addition, the present invention connects the input / output electrode for antenna connection with a conductor provided inside the excitation hole, and is provided on the short-circuit side of the mounting surface, and the excitation hole is interdigitated with an adjacent resonator. Let's do it.

With this configuration, since a portion acting as an outer conductor is formed on the open surface, it is possible to sufficiently take the ground. Therefore, the case for grounding is unnecessary at the time of mounting, and it can further miniaturize.

In addition, the present invention is the arrangement of the plurality of resonant holes only in the open surface electrodes which are connected to the inner conductors of the resonant holes corresponding to the terminal resonators among the plurality of open surface electrodes of the second dielectric filter. An electrode protrusion which protrudes in the direction of an adjacent open surface electrode from the vicinity of a short edge perpendicular to the direction of, and generates capacitance between the open surface electrode and another open surface electrode.

By such a configuration, an electrode protrusion is provided on the open face electrode positioned at the end when the filter in the emissive shape is used as a reception filter, so as to obtain a capacitance between the other open face electrodes and to be positioned at the ultra-short end. An electrode projecting portion is not formed in the open surface electrode, and the capacitance generated between the outer conductor is made relatively small. By this structure, the impedance between the input / output electrode for antenna connection and this open surface electrode can be made suitable for phase synthesis, and phase synthesis can be performed with high precision.

In addition, the present invention provides at least one of the dielectric filter and the dielectric duplexer in a high frequency circuit to constitute a communication device.

Effect of the Invention

According to the present invention, it is possible to obtain a dielectric filter, a dielectric duplexer, and a communication device in which the filters are realized, which are smaller in size than before.

1 is an overview of a dielectric duplexer according to an example of a conventional ultra hetero-axial structure.

2 is an external perspective view of the dielectric duplexer according to the first embodiment.

3 is a front view of the dielectric duplexer according to the first embodiment.

4 is a front view of an open face of the dielectric duplexer according to the second embodiment.

5 is a front view of an open face of the dielectric duplexer according to the third embodiment.

6 is a front view of a dielectric duplexer according to the fourth embodiment.

7 is a block diagram of a communication device according to the fifth embodiment.

8 is a frequency characteristic diagram of the dielectric duplexer according to the second embodiment.

<Description of the code>

1, 11: dielectric block

2, 3, 12, 13, 32, 33, 52, 53, 72, 73: resonance hole

14A: Aftershock hole 14B: Ground hole

6, 16: outer conductor 45, 65, 85: electrode protrusion

17, 18, 19, 54, 55: input / output electrode 20, 40, 60, 80: transmission filter

21, 41, 61, 81: Receive filter

22, 23, 42, 43, 62, 63, 82, 83: open surface electrode

7: electrode non-forming part

Very suitable examples for carrying out the present invention are shown below as the first embodiment. FIG. 2 (A) is an external perspective view of the dielectric duplexer of this embodiment, and FIG. 2 (B) is a sectional view taken along the AA section of FIG. 2 (A). In FIG. 2A, the front left side of the drawing is an open surface, and the top surface of the drawing is a mounting surface. In FIG.2 (B), the front side of a figure is a mounting surface side.

In the dielectric block 11, a plurality of resonant holes 12A to 12C and 13A to 13C having a stepped ultra hetero-axial structure are arranged successively. The transverse shape of each resonant hole is provided to have a substantially long circular shape, and an inner conductor is formed on each inner surface. The transverse shape is short in the arrangement direction of the resonant holes, long in the vertical direction, and long in the shape of a circle, and the length of the arrangement direction in the large hole diameter portion and the small hole diameter portion is coincident. By doing so, the length of the resonance direction of the dielectric block of the dielectric block is shortened.

The resonance holes 12A to 12C are formed in an emissive shape and used as a transmission filter to be used at the low frequency side of the duplexer. In addition, since the resonant holes 12B are arranged to be substantially coaxial with the large hole diameter portion and the small hole diameter portion, between the two resonators 12A and 12B adjacent to each other and between the resonators 12B and 12C, respectively, inductive coupling. do. Therefore, these resonant holes 12A to 12C constitute a filter having two attenuation poles on the high frequency side of the frequency.

In addition, the resonance holes 13A to 13C are externally shaped to be reception filters used at the high frequency side of the duplexer. In addition, since the resonant holes 13B are arranged to be substantially coaxial with the large hole diameter portion and the small hole diameter portion, the capacitive coupling between the two resonators 13A and 13B adjacent to each other and between the resonators 13B and 13C respectively. do. Therefore, these resonant holes 13A to 13C constitute a filter having two attenuation poles on the low side of the frequency.

In the dielectric block 11, the excitation hole 14A and the ground hole 14B are provided inside, and the outer conductor 16 is formed in the outer surface. The excitation hole 14A and the ground hole 14B both form inner conductors on the inner surface, and are disposed between the resonance hole 12C and the resonance hole 13A so as to be parallel to the resonance holes 12A to 12C and 13A to 13C. Doing. The inner conductor of the inner surface of the excitation hole 14A conducts to the outer conductor 16 on the front left side of the diagram of the dielectric block 11 and is formed separately from the outer conductor 16 on the inner right side of the figure. It is connected to the input / output electrode 18. This part is interdigitally coupled to the transmission filter and the reception filter as an input / output part for the antenna. The inner conductor of the inner surface of the ground hole 14B is short-circuited to the outer conductor at both ends. Since the excitation hole 14A and the ground hole 14B are formed with a ground conductor which conducts the outer conductor 16 on the open surface, there is no need to separately install a case as in the prior art, so that it can be further miniaturized. . On the outer surface of the dielectric block 11, an input / output electrode 17 for a transmission signal and an input / output electrode 19 for a reception signal are formed from the mounting surface to the side surface. The input / output electrodes 17 and 19 are formed so as to generate opposing capacitances with the inner conductors of the adjacent resonant holes, respectively.

3 (A) is an external view seen from the open surface in the first embodiment. 3 (B) is an external view seen from the short circuit surface in 1st Embodiment. The capacitance of the open surface electrode will be described below using these figures.

Open surface electrodes 22A to 22C and 23A to 23C are respectively connected to the plurality of resonant holes 12A to 12C and 13A to 13C, and the other open surface electrodes, external conductors, input / output electrodes, etc. It is installed separately. Here, since the open surface electrodes 22A to 22C and 23A to 23C have a simple rectangular shape, the pattern formation of the open surface electrode can be easily performed.

By providing the open surface electrodes 22A to 22C and 23A to 23C, the mutual capacitance CK is generated between the open surface electrodes. In addition, a magnetic capacitance CI is generated between the open surface electrode and the outer conductor. The mutual capacitance CK causes the coupling of the resonance period to be relatively capacitive, but the magnetic capacitance CI acts to weaken the capacitive coupling and to make the inductive coupling relatively strong, as opposed to the mutual capacitance. Therefore, the action of the mutual capacitance CK generated by providing an open surface electrode between two adjacent resonators can be canceled out. Therefore, the damping pole can also be controlled by appropriately setting the magnetic capacitance CI generated in each resonator.

The self capacitance CI can be adjusted by the distance to the outer conductor, the length of the adjacent side, etc. in each of the open surface electrodes. By adjusting the magnetic capacitance CI, the coupling of the resonance periods by each of the resonance holes 12A to 12C and 13A to 13C is set. By the setting, the bandwidth in the filter characteristics can be adjusted, and the inductance and the capacitiveness can be adjusted. In order to obtain a large magnetic capacitance CI by the open surface electrode, resonance is generally achieved by making the sum of the magnetic capacitances CI of each of the adjacent open surface electrodes larger than the value of the mutual capacitance CK between these open surface electrodes. Combination of terms can lead to induction. For example, the sum of the magnetic capacitance CI of the open surface electrode 22A and the magnetic capacitance CI of the open surface electrode 22B is determined between the open surface electrode 22A and the open surface electrode 22B. By setting it larger than the mutual capacitance CK, the coupling between the resonator by the resonator hole 12A and the resonator by the resonator hole 12B can be made relatively inductive than in the case where there is no open surface electrode.

As described above, since the magnetic capacitance CI and the mutual capacitance CK are adjusted in the emissive transmission filter 20, inductive coupling of the transmission filter 20 is assured, and in the filter characteristics, Attenuation poles are generated in the high range. In addition, since the self capacitance CI and the mutual capacitance CK are adjusted in the reception filter 21 having an external perspective shape, the capacitive coupling of the reception filter 21 is assumed to be appropriate, and the low frequency ( Attenuation poles are generated in i).

In the first embodiment, the area of the open surface electrode 22A is smaller than the resonance hole 12A on the outside, and is set larger on the open surface electrode 22B side, and the area of the open surface electrode 23C. In addition, it is smaller on the outer side than the resonance hole 13C and is set larger on the open surface electrode 23B. Thus, the attenuation pole of the filter characteristic can be adjusted more effectively also by adjusting an area.

Here, the effect of setting an area in this way is demonstrated. If the interval between resonance periods is small, inductive coupling may also occur between the adjacent resonators. The inductive coupling between these non-adjacent resonators needs to provide an open surface electrode to cancel the inductive coupling.

Therefore, here, by adjusting the area of the open surface electrode 22A and making the distance between the open surface electrode 22A and the open surface electrode 22C small, this open surface electrode 22A and the open surface electrode 22C are made. Capacity CM (hereinafter referred to as multipath capacity) is generated.

This multipath capacitance CM acts to weaken the inductive coupling of the resonance period and to make the capacitive coupling relatively strong, so that the inductive coupling between non-adjacent resonators can be canceled out. Therefore, the attenuation pole can also be controlled by appropriately setting the multipath capacitance CM generated in each resonator.

In order to adjust the multipath capacitance CM, the magnetic capacitance CI, and the mutual capacitance CK, for example, in the manufacturing process, an open surface electrode is formed relatively large. This can be done using several methods, such as a rooter.

As described above, by providing the open surface electrode, a dielectric duplexer which is smaller than the conventional one and has desired filter characteristics can be obtained even in a biaxial structure or a biaxial stepped resonant hole. Further, the degree of freedom in designing the arrangement of the large diameter hole portion on the open surface side and the arrangement of the small diameter hole portion on the short circuit surface side can be increased.

On the other hand, in this embodiment, the open surface electrode is not limited to the rectangular shape, and any shape may be applied as long as the magnetic capacitance and mutual capacitance are set as described above.

In addition, the input / output electrode for antenna connection is interdigitally coupled using an excitation hole. However, the electrode separated from the external conductor is not limited to this aspect, and is opposed to the inner conductor of any one resonance hole. It is good also as an input / output electrode, and is not limited to the shape of an electrode. The input electrode of the transmission filter and the output part of the reception filter may be interdigitally coupled using an excitation hole, and the present invention is applicable without being limited to the shape of the input / output electrode.

In addition, the cross-sectional shape perpendicular to the axial direction of the resonance hole and the excitation hole is not limited to an elongated circle shape, and the present invention can be applied to any shape such as a circular shape, a rectangular shape, and an elliptical shape, and the dimensions are also defined between the resonance holes. It doesn't have to be the same.

In addition, in this embodiment, although it was set as the step hole of a biaxial structure, it may be a simple biaxial structure with small eccentricity of a large diameter hole part and a small diameter hole part, and the step ratio and cross-sectional shape of a large diameter hole part and a small diameter hole part may be sufficient as it. Any may be sufficient. Moreover, the space | interval between resonance holes does not need to be constant. As described above, the present invention can be applied to any large diameter hole and small diameter hole.

In the present embodiment, the dielectric duplexer in which the transmission filter and the reception filter are arranged in a single dielectric block is shown. However, the present invention is not limited to the dielectric duplexer, and the dielectric filter has the same effect.

Next, the 2nd Embodiment which is very suitable for implementation of this invention is shown. 2nd Embodiment changes only the shape of the open surface electrode of said 1st Embodiment.

It is an external view seen from the open surface in 2nd Embodiment. In this embodiment, the electrode protrusion parts 45A, 45B, and 45C are provided in the open surface electrodes 42A, 42C, and 43C, respectively. The electrode protrusions 45A, 45B, and 45C each have a narrow straight line extending from the edges on the mounting surface side of the open surface electrodes 42A, 42C, and 43C to the sides of the edges in the direction of the center of each filter. It is formed in a shape. Thus, by forming a rectangle, pattern formation can be performed easily. The electrode protrusions 45A, 45B, and 45C may be slightly shifted to the upper surface side or the lower surface side in this FIG. 4. Any shape may be used as long as it does not conduct with other open surface electrodes, external conductors, input / output electrodes, or the like.

The capacitance of the open surface electrodes 42A to 42C, 43A to 43C and the electrode protrusions 45A, 45B and 45C will be described below using this drawing.

By forming the open surface electrodes 42A to 42C and 43A to 43C, the mutual capacitance CK is generated between the open surface electrodes. In addition, a magnetic capacitance CI is generated between the open surface electrode and the outer conductor. The mutual capacitance CK causes the coupling of the resonance period to be relatively capacitive, but the magnetic capacitance CI acts to weaken the capacitive coupling and to make the inductive coupling relatively strong, as opposed to the mutual capacitance. Therefore, the action of the mutual capacitance CK generated by providing an open surface electrode between two adjacent resonators can be canceled out. Therefore, the attenuation pole is obtained by appropriately setting the magnetic capacitance CI generated in each resonator, determining the coupling degree of the resonance period.

In this second embodiment, the electrode projecting portions 45A, 45B, and 45C are provided in the open surface electrodes 42A, 42C, and 43C, respectively. The electrode protrusions 45A, 45B, and 45C generate a multipath capacitance CM between the non-adjacent open surface electrodes and act as multipath electrodes. Therefore, the attenuation pole of the filter characteristic can be adjusted also with the shape of these electrode protrusion part 45A, 45B, 45C.

Here, the effect by this electrode protrusion 45A, 45B, 45C is demonstrated based on the frequency characteristic diagram of FIG. FIG. 8A is an example showing the frequency characteristic in the transmission filter 40, and FIG. 8B is an example showing the frequency characteristic in the reception filter 41. As shown in FIG. 8 (A) and 8 (B) all show frequency characteristics in each case of the presence or absence of electrode protrusions, and the dotted line indicates that there is no electrode protrusion in the solid line and no multipath capacitance (CM) occurs. The case where an electrode protrusion part exists and a multipath capacitance CM generate | occur | produces is shown.

In general, when the interval between resonance periods is small, inductive coupling may be generated even between non-adjacent resonators. The inductive coupling between these non-adjacent resonators must provide an open surface electrode to offset the inductive coupling.

Therefore, in the transmission filter 40, the electrode protrusion part 45A and the electrode protrusion part 45B protrude from each opening surface electrode so that 42 A of opening surface electrodes and 42 C of opening surface electrodes may adjoin. Then, the multipath capacitance CM is generated between the electrode protrusions 45A and 45B. This multipath capacitance CM acts to weaken the inductive coupling of the resonance period and to make the capacitive coupling relatively strong, so that the inductive coupling between non-adjacent resonators can be canceled out. Therefore, the attenuation pole can be controlled by appropriately setting the multipath capacitance CM generated in each resonator.

Specifically, in the transmission filter 40, when there are no electrode protrusions, two generated between the resonance holes 32A and 32B and the resonance holes 32B and 32C as shown by the solid line shown in FIG. Attenuation poles may be too far apart to satisfy required characteristics. Thus, by obtaining the multi-pass capacitance CM by using the electrode protrusions, two generated between the resonant holes 32A and 32B and between the resonant holes 32B and 32C as shown by the dotted line shown in Fig. 8A. The attenuation poles of the dog can be approached to some extent. When there is a multipath capacitance CM, two attenuation poles can be approached as shown in the figure, and the attenuation can be sharpened to increase the attenuation amount.

In addition, when the electrode protrusions are provided together with the open surface electrodes positioned at both ends of the resonant holes arranged in this manner, and the open surface electrodes 42A and 42C are similarly symmetrically arranged, Since the filter constant can also be set symmetrically in the input / output direction, the design becomes easy.

In the reception filter 41, the electrode projecting portion 45C is projected from the opening surface electrode 43C so that the opening surface electrode 43A and the opening surface electrode 43C are close to each other. Then, a multipath capacitance is generated between the open surface electrode 43A and the electrode protrusion 45C. This multipath capacitance CM can cancel the inductive coupling between resonators that are not adjacent to each other. Therefore, the attenuation pole can be controlled by appropriately setting the multipath capacitance CM generated in each resonator.

Specifically, in the reception filter 41, in the absence of the electrode protrusion 45C, as shown by the solid line shown in Fig. 8B, between the resonance holes 33A and 33B and the resonance holes 33B and 33C. The two attenuation poles generated at s almost coincide with each other and do not satisfy the required characteristic. Thus, by using the electrode protruding portion 45C, the multipath capacitance CM is obtained as shown by the dotted line shown in Fig. 8B, so as to provide a gap between the resonance holes 33A and 33B and the resonance holes 33B and 33C. Keep the attenuation poles away. When there is a multipath capacitance CM, two attenuation poles generated between the resonance holes 33A and 33B and between the resonance holes 33B and 33C can be relatively different from each other, so that the required amount of attenuation can be obtained. It is possible to sharpen the attenuation or increase the amount of attenuation.

In this way, if the electrode protrusion 45C is provided only at the opening surface electrode 43C of the resonator of the final stage of the reception filter 41, the attenuation pole can be controlled and the first stage of the reception filter 41 can be controlled. In the resonator 43A, the capacitance generated between the external conductor can be made relatively small, and the impedance between the input / output electrode for antenna connection and this open surface electrode can be made suitable for phase synthesis, and the phase synthesis Can be performed with high precision.

In the present embodiment, on the transmission filter 40, both the first stage resonator and the final stage resonator are provided with electrode protrusions on the open surface electrodes, and the receive filter 41 has the open surface electrodes 43C of the final stage resonators. Although only the electrode protrusions were formed, the electrode protrusions may be formed on both the resonator of the first stage of the receiving filter 41 and the open surface electrodes of the resonator of the final stage, or may be formed on only one of them. Further, the electrode projecting portion may be provided only at the open surface electrode of either of the first end and the last end of the transmission filter 40.

In order to adjust this multipath capacitance CM, an electrode protrusion part is formed in a manufacturing process comparatively long, for example, and the length of an electrode protrusion part may be adjusted using various methods, such as a laser and a luther, in an adjustment process.

Next, the 3rd Embodiment which is very suitable for implementation of this invention is shown. In the third embodiment, the shape of the open surface electrode of the second embodiment is further changed.

It is an external view seen from the open surface in 3rd Embodiment. In this embodiment, the open surface electrodes 62A to 62C and 63A to 63C are provided in the plurality of resonant holes 52A to 52C and 53A to 53C, respectively. In addition, the electrode protrusions 65A, 65B, and 65C are provided on the open surface electrodes 62A, 62C, and 63C. Here, the open surface electrodes 62B, 63A, 63B have a rectangular shape.

Here, in the transmission filter 60, the electrode protrusion parts 65A and 65B are provided in the side facing the mounting surface of the upper surface of FIG. Moreover, in the reception filter 61, the electrode protrusion part 65C is provided in the mounting surface side of the lower surface of FIG.

In the transmission filter 60, by arranging the electrode protrusions 65A and 65B on the side opposite to the mounting surface in this manner, a multipath capacitance CM is generated between the open surface electrodes 62A and 62C, The magnetic capacitance CI of the open surface electrode 62A can be made relatively large. Usually, since the input / output electrode 54 is formed on the mounting surface side of the open surface electrode 62A, not the outer conductor, the effective dielectric constant around the input / output electrode 54 is substantially reduced. Therefore, even if the electrode protrusion is formed on the mounting surface side of the open surface electrode 62A, for example, the effect of increasing the self capacitance CI of the open surface electrode 62A does not occur. By providing 65A) on the side opposite to the mounting surface, the magnetic capacitance CI of the open surface electrode 62A can be made relatively large.

In the receiving filter 61, the electrode protrusion 65C is disposed on the mounting surface in this manner, so that the capacitance (external coupling capacitance) Ce between the open surface electrode 63C and the input / output electrode 55 is increased. It may be.

In the present embodiment, on the other hand, in the transmission filter 60, the electrode protrusions 65A, 65B are provided on the side facing the mounting surface, and in the reception filter 61, the electrode protrusions 65C are provided on the mounting surface side. . However, the present invention is not limited to this aspect, and the electrode protrusion may be used on either the mounting surface side or the side opposite to the mounting surface, regardless of the transmission filter and the reception filter.

Next, the 4th Embodiment which is very suitable for implementation of this invention is shown. 4th Embodiment makes the space | interval of the resonance hole of said 3rd Embodiment different.

FIG. 6 (A) is an external view seen from the open face in the fourth embodiment. FIG. 6B is an external view seen from the short-circuit surface in 4th Embodiment. In this embodiment, the plurality of resonant holes 72A to 72C and 73A to 73C are arranged at substantially equal intervals in the short circuit surface, and the open surface electrodes 82A to 82C and 83A to 83C and the electrode protrusion 85A on the open surface, respectively. , 85B, 85C) are installed. By providing the open surface electrodes 82A to 82C and 83A to 83C, mutual capacitance is generated between the open surface electrodes. In addition, a magnetic capacitance is generated between the open surface electrode and the outer conductor. In addition, multi-pass capacitance is generated by the electrode protrusions 85A, 85B, and 85C. The mutual capacitance causes the coupling of the resonance period to be relatively capacitive, but the magnetic capacitance, in contrast to the mutual capacitance, acts to weaken the capacitive coupling and to make the inductive coupling relatively strong. The action of the mutual capacitance generated by providing an open surface electrode between the resonators can be counteracted. Therefore, the magnetic capacitance generated in each resonator is appropriately set. In addition, the inductive coupling between non-adjacent resonators can be canceled by the multipath capacitance, so that the attenuation pole can be controlled by appropriately setting the multipath capacitance.

Here, the spaces between the resonant holes 72A to 72C and the resonant holes 73A to 73C on the short-circuit surface are arranged at substantially equal intervals, respectively. Therefore, the opening surface electrodes 82A-82C in the transmission filter 80 are comparatively large, and the opening surface electrodes 83A-83C in the reception filter 81 are arranged relatively narrowly.

In this manner, when the small-diameter holes at the short-circuit side are disposed at substantially equal intervals, current flows almost uniformly to the resonant holes on the short-circuit side and the outer conductor of the short-circuit side, whereby current concentration can be suppressed. Therefore, the Q value as the whole dielectric duplexer can be made the best.

In addition, since the small diameter hole portion on the short-circuit side is arranged at substantially equal intervals, the large diameter hole portion on the open side is largely limited, but the magnetic capacitance is obtained by the open surface electrode, thereby reducing the eccentricity of the resonance hole. The desired attenuation pole can be obtained.

Next, FIG. 7 is a block diagram showing the configuration of the communication apparatus as the fifth embodiment which is very suitable for the embodiment of the present invention. In FIG. 7, a dielectric duplexer having the configuration shown in the fourth embodiment described above is used as the duplexer DPX. On the circuit board, a transmission circuit and a reception circuit are configured, and a transmission circuit is connected to an input / output electrode for transmission signal in the transmission filter of the duplexer DPX, and the input / output for reception signal in the reception filter of the duplexer DPX. The duplexer DPX is mounted on the circuit board so that the receiving circuit is connected to the electrode and the antenna ANT is connected to the input / output electrode for antenna connection.

Claims (11)

An external conductor is provided on the other surface except one surface of the substantially rectangular parallelepiped dielectric block, and an input / output electrode separated from the external conductor is provided on the mounting surface with one surface perpendicular to the one surface as the mounting surface. The one surface on which the outer conductor of the dielectric block is not provided is an open surface, the surface opposite to the open surface is a short circuit surface, penetrates between the open surface and the short circuit surface in the dielectric block, Step-shaped holes having a large cross-sectional area on the side and a small cross-sectional area on the short-circuit side are arranged in parallel to the mounting surface at least three consecutively, and inner conductors are provided on the inner surfaces of the plurality of holes. In the dielectric filter, each of which is a resonance hole, Among the resonant holes at both ends of the above-mentioned resonant holes, the shaft center on the open surface side of the at least one resonance hole and the shaft center on the short-circuit side are shifted. The plurality of resonance holes are arranged so that the distance between the shaft centers on the open surface side of the resonance holes at both ends of the arranged resonance holes is longer than the distance between the shaft centers on the short circuit surface side, On the open surface, an open surface electrode which is separated from the outer conductor and is connected to each inner conductor is provided in each of the plurality of resonance holes, A dielectric filter characterized in that the capacitance generated between each open surface electrode and an outer conductor and the capacitance generated between adjacent open surface electrodes are defined so that the inductive coupling of two resonance periods by adjacent resonance holes increases. An external conductor is provided on the other surface except one surface of the substantially rectangular parallelepiped dielectric block, and an input / output electrode separated from the external conductor is provided on the mounting surface with one surface perpendicular to the one surface as the mounting surface. The one surface on which the outer conductor of the dielectric block is not provided is an open surface, the surface opposite to the open surface is a short circuit surface, penetrates between the open surface and the short circuit surface in the dielectric block, Step-shaped holes having a large cross-sectional area on the side and a small cross-sectional area on the short-circuit side are arranged in parallel to the mounting surface at least three consecutively, and inner conductors are provided on the inner surfaces of the plurality of holes. In the dielectric filter, each of which is a resonance hole, Among the resonant holes at both ends of the above-mentioned resonant holes, the shaft center on the open surface side of the at least one resonance hole and the shaft center on the short-circuit side are shifted. The plurality of resonance holes are arranged such that the distance between the shaft centers on the short-circuit surface side of the resonance holes at both ends of the arranged resonance holes is longer than the distance between the shaft centers on the open surface side, On the open surface, an open surface electrode is formed in each of the plurality of resonant holes, which is separated from the outer conductor and is connected to each of the inner conductors. A dielectric filter characterized in that the capacitance generated between each open surface electrode and an outer conductor and the capacitance generated between adjacent open surface electrodes are defined so that the inductive coupling of two resonance periods by adjacent resonance holes increases. 3. The opening face electrode located at both ends of the arranged resonance holes has an area at the center side of the arrangement more than the resonance hole provided with the inner conductor through which the opening face electrodes are conducted. A dielectric filter arranged so as to be larger than an area of the outside of the array. The said open surface electrode located in the both ends of the said arranged resonance hole of Claim 1 or 2 which adjoins from near the edge of the edge perpendicular | vertical to the direction of the said arrangement | positioning of at least one open surface electrode. A dielectric filter protruding in the direction of an open surface electrode, wherein an electrode protrusion is formed between the open surface electrode and an open surface electrode different from the open surface electrode. The method according to any one of claims 1 to 3, wherein the edges protrude in the direction of adjacent open surface electrodes, respectively, from near edges perpendicular to the direction of the arrangement of the open surface electrodes positioned at both ends of the arranged resonance holes. Electrode protrusions each generating a capacitance between the open surface electrode and the other open surface electrode; A plurality of the open surface electrodes on the open surface are formed so as to have a substantially symmetrical arrangement in the direction of the arrangement of the resonance holes. The dielectric filter according to claim 1 or 2, wherein the plurality of resonance holes are arranged such that the distance between the shaft centers on the short-circuit side of the plurality of resonance holes is equally spaced. Input / output electrode for antenna connection which comprises first and second dielectric filters in a single dielectric block, outputs an output signal from the first dielectric filter, and inputs an input signal to the second dielectric filter In the dielectric duplexer provided between the first and second dielectric filters, At least one of a 1st dielectric filter or a 2nd dielectric filter was used as the dielectric filter of Claim 1 or 2, The dielectric duplexer characterized by the above-mentioned. The dielectric filter according to claim 1 or 2 is formed in a single dielectric block as the first and second dielectric filters, the output signal from the first dielectric filter is output, and the second dielectric filter is used. In the dielectric duplexer provided with the input-output electrode for antenna connection which inputs the input signal to a between the 1st, 2nd dielectric filters, In the first dielectric filter, the plurality of resonance holes are arranged such that the distance between the shaft centers on the open surface side of the resonance holes at both ends of the arranged resonance holes is longer than the distance between the shaft centers on the short circuit surface side, The plurality of resonance holes are arranged in the second dielectric filter so that the distance between the shaft centers on the short-circuit side of the resonance holes at both ends of the arranged resonance holes is longer than the distance between the shaft centers on the open surface side. Dielectric duplexer. 8. A hole according to claim 7, wherein a hole penetrating from an intermediate position of said first and second dielectric filters on said open surface to an opposite position of said short-circuit surface is disposed, and an inner conductor is formed on an inner surface of said hole. Installed in the opening to conduct with the outer conductor to form an excitation hole, The electrode separated from the outer conductor from the mounting surface to the short-circuit surface is conducted with the inner conductor provided inside the excitation hole so as to be the input / output electrode for the antenna connection. A dielectric duplexer characterized by interdigital coupling with a resonator by adjacent resonance holes. 10. The method of claim 9, wherein, among the plurality of the open surface electrodes of the second dielectric filter, only the open surface electrodes conducting with the inner conductors of the resonant holes corresponding to the terminal resonators, A dielectric formed by protruding in the direction of an adjacent open surface electrode from near the short edge perpendicular to the direction of the array and generating a capacitance between the open surface electrode and another open surface electrode; Duplexer. A communication apparatus comprising the dielectric filter of claim 1 or 2 or the dielectric duplexer of claim 7 provided in a high frequency circuit section.

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