JP3909646B2 - Dielectric filter, duplexer and multiplexer - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a dielectric filter formed by forming a plurality of resonators in a dielectric block, a duplexer, and a multiplexer.
[0002]
[Prior art and problems to be solved by the invention]
Conventionally, a multistage resonance type dielectric filter formed using a ceramic dielectric is widely used to constitute an electronic circuit such as a mobile radio communication device such as an automobile phone or a mobile phone, a cordless phone, and a sanitary communication device. ing.
[0003]
In this type of dielectric filter, a plurality of dielectric resonators are formed in a rectangular parallelepiped-shaped dielectric block made of a ceramic dielectric, and these dielectric resonators are electromagnetically coupled to each other. For example, those described in JP-A-10-93305 and JP-A-8-512187 are known.
[0004]
The dielectric filter is disposed between an antenna of a wireless communication device such as a mobile phone or a car phone and a transmission circuit system and a reception circuit system, and outputs a transmission signal having a predetermined transmission frequency to the transmission circuit system. Therefore, it is used as a duplexer having a function of outputting a reception signal having a predetermined frequency from a signal received by an antenna to a reception circuit system.
[0005]
FIG. 14 shows a perspective view of a dielectric filter (duplex filter) described in JP-A-8-512187. A single dielectric block 202 having a rectangular parallelepiped shape is formed with ten through holes 203 to 212 penetrating from one surface (upper surface in FIG. 14) to the other surface (lower surface in FIG. 14). Has been. These through holes have an elliptical cross-sectional shape and are arranged in a line in the longitudinal direction of the dielectric block 202. An inner conductor 214 is formed on the inner wall surface of each of the through holes 203 to 212. Further, outer conductors 215 are formed on the lower surface and side surfaces of the dielectric block 202. The through holes 203 to 212 and the inner conductor 214 together with the outer conductor 215 and the dielectric block 202 form ten dielectric resonators arranged in a line. The inner conductor 214 is electrically open (separated) from the outer conductor 215 on the upper surface, and is electrically short-circuited (conducted) with the outer conductor 215 on the lower surface.
[0006]
In the conventional dielectric filter having the above structure, the side surface A located on the front side in FIG. 14 is used as a mounting surface for soldering to a mounting substrate such as a printed circuit board. In this dielectric filter, the dielectric constant of the dielectric block 202 is ε. _r And the sectional area of the dielectric block in the direction parallel to both the axial direction (vertical direction) and the arrangement direction (longitudinal direction of the dielectric block 202) of the through holes 203 to 212 (in FIG. 14, the height of the dielectric block 2). If the height is H and the length is W, the cross-sectional area is H × W), and a TE mode spurious signal having a frequency fs is determined. When the spurious frequency fs is close to a harmonic that is twice or three times the resonance frequency of the dielectric resonator, it adversely affects the operation stability of the receiving circuit system and the transmitting circuit system. In order to avoid such an influence, in the case of the above conventional dielectric filter, the size of the dielectric block 202, that is, the outer dimension of the dielectric filter must be changed in order to keep the resonance peak of the spurious frequency away from the harmonic. did not become.
[0007]
In order to solve such a problem, Japanese Patent Application Laid-Open No. 11-136003 discloses that the dielectric block is divided into a plurality of units having a plurality of through holes, and the sectional area (H × W) of the dielectric block is calculated. It has been proposed to change the spurious frequency of the TE mode by changing it. However, such a measure is disadvantageous in terms of manufacturing cost because it increases the number of parts and requires a means for mechanically and electrically joining each other's units. In addition, the size of the dielectric filter tends to increase, and it is difficult to meet the recent demand for miniaturization.
[0008]
On the other hand, it is conceivable to add a trap circuit as a method of suppressing spurious as described above. FIG. 15 shows an exploded perspective view of a dielectric filter to which a trap circuit is added. FIG. 16 is an equivalent circuit diagram of this dielectric filter. A dielectric filter 300 in which dielectric resonators are arranged in three stages is bonded onto a dielectric mounting substrate 302. A pair of input / output electrodes 306 and 307 are formed on the side surface (lower surface in FIG. 15) of the dielectric filter 300 so as to be insulated from the outer conductor 305 at positions corresponding to the dielectric resonators 304A and 304B at both ends. . On the other hand, an earth conductor 310 and a pair of input / output electrodes 316 and 317 insulated from the earth conductor are formed on the upper surface of the dielectric substrate 302. The outer conductor 305 of the dielectric filter 300 is connected to the ground conductor 310 on the upper surface of the dielectric mounting substrate, and the input / output electrodes 306 and 307 of the dielectric filter 300 are connected to the input / output electrodes 316 and 317 on the upper surface of the dielectric substrate. ing.
[0009]
The input / output electrode 317 also serves as a trap coupling electrode, and has an extending portion 317a for the coupling electrode. One electrode of the chip capacitor 320 is joined to the extending portion, and the other electrode of the capacitor 320 is connected to the inner conductor of the trapping dielectric resonator 324 via the connection terminal 322. The outer conductor of the trapping dielectric resonator 324 is connected to the ground conductor 310 of the substrate 302. Such a dielectric filter to which traps are added is described in, for example, Japanese Patent Application Laid-Open No. 7-245505.
[0010]
As described above, in order to add a trap, it is necessary to add many parts such as a dielectric resonator, a capacitor, and a connection terminal, and solder for incorporating such many parts in a predetermined position. Work such as attaching is necessary. Therefore, although spurious can be suppressed, it is difficult to reduce the size of the apparatus, and there is a problem that the component cost and the manufacturing cost are increased.
[0011]
Therefore, the present invention can obtain good spurious characteristics without assembling the dielectric block into a plurality of units, changing the outer dimensions of the dielectric block, or increasing the number of parts, and also assembling. An object of the present invention is to provide a dielectric filter capable of reducing the manufacturing cost.
[0012]
Another object of the present invention is to provide a duplexer and a multiplexer using such a dielectric filter.
[0013]
[Means for Solving the Problems]
According to the present invention, the above object is achieved as follows:
A pair of first and second end faces, a plurality of side faces crossing the first and second end faces, and a plurality of parallel ends extending between the first and second end faces A dielectric block having a plurality of through holes; an inner conductor formed on an inner surface of the plurality of through holes of the dielectric block; an outer conductor formed on the side surface and the second end surface of the dielectric block; A plurality of λ / 4 resonators are formed including
The plurality of λ / 4 resonators are arranged along a first side surface and a second side surface forming a pair of the plurality of side surfaces,
A pair of input / output electrodes are arranged insulated from the outer conductor;
A non-conductive pattern portion extending from the non-conductive region of the first end surface to the second end surface is formed on the first side surface and / or the second side surface, and the non-conductive pattern portion is The λ / 4 resonator is connected to the non-conductive region within a predetermined range with respect to the arrangement direction of the λ / 4 resonator, and the predetermined range is centered on the center of the dielectric block with respect to the arrangement direction of the λ / 4 resonator. In the range of 1/2 times the size of the body block And the non-conductive pattern portion functions as a λ ′ / 4 slot line resonator with respect to the wavelength λ ′ of the lower harmonic of the λ / 4 resonator. A dielectric filter characterized by
Is provided.
[0014]
In addition, according to the present invention, the above-mentioned object is achieved as follows:
A pair of first and second end faces, a plurality of side faces crossing the first and second end faces, and a plurality of parallel ends extending between the first and second end faces A dielectric block having a plurality of through holes; an inner conductor formed on an inner surface of the plurality of through holes of the dielectric block; an outer conductor formed on the side surface and the second end surface of the dielectric block; A plurality of λ / 4 resonators are formed including
The plurality of λ / 4 resonators are arranged along a first side surface and a second side surface forming a pair of the plurality of side surfaces,
A transmission signal input electrode, a reception signal output electrode, and an input / output common electrode are arranged insulated from the outer conductor,
A non-conductive pattern portion extending from the non-conductive region of the first end surface to the second end surface is formed on the first side surface and / or the second side surface, and the non-conductive pattern portion is The λ / 4 resonator is connected to the non-conductive region within a predetermined range with respect to the arrangement direction of the λ / 4 resonator, and the predetermined range is centered on the center of the dielectric block with respect to the arrangement direction of the λ / 4 resonator. In the range of 1/2 times the size of the body block And the non-conductive pattern portion functions as a λ ′ / 4 slot line resonator with respect to the wavelength λ ′ of the lower harmonic of the λ / 4 resonator. A duplexer characterized by that,
Is provided.
[0015]
It is preferable that the non-conductive pattern portion has a length that is ¼ to 1 times the distance between the first end surface and the second end surface. It is preferable that the nonconductive pattern portion has a width equal to or less than 1/4 times the dimension of the dielectric block in the arrangement direction of the λ / 4 resonators. A plurality of the non-conductive pattern portions may be formed.
[0016]
In one aspect of the present invention, the pair of input / output electrodes or the transmission signal input electrode, the reception signal output electrode, and the input / output common electrode are formed on a side surface of the dielectric block.
[0017]
In one aspect of the present invention, the first side surface of the dielectric block is bonded to a mounting board, and the mounting board has a ground conductor pattern connected to an outer conductor on the first side surface and a front surface. An input output electrode or an electrode pattern connected to the transmission signal input electrode, the reception signal output electrode, and the input / output common electrode.
[0018]
Furthermore, according to the present invention, the above object is achieved as follows:
In the duplexer as described above, the transmission signal input electrode and the reception signal output electrode are both one of the input electrode and the output electrode, and the input / output common electrode is the other of the input electrode and the output electrode. A multiplexer characterized by
Is provided.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, specific embodiments of the present invention will be described with reference to the drawings. In the drawings described below, members or portions having equivalent functions are denoted by corresponding reference numerals.
[0020]
1 and 2 are schematic perspective views showing a first embodiment of a dielectric filter according to the present invention. FIG. 3 is an exploded perspective view showing the dielectric filter of the present embodiment bonded to the mounting substrate.
[0021]
In these drawings, reference numeral 2 denotes a rectangular parallelepiped dielectric block. As a material of the block 2, for example, BaTiO _Three Series ceramics can be used. A plurality of vertical through holes 3 having a circular cross section are formed in the block 2 in parallel with each other. A conductor film is attached to the inner surface of the through hole 3, and an inner conductor 4 is formed by the conductor film. In addition, a conductor film is attached to the four side surfaces along the through hole 3 of the dielectric block 2 and one end face (the lower end face in FIG. 1) where the through hole 3 opens, and the outer conductor 5 is provided by the conductor film. Is formed. For example, Ag can be used as the material of the inner conductor 4 and the outer conductor 5. In this way, a required portion of the surface of the dielectric block 2 is metallized to form λ / 4 coaxial dielectric resonators 12A, 12B, and 12C. The end face where the inner conductor 4 and the outer conductor 5 are short-circuited (the lower end face in FIG. 1) is called a short-circuit end face, and the end face where the inner conductor 4 and the outer conductor 5 are not short-circuited (the upper end face in FIG. 1) is opened. Called the end face. On the open end surface, as shown in the figure, a capacitive electrode 4 ′ made of a conductor film connected to each of the inner conductors 4 is formed, but the other regions are not provided with a conductor film and are not conductive. It is an area.
[0022]
That is, in the present embodiment, a dielectric having a paired lower end surface and upper end surface, four side surfaces crossing these end surfaces, and three parallel through holes 3 extending between the lower end surface and the upper end surface. Three λ / 4 resonators 12A and 12B including a block 2; an inner conductor 4 formed on the inner surface of the through hole of the dielectric block 2, and an outer conductor 5 formed on the side surface and the lower end surface of the dielectric block. , 12C are formed. These λ / 4 resonators 12A, 12B, and 12C are arranged along a first side surface A and a second side surface B that form a pair of four side surfaces.
[0023]
In the present embodiment, a three-stage bandpass filter 12 is formed by three resonators 12A, 12B, and 12C arranged in parallel in the same direction. In the present embodiment, all resonators 12A, 12B, and 12C are formed using a single dielectric block 2.
[0024]
In FIG. 1, on the side surface A (mounting surface) of the dielectric block 2, an input electrode 6 and an output electrode made of a conductor film insulated from the outer conductor 5 are provided in the vicinity of the left end resonator 12A and the right end resonator 12C. 7 is formed. The input electrode 6 is capacitively coupled to the resonator 12A, and the output electrode 7 is capacitively coupled to the resonator 12C.
[0025]
As shown in FIG. 2, a non-conductive pattern portion 15 extending from the open end surface toward the short-circuit end surface is formed on the side surface B of the dielectric block 2. No conductor film is formed on the outer peripheral portion of the open end face, and therefore the nonconductive pattern portion 15 extends from the nonconductive region of the open end face toward the short-circuit end face. The non-conductive pattern portion 15 is connected to the non-conductive region of the open end face within a predetermined range with respect to the arrangement direction of the λ / 4 resonators 12A, 12B, 12C, and the predetermined range is related to the arrangement direction of the λ / 4 resonator. Centering on the center WC of the dielectric block 2, the width is in a range that is ½ times the dimension W of the dielectric block 2 (that is, ¼ on each of the left and right sides of WC).
[0026]
The non-conductive pattern portion 15 has a stripe shape having a length L and a width D. The non-conductive pattern portion 15 can be formed by excluding application of the metallization process in a desired region when the outer conductor 5 is formed on the side surface B by the metallization process.
[0027]
When the height of the dielectric block 2 is H and the width (dimension in the arrangement direction of the resonators 12A, 12B, and 12C) is W, the length L of the non-conductive pattern portion 15 is 1/4 to 1 times H. And the width D of the non-conductive pattern portion 15 is preferably ¼ times W or less. As a result, the effect of improving the spurious characteristics becomes significant. Note that the minimum value of D is the minimum value at which DC insulation is performed in the nonconductive pattern portion 15. However, from the viewpoint of not changing the coupling between resonators of the dielectric filter, it is preferable that D is small.
[0028]
As shown in FIG. 3, the dielectric block 2 has a side surface A bonded to a mounting substrate (wiring substrate) 20. The mounting substrate 20 has a ground conductor pattern 22 connected to the outer conductor 5 on the side surface A and electrode patterns 26 and 27 connected to the input / output electrodes 6 and 7, respectively. These joining can be performed by soldering or the like.
[0029]
FIG. 4 shows spurious characteristics of the dielectric filter of the present embodiment. This is a case where H = 5.0 mm, W = 4.7 mm, L = 4.5 mm, D = 0.6 mm, and the non-conductive pattern portion 15 is located on the WC. For comparison, FIG. 4 also shows spurious characteristics that differ from those of the present embodiment only in that the non-conductive pattern portion 15 is not present (that is, the outer conductor 5 is formed on the entire side surface B). Yes. In the embodiment of the present invention having the non-conductive pattern portion 15, an attenuation pole is generated near the spurious peak due to the TE mode, and the attenuation in the double harmonic region 2f is good. On the other hand, it can be seen that the attenuation at 2f is insufficient when there is no non-conductive pattern portion.
[0030]
FIG. 5 shows changes in spurious characteristics when only L is changed in the present embodiment. L ₁ = 4.5mm, L ₂ = 4.0 mm, L _Three = 3.5 mm. It can be seen that the attenuation in the second harmonic region 2f gradually decreases as L decreases.
[0031]
As described above, in the present invention, the non-conductive pattern portion 15 is formed in an appropriate size at an appropriate position, thereby appropriately forming an attenuation pole near the harmonic region, thereby improving spurious characteristics. ing. The reason is considered as follows. That is, the spurious mode having a peak near the low-order harmonic region twice or three times the resonance frequency f of the resonator and having the greatest influence on the filter characteristics is TE. ₁₀₁ Mode. The electric field strength in this mode is maximum at the center of the dielectric block 2, that is, at the position of the WC, and minimum at both ends in the direction of the resonator arrangement, and is maximum at the open end face in the direction of the through hole 3 and short-circuit end face. The minimum. The non-conductive pattern portion 15 is Function of λ ′ / 4 slot line resonator for wavelength λ ′ of low-order harmonic of λ / 4 resonator The electric field strength is the maximum at the open portion and the minimum at the short-circuit portion as in the coaxial resonator. The resonance frequency of the slot line resonator is located relatively close to the spurious peak, whereby the slot line resonator and the spurious mode are coupled to each other in a region where the electric field is strong, and the slot line resonator is spurious. It is considered to function as a trap circuit for suppression.
[0032]
The above can be understood from the measurement results of the spurious characteristics shown in FIGS. These measurements are taken when the dimensions shown in FIG. 2 are H = 5.3 mm, W = 5.0 mm, L = 4.0 mm, and D = 0.3 mm.
[0033]
21 shows the case where the non-conductive pattern portion 15 is located on the WC, FIG. 22 shows the case where the non-conductive pattern portion 15 is located at a position shifted from the WC by W / 8, and FIG. 23 shows the non-conductive pattern portion. This is a case where the pattern unit 15 is located by being shifted from the WC by W / 4. As the deviation of the non-conductive pattern portion 15 from the WC increases, the effect of suppressing spurious due to the attenuation pole gradually decreases. Therefore, the non-conductive pattern portion 15 is preferably at a distance within W / 4 from the WC, more preferably at a distance within W / 8 from the WC, and most preferably on the WC.
[0034]
FIG. 24 shows the case where the conductive films on both sides of the non-conductive pattern portion 15 are short-circuited on the open end face. In this case, the non-conductive pattern portion 15 does not have an open portion. λ '/ 4 slot line resonator Therefore, the attenuation pole is not formed at a desired position. Therefore, there is no spurious suppression effect due to the attenuation pole.
[0035]
6 to 8 are schematic perspective views showing second to fourth embodiments of the dielectric filter according to the present invention, respectively. These embodiments differ from the first embodiment only in the form of the non-conductive pattern portion 15 formed on the side surface B of the dielectric block 2.
[0036]
In the embodiment of FIG. 6, the non-conductive pattern portion 15 has an island-like bulge at the lower end. Thereby, an attenuation pole can be shifted to a low region. The island-like bulge may have a shape other than a square as shown in the figure. In this case, the island-shaped bulge portion may protrude from a predetermined range centering on the WC, but is preferably arranged within the predetermined range.
[0037]
In the embodiment of FIG. 7, the non-conductive pattern portion 15 has a meandering curved shape, not a vertical shape. Also in this case, the lower portion of the non-conductive pattern portion 15 may protrude from a predetermined range centering on the WC, but is preferably arranged within the predetermined range.
[0038]
In the embodiment of FIG. 8, two non-conductive pattern portions 15a and 15b are formed. Three or more non-conductive pattern portions may be formed. By forming a plurality of non-conductive pattern portions in this manner, a plurality of attenuation poles can be generated, and spurious characteristics can be further improved. Each non-conductive pattern portion may be different in length and width, and thereby the attenuation pole position can be controlled independently. It should be noted that each of the plurality of non-conductive pattern portions satisfies the conditions described in the above embodiment.
[0039]
FIG. 9 is a schematic perspective view showing a fifth embodiment of the dielectric filter according to the present invention. This embodiment is different from the first embodiment only in the shape of the capacitor electrode formed on the open end face of the dielectric block 2. That is, in this embodiment, a concave portion is formed on the open end surface of the dielectric block 2 corresponding to each through hole 3, and a capacitive electrode 4 ″ is formed on the bottom surface and the inner wall surface of the concave portion. Thus, the coupling capacity between the resonators and the input / output coupling capacity can be increased.
[0040]
FIG. 17 is an exploded perspective view showing a sixth embodiment of the dielectric filter according to the present invention. In this embodiment, a nonconductive pattern portion 15 ′ is formed on the mounting surface A of the dielectric block 2. On the upper surface of the wiring board 20, a non-conductive portion 28 that is somewhat larger than the non-conductive pattern portion 15 ′ is formed at a position corresponding to the non-conductive pattern portion 15 ′. Also in this embodiment, the same effect as the above-described embodiment can be obtained.
[0041]
Furthermore, in the present invention, the non-conductive pattern portion may be provided on both the mounting surface A of the dielectric block 2 and the side surface paired therewith.
[0042]
18 and 19 are schematic perspective views showing seventh and eighth embodiments of the dielectric filter according to the present invention, respectively, and FIG. 20 shows a ninth embodiment of the dielectric filter according to the present invention. It is a disassembled perspective view. In these embodiments, modifications of the input / output electrodes are particularly shown. Although not shown in these drawings, a non-conductive pattern portion as shown in FIG. 2 and the like is formed on the rear side surface of the dielectric block 2.
[0043]
In the embodiment of FIG. 18, the input electrode 6 and the output electrode 7 both extend from the mounting surface A to other side surfaces that are continuous with the mounting surface.
[0044]
In the embodiment of FIG. 19, a coupling dielectric block 32 is used. In the coupling dielectric block 32, a coupling inner conductor 34 is formed on the inner surface of the through hole corresponding to the resonator inner conductor 4 formed in the through hole 3 of the dielectric block 2. Corresponding members of the coupling inner conductor 34 and the resonator inner conductor 4 are mechanically and electrically connected to each other by a conductive connecting member 38 inserted into the through holes. An input electrode 36 and an output electrode 37 are formed on the side surface of the coupling dielectric block 32.
[0045]
In the embodiment of FIG. 20, the insulating rods 44 and 45 are inserted into the through holes in which the inner conductors 4 of the resonators at both ends are formed, and the insertion holes formed in the insulating rods 44 and 45 are respectively inserted. An input electrode pin 46 and an output electrode pin 47 are inserted.
[0046]
10 and 11 are schematic perspective views showing the first embodiment of the duplexer according to the present invention. In the present embodiment, λ / 4 coaxial dielectric resonators 12A, 12B, 12C, 14A, 14B, and 14C and λ / 4 coaxial dielectric resonator 16 are formed. In this embodiment, the three resonators 12A, 12B, and 12C arranged in parallel in the same direction form a three-stage transmission filter (transmission bandpass filter) 12, and are arranged in parallel in the same direction. The three resonators 14A, 14B, and 14C that are arranged form a three-stage reception side filter (reception bandpass filter) 14 between the transmission side filter 12 and the reception side filter 14, that is, the resonator 12C. A resonator 16 for forming an input / output capacitance is disposed between the resonator 14A and the resonator 14A in the same direction as these.
[0047]
In this embodiment, all resonators 12A, 12B, 12C, 14A, 14B, 14C, and 16 are formed using a single dielectric block 2. In other words, the present embodiment has a configuration in which the dielectric block of the transmission filter 12, the dielectric block of the reception filter 14, and the dielectric block of the second resonator 16 are integrated.
[0048]
In FIG. 10, a transmission signal input electrode 106 made of a conductor film insulated from the outer conductor 5 is formed on the dielectric block side surface A in the vicinity of the resonator 12A at the left end of the transmission filter 12, and the reception side A reception signal output electrode 107 made of a conductor film insulated from the outer conductor 5 is formed in the vicinity of the resonator 14 </ b> C at the right end of the filter 14. Further, on the dielectric block side surface A, an input / output common electrode 108 made of a conductor film insulated from the outer conductor 5 is formed in the vicinity of the resonator 16. On the open surface of the dielectric block 2, a connection conductor 109 made of a conductor film insulated from the outer conductor 5 and connecting the common electrode 108 and the inner conductor 4 of the resonator 16 is formed. The connection conductor 109 also functions as a capacitance electrode, like the capacitance electrode 4 ′ connected to the inner conductors of the resonators 12A to 12C and 14A to 14C.
[0049]
The position, length L, and width D of the non-conductive pattern portion 15 shown in FIG. 11 are in the same relationship with the dimensions H and W of the dielectric block 2 as described with reference to FIG. preferable. As a result, for both the transmission-side filter and the reception-side filter, an attenuation pole can be generated near the TE mode peak, and the spurious characteristics can be improved.
[0050]
FIG. 12 is a schematic perspective view showing a second embodiment of the duplexer according to the present invention. In this embodiment, two non-conductive pattern portions 15a and 15b are formed. Three or more non-conductive pattern portions may be formed. By forming a plurality of non-conductive pattern portions in this manner, a plurality of attenuation poles can be generated, and spurious characteristics can be further improved. Each non-conductive pattern portion may be different in length and width, and thereby the attenuation pole position can be controlled independently. In addition, each non-conductive pattern part may differ in length and width, and this can control an attenuation pole position each independently. It should be noted that each of the plurality of non-conductive pattern portions satisfies the conditions described in the above embodiment.
[0051]
FIG. 13 is a schematic perspective view showing a third embodiment of the duplexer according to the present invention. This embodiment is different from the first embodiment only in the shape of the capacitor electrode and the connection conductor formed on the open end face of the dielectric block 2. That is, in the present embodiment, a concave portion is formed in the open end surface of the dielectric block 2 corresponding to each through hole 3, and the capacitive electrode 4 ″ and the connection conductor 109 ′ are formed on the bottom surface and the inner wall surface of the concave portion. As a result, the inter-resonator coupling capacitance and the input / output coupling capacitance can be increased.
[0052]
In the above embodiment, the inner conductors of all the resonators have the same shape and dimensions. However, in the present invention, the shape and size of each resonator can be appropriately changed as desired. For example, the shape and size of the transmission-side filter and the reception-side filter can be different.
[0053]
The transmission signal input electrode 106 and the reception signal output electrode 107 of the duplexer shown in the above embodiment are both used as one of the input electrode and the output electrode, and the input / output common electrode 108 is used as the input electrode. And as the other of the output electrodes, a two-input one-output multiplexer or a one-input two-output multiplexer according to the present invention can be formed.
[0054]
Also in this multiplexer, the same effect of improving spurious characteristics as in the case of the transmission / reception container is obtained.
[0055]
In the present invention, the number of resonators constituting the filter may be other than three.
[0056]
【The invention's effect】
As described above, according to the present invention, the non-conductive pattern portion extending from the non-conductive region on the open end surface toward the short-circuit end surface is formed on the side surface of the dielectric block in the vicinity of the center portion in the resonator arrangement direction. Thus, a dielectric filter, duplexer, and multiplexer capable of obtaining an excellent spurious characteristic by forming an attenuation pole in the vicinity of the harmonics with a simple configuration and capable of reducing manufacturing costs such as assembly. Is provided.
[Brief description of the drawings]
FIG. 1 is a schematic perspective view showing a dielectric filter according to the present invention.
FIG. 2 is a schematic perspective view showing a dielectric filter according to the present invention.
FIG. 3 is an exploded perspective view showing a dielectric filter bonded to a mounting substrate.
FIG. 4 is a graph showing spurious characteristics of a dielectric filter.
FIG. 5 is a graph showing spurious characteristics of a dielectric filter.
FIG. 6 is a schematic perspective view showing a dielectric filter according to the present invention.
FIG. 7 is a schematic perspective view showing a dielectric filter according to the present invention.
FIG. 8 is a schematic perspective view showing a dielectric filter according to the present invention.
FIG. 9 is a schematic perspective view showing a dielectric filter according to the present invention.
FIG. 10 is a schematic perspective view showing a duplexer according to the present invention.
FIG. 11 is a schematic perspective view showing a duplexer according to the present invention.
FIG. 12 is a schematic perspective view showing a duplexer according to the present invention.
FIG. 13 is a schematic perspective view showing a duplexer according to the present invention.
FIG. 14 is a perspective view of a conventional dielectric filter.
FIG. 15 is an exploded perspective view of a conventional dielectric filter.
16 is an equivalent circuit diagram of the dielectric filter of FIG.
FIG. 17 is an exploded perspective view showing a dielectric filter according to the present invention.
FIG. 18 is a schematic perspective view of a dielectric filter according to the present invention.
FIG. 19 is a schematic perspective view of a dielectric filter according to the present invention.
FIG. 20 is an exploded perspective view showing a dielectric filter according to the present invention.
FIG. 21 is a graph showing spurious characteristics of a dielectric filter.
FIG. 22 is a graph showing spurious characteristics of a dielectric filter.
FIG. 23 is a graph showing spurious characteristics of a dielectric filter.
FIG. 24 is a graph showing spurious characteristics of a dielectric filter.
[Explanation of symbols]
2 Dielectric block
3 Through hole
4 Inner conductor
4 ', 4 "capacitive electrode
5 Outer conductor
6 Input electrodes
7 Output electrode
12 Bandpass filter
12A, 12B, 12C Dielectric Resonator
14 Bandpass filter
14A, 14B, 14C Dielectric Resonator
15, 15 ', 15a, 15b Non-conductive pattern part
16 Dielectric resonator
20 Wiring board
22 Ground conductor pattern
26, 27 electrode pattern
28 Non-conductive part
32 Dielectric block for coupling
34 Inner conductor for coupling
36 Input electrodes
37 Output electrode
38 Conductive connection member
44, 45 Insulating rod
46 Input electrode pin
47 Output electrode pin
106 Transmission signal input electrode
107 Received signal output electrode
108 Input / output common electrode
109 Connection conductor

Claims (13)

A pair of first and second end faces, a plurality of side faces crossing the first and second end faces, and a plurality of parallel ends extending between the first and second end faces A dielectric block having a plurality of through holes; an inner conductor formed on an inner surface of the plurality of through holes of the dielectric block; an outer conductor formed on the side surface and the second end surface of the dielectric block; A plurality of λ / 4 resonators are formed including
The plurality of λ / 4 resonators are arranged along a first side surface and a second side surface forming a pair of the plurality of side surfaces,
A pair of input / output electrodes are arranged insulated from the outer conductor;
A non-conductive pattern portion extending from the non-conductive region of the first end surface to the second end surface is formed on the first side surface and / or the second side surface, and the non-conductive pattern portion is The λ / 4 resonator is connected to the non-conductive region within a predetermined range with respect to the arrangement direction of the λ / 4 resonator, and the predetermined range is centered on the center of the dielectric block with respect to the arrangement direction of the λ / 4 resonator. The non-conductive pattern portion functions as a λ ′ / 4 slot line resonator with respect to a wavelength λ ′ of a low-order harmonic of the λ / 4 resonator. A dielectric filter. 2. The dielectric filter according to claim 1, wherein the non-conductive pattern unit has a length that is ¼ to 1 times a distance between the first end surface and the second end surface. . 3. The non-conductive pattern part according to claim 1, wherein the non-conductive pattern part has a width equal to or less than ¼ times a dimension of the dielectric block in the arrangement direction of the λ / 4 resonators. Dielectric filter. The dielectric filter according to claim 1, wherein a plurality of the non-conductive pattern portions are formed. The dielectric filter according to claim 1, wherein the pair of input / output electrodes are formed on a side surface of the dielectric block. The dielectric block has the first side surface bonded to a mounting substrate, and the mounting substrate is connected to an outer conductor on the first side surface and an electrode pattern connected to the input / output electrode. The dielectric filter according to claim 1, wherein A pair of first and second end faces, a plurality of side faces crossing the first and second end faces, and a plurality of parallel ends extending between the first and second end faces A dielectric block having a plurality of through holes; an inner conductor formed on an inner surface of the plurality of through holes of the dielectric block; an outer conductor formed on the side surface and the second end surface of the dielectric block; A plurality of λ / 4 resonators are formed including
The plurality of λ / 4 resonators are arranged along a first side surface and a second side surface forming a pair of the plurality of side surfaces,
A transmission signal input electrode, a reception signal output electrode, and an input / output common electrode are arranged insulated from the outer conductor,
A non-conductive pattern portion extending from the non-conductive region of the first end surface to the second end surface is formed on the first side surface and / or the second side surface, and the non-conductive pattern portion is The λ / 4 resonator is connected to the non-conductive region within a predetermined range with respect to the arrangement direction of the λ / 4 resonator, and the predetermined range is centered on the center of the dielectric block with respect to the arrangement direction of the λ / 4 resonator. The non-conductive pattern portion functions as a λ ′ / 4 slot line resonator with respect to a wavelength λ ′ of a low-order harmonic of the λ / 4 resonator. A duplexer. The duplexer according to claim 7, wherein the non-conductive pattern part has a length that is 1/4 to 1 times a distance between the first end face and the second end face. . 9. The non-conductive pattern part according to claim 7, wherein the non-conductive pattern part has a width equal to or less than ¼ times the dimension of the dielectric block in the arrangement direction of the λ / 4 resonators. A duplexer. The duplexer according to any one of claims 7 to 9, wherein a plurality of the non-conductive pattern portions are formed. The duplexer according to any one of claims 7 to 10, wherein the transmission signal input electrode, the reception signal output electrode, and the input / output common electrode are formed on a side surface of the dielectric block. The dielectric block has the first side surface bonded to a mounting substrate, and the mounting substrate is connected to an outer conductor on the first side surface, the transmission signal input electrode, and the reception signal output electrode. And an electrode pattern connected to each of the input / output common electrodes, the duplexer according to any one of claims 7 to 11. The transmission signal input electrode and the reception signal output electrode of the duplexer according to any one of claims 7 to 12 are both formed as one of an input electrode and an output electrode, and the input / output common electrode is an input electrode and an output. A multiplexer characterized by being the other of the electrodes.

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