JP2005277962A - Dielectric filter, dielectric duplexer, and communication equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a dielectric filter, a dielectric duplexer, and communication equipment having the same, in which a characteristic fluctuation is hard to be produced even a grounded conductor such as a shield case or peripheral components are disposed in the vicinity when mounted on a mounting substrate. <P>SOLUTION: Recesses 9a, 9d are disposed in the vicinity of the short end areas of external coupling holes 3tx, 3ant, 3rx on a first end surface S1 of a dielectric block 1, and the open ends of a resonant holes 2a, 2i. An open surface of each resonant hole 2a-2i is formed by deleting an external conductor 6 in a portion excluding the recesses disposed on the first end surface S1 of the dielectric block 1. With this, the open end areas of the resonant holes 2a, 2i at the end portion of the dielectric block 1 are restricted by the recesses 9a, 9d, so as to stabilize an attenuation pole frequency by a trap resonator, making with high accuracy. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a dielectric filter, a dielectric duplexer adapted to a high frequency circuit, and a communication device including them.

  Patent Document 1 discloses a dielectric filter in which a plurality of resonator holes are provided in a dielectric block.

FIG. 9 is a perspective view of the dielectric duplexer disclosed in Patent Document 1. In FIG. This dielectric duplexer includes a substantially rectangular parallelepiped dielectric block 1, and a transmission filter is configured by a bandpass filter formed by a two-stage resonator of resonator holes 2b and 2c and a trap resonator formed by the resonator hole 2a. A reception filter is composed of a bandpass filter formed by a three-stage resonator of the resonator holes 2d to 2f and a trap resonator formed by the resonator hole 2g. In the first end face 1a of the dielectric block 1, recesses 8 are formed between the resonator holes 2a-2b, between the resonator holes 2c-2d, and 2f-2g, respectively, and the external coupling holes 3a are formed in the regions of the respective recesses 8. , 3b, 3c and external coupling adjusting holes 4a, 4b, 4c are formed respectively.
JP 2000-201002 A

  However, as shown in FIG. 9, in a dielectric filter or a dielectric duplexer in which a plurality of resonator holes are formed in a substantially rectangular parallelepiped dielectric block and the end face of the dielectric block is an open surface, the dielectric There has been a problem that characteristic fluctuations occur when a conductor such as a metal approaches the open side of the block, and electromagnetic waves leak from a dielectric filter or a dielectric duplexer. For example, when mounted on a substrate of a mobile phone terminal, a large number of electronic components are mounted in a limited space, and are easily affected by peripheral components such as a shield case covering a high-frequency component, a VCO, and a SAW filter. .

  In particular, among the plurality of resonator holes provided in the substantially rectangular parallelepiped-shaped dielectric block, the resonator hole provided in the vicinity of the end of the dielectric block is easily affected by surrounding components and members. Further, in a dielectric filter or a dielectric duplexer provided with a trap resonator as shown in FIG. 9 in order to secure an attenuation amount in a predetermined band, when a conductor such as a shield case is close to the trap resonator, Capacitance with the conductor is generated, the resonance frequency of the trap resonator decreases, the attenuation pole frequency of the dielectric filter or dielectric duplexer fluctuates, and there is a problem that the attenuation characteristics of the filter are greatly affected. . Similarly, for the resonator constituting the bandpass filter section, the filter characteristics change when a capacitance is generated between the conductor and the conductor, but the problem as in the trap resonator does not occur. That is, generally, there is a margin in the characteristics of the pass band, so that a fatal fluctuation such as the trap resonator that determines the characteristics of the stop frequency part from the high band or the low band of the pass band to the cutoff band does not occur.

  For example, even if the passband according to the standard is 30 MHz, for example, the passband as a filter is designed with a wider bandwidth, for example, 40 MHz, so that a slight variation in the center frequency fo of the passband is allowed. On the other hand, if the trap resonator fluctuates by 1 MHz, the amount of attenuation at the frequency at which the necessary amount of attenuation is obtained varies greatly. Similarly, even if the resonator of the band-pass filter section fluctuates by 1 MHz, the characteristics of the entire pass band are hardly affected.

  Moreover, since the above-mentioned problems occur after mounting the dielectric filter or dielectric duplexer on the mounting board, the design is not limited to designing the dielectric filter or dielectric duplexer as a single component, but also the mounting structure and mounting method on the board. Need to be considered.

  Accordingly, an object of the present invention is to eliminate the above-mentioned problems, for example, when a conductor such as a shield case and peripheral parts are close to each other when mounted on a mounting board, characteristic fluctuation hardly occurs, and a predetermined filter characteristic is highly accurate. It is an object of the present invention to provide a dielectric filter, a dielectric duplexer, and a communication device including them.

  (1) A dielectric filter of the present invention includes a plurality of resonator holes penetrating between both end surfaces inside a dielectric block having a side surface continuous between a first end surface and a second end surface that are in a substantially parallel relationship, and At least one external coupling hole is provided, an inner conductor is formed on the inner peripheral surface of each resonator hole and the outer coupling hole, an outer conductor is formed on the outer surface of the dielectric block, and the outer coupling of the first end surface of the dielectric block A recess is provided in the vicinity of the short-circuited end region of the hole and the open end of the predetermined resonator hole, the outer conductor other than the recess of the first end face is deleted, and the open face of each resonator hole is formed on the first end face, The open end region of the resonator hole provided with the concave portion in the vicinity thereof is limited by the concave portion.

  (2) In the dielectric filter according to the present invention, in (1), the resonator hole provided with the concave portion in the vicinity thereof is located near the side surface that appears as a short side on the first end surface and the second end surface of the side surface of the dielectric block. The provided resonator hole.

  (3) In the dielectric filter according to the present invention, in (1) and (2), a band-pass filter unit is configured by a resonator including several resonator holes among the plurality of resonator holes, and the concave portion is disposed in the vicinity. A trap resonator in which an attenuation pole is provided at a high frequency side or low frequency side stop frequency in the pass band of the band pass filter section or a frequency in the vicinity thereof is configured by the resonator hole provided with the above.

  (4) The dielectric duplexer according to the present invention is characterized in that at least one filter section of the plurality of filter sections included in the dielectric block is the dielectric filter according to any one of claims 1 to 3.

  (5) The communication device according to the present invention is characterized in that the dielectric filter according to (1) to (3) or the dielectric duplexer according to (4) is provided in the high frequency circuit section.

  (1) A recess is provided in the vicinity of the short-circuited end region of the external coupling hole on the first end face of the dielectric block and the open end of the predetermined resonator hole, and each outer resonance other than the recess is removed to remove each resonance on the first end face. The open surface of the resonator hole is formed, and the open end region of the resonator hole having a recess in the vicinity thereof is limited. Therefore, since the open end region of the resonator hole in which the recess is provided in the vicinity is limited over the entire structure of the end face of the dielectric block, the open end region of the resonator hole is limited. Even when a conductor such as a shield cover or other parts are close to each other in the mounted state, it is less affected by them, and leakage of electromagnetic waves can be suppressed. Further, by removing the outer conductor formed on the end face of the dielectric block, the shape and dimension of the open end region of the resonator can be set with higher accuracy than in the structure in which the open face of the resonator hole is formed. For example, by simply setting the position and dimensions of the recess without changing the shape of the entire dielectric block, the characteristics of the resonator provided with the recess can be determined with high accuracy.

  (2) By providing the recesses on the side surfaces appearing as short sides on the first end surface and the second end surface of the dielectric block, the dielectric filter is mounted on the substrate and can be used over a wide range with a shield case and other components. It is possible to effectively stabilize the characteristics of resonators that are close to each other.

  (3) A trap resonator is formed by a resonator hole provided with the concave portion in the vicinity, and an attenuation pole is provided in the vicinity of the stop frequency on the high band side or low band side of the pass band of the band pass filter with the trap resonator. By configuring as described above, it is possible to stabilize the attenuation pole frequency that is most easily affected, and to stabilize the entire filter characteristics.

  (4) Further, according to the present invention, by configuring a dielectric duplexer provided with a single dielectric block using the dielectric filter of any one of (1) to (3) as a filter unit, for example, antenna sharing It will be used as a container.

  (5) Further, according to the present invention, a small communication device having excellent high frequency circuit characteristics can be obtained by providing the dielectric filter or the dielectric duplexer in the high frequency circuit section.

The configuration of the dielectric duplexer according to the first embodiment will be described with reference to FIGS.
FIG. 1 is an external perspective view of a dielectric duplexer. However, in order to show the formation positions of the input / output electrodes, which will be described later, the upper and lower surfaces are shown upside down, as opposed to the mounting state on the substrate. FIG. 2 is a three-side view of the dielectric duplexer, where FIG. 2A is a front view seen from the open side, FIG. 2B is a bottom view, and FIG. 2C is a right side view.

  The left front surface of the dielectric block 1 in FIG. 1 is the first end surface S1, and the right rear surface facing it is the second end surface S2. The dielectric block 1 has a substantially rectangular parallelepiped shape having four continuous side surfaces between the first end surface S1 and the second end surface S2. The dielectric block 1 includes a plurality of resonator holes 2a to 2i, outer coupling holes 3tx, 3ant, 3rx and outer coupling adjustment holes 4tx, 4ant, 4rx, each having an inner conductor 5 formed on each inner surface, It is provided so as to penetrate between both end faces of the end face S1 and the second end face S2. As shown in FIG. 2A, the resonator holes 2a to 2i have a step shape in which the inner diameter on the open end side is wider than the inner diameter on the short-circuit end side.

  The first end face S1 of the dielectric block 1 is provided with a recess 8a in a portion serving as a short-circuit end region of the external coupling hole 3tx and the external coupling adjustment hole 4tx. Further, a recess 8b is provided in a portion that becomes a short-circuit end region of the external coupling hole 3ant and the external coupling adjustment hole 4ant. Similarly, a recess 8c is provided in a portion that becomes a short-circuited end region of the external coupling hole 3rx and the external coupling adjustment hole 4rx. However, since the depths of the recesses 8a, 8b, and 8c are shallow in this example, the recesses 8a, 8b, and 8c appear to be substantially flush with the open surfaces of the resonator holes 2a to 2i in FIG. .

  The first end face S1 of the dielectric block 1 is provided with a recess 9a that is recessed by a predetermined depth from the first end face S1 in the vicinity of the open end of the resonator hole 2a. Similarly, a recess 9d that is recessed from the first end face S1 by a predetermined depth is provided in the vicinity of the open end of the resonator hole 2i. Further, a recess 9b is provided in the vicinity of the open ends of the resonator holes 2b, 2c, and 2d, and a recess 9c is provided in the vicinity of the resonator holes 2f, 2g, and 2h.

  An outer conductor 6 is formed on the outer surface of the dielectric block 1. However, the first end face S1 of the dielectric block 1 is formed by removing the outer conductor 6 once formed by grinding or polishing and removing the outer conductors of the openings of the resonator holes 2a to 2i, thereby opening the openings. Is the open end of the resonator hole. During the grinding or polishing, the outer conductor 6 on the inner surfaces of the recesses 8a to 8c and 9a to 9d remains without being deleted.

  From the second end surface S2 of the dielectric block 1 to the upper surface in FIG. 1, three input / output electrodes 7tx, 7ant, 7rx are formed which are respectively connected to the inner conductors formed on the inner surfaces of the external coupling holes 3tx, 3ant, 3rx. . These input / output electrodes 7tx, 7ant, 7rx are separated from the outer conductor 6.

  Resonator holes 2a to 2i each act as a quarter wavelength resonator with one end open and the other end short-circuited. Since the outer conductor 6 is formed on the inner surface of the recess 9b, a predetermined stray capacitance is generated between the vicinity of the open ends of the resonator holes 2b, 2c, and 2d and the outer conductor of the recess 9b. Thereby, the three resonators by the resonator holes 2b, 2c and 2d are inductively coupled in order. The resonator formed by the resonator hole 2b and the line formed by the external coupling hole 3tx are coupled in an interdigital manner. Similarly, the resonator formed by the resonator hole 2d and the line formed by the external coupling hole 3ant are coupled in an interdigital manner. The three resonators by the resonator holes 2b, 2c, and 2d function as a filter having a passband characteristic having an attenuation pole on the high frequency side of the passband.

  The resonator formed by the resonator hole 2a acts as a trap resonator by interdigitally coupling with the external coupling hole 3tx alone. The resonance frequency of this trap resonator is set to the high-side stop frequency of the pass band or a frequency in the vicinity thereof. Thus, a transmission filter unit having a band pass characteristic having a steep attenuation characteristic from the pass band to the high frequency side attenuation band between the input / output electrodes 7tx-7ant is configured.

  On the other hand, the two resonators by the resonator holes 2e and 2f are capacitively coupled. The two resonators by the resonator holes 2f and 2g are inductively coupled by the presence of the recess 9c in the vicinity of their open ends. Further, the two resonators by the resonator holes 2g and 2h are capacitively coupled. The resonator formed by the resonator hole 2e is interdigitally coupled to the line formed by the external coupling hole 3ant. Similarly, the resonator formed by the resonator hole 2h and the line formed by the external coupling hole 3rx are coupled in an interdigital manner. As described above, the four resonators formed by the resonator holes 2e to 2h act as filters that exhibit bandpass filter characteristics having attenuation poles on the low-pass side and the high-pass side of the passband by inductive coupling and capacitive coupling, respectively. To do.

  The resonator by the resonator hole 2i acts as a trap resonator by interdigitally coupling with the external coupling hole 3rx alone. The resonance frequency of this trap resonator is set to the lower stop frequency of the pass band or a frequency in the vicinity thereof. Thus, a reception filter unit having a band pass characteristic having a steep attenuation characteristic from the pass band to the low-frequency side attenuation band between the input / output electrodes 7rx-7ant is configured.

  As described above, since the recesses 9a and 9d having the outer conductor 6 formed on the inner surfaces of the recesses 9a and 9d are provided in the vicinity of the open ends of the resonator holes 2a and 2i, the open ends of the resonator holes 2a and 2i are provided. Even if a ground conductor such as a shield cover or other parts are close to each other in a state where the area is mounted on the board, the area is limited, and it is difficult to be influenced by them, and leakage of electromagnetic waves can be suppressed.

  Furthermore, by removing the outer conductor formed on the end face of the dielectric block, the shape dimension of the open end region of the resonator can be set with higher accuracy than in a structure in which the open face of the resonator hole is formed. For example, the characteristics of the trap resonator by the resonator holes 2a and 2i can be determined with high accuracy only by setting the positions and dimensions of the recesses 9a and 9d without changing the shape of the entire dielectric block.

  In addition, by disposing the external coupling adjustment hole 4tx whose both ends are short-circuited to the outer conductor 6 between the resonator holes 2a-2b, unnecessary coupling between the two resonators by both resonator holes can be prevented. The amount of external coupling with the trap resonator by the resonator hole 2a and the amount of external coupling with the resonator by the resonator hole 2b can be determined by the positional relationship with the external coupling hole 3tx. Similarly, by disposing the external coupling adjusting hole 4rx whose both ends are short-circuited to the outer conductor 6 between the resonator holes 2h-2i, unnecessary coupling between the two resonators by both resonator holes can be prevented. Further, the amount of external coupling between the resonator hole 2i and the trap resonator and the amount of external coupling between the resonator hole 2h and the resonator can be determined by the positional relationship with the external coupling hole 3rx. Similarly, by disposing the external coupling adjusting hole 4ant between the resonator holes 2d-2e, unnecessary coupling between the two resonators by both resonator holes can be prevented. Further, the amount of external coupling with the resonator by the resonator hole 2d and the amount of external coupling with the resonator by the resonator hole 2e can be determined by the positional relationship with the external coupling hole 3ant.

The manufacturing method of this dielectric duplexer is as follows.
(1) First, a dielectric block 1 provided with a plurality of resonator holes 2a to 2i, external coupling holes 3tx, 3ant, 3rx, external coupling adjustment holes 4tx, 4ant, 4rx, and recesses 9a-9d is made of a dielectric ceramic. Formed by molding.

  (2) Next, a conductor film is formed on the entire inner surface of each hole of the dielectric block 1 and the entire outer surface including the recesses of the dielectric block 1.

  (3) The first end surface S1 of the dielectric block 1 is ground or polished by a predetermined thickness to remove the conductor films on the surfaces other than the recesses 8a to 8c and 9a to 9d, thereby forming an open surface.

  (4) The input / output electrodes 7tx, 7ant, and 7rx are formed with a portion of the conductor film by grinding a predetermined amount of the periphery of the portions that become the input / output electrodes 7tx, 7ant, and 7rx using an ultrasonic grinding tool.

  FIG. 3 shows filter characteristics of the transmission filter unit and the reception filter unit. (A) shows the transmission characteristic S21 of the transmission filter unit, and the reflection characteristic viewed from the input / output electrode 7tx, which is the transmission signal input terminal, for S11. Here, fta and ftb are two attenuation poles generated by inductive coupling of the three resonators by the resonator holes 2b, 2c and 2d shown in FIG. Further, ftt is an attenuation pole due to the trap resonator of the resonator hole 2a.

  In this way, by generating the attenuation pole ftt by the trap resonator at or near the high band side stop frequency of the pass band, the attenuation characteristic from the pass band to the high band side attenuation band can be sharpened.

  FIG. 3B shows the transmission characteristic S21 of the reception filter unit and the reflection characteristic S11 viewed from the input / output electrode 7ant that is the antenna terminal. Here, fra, frb, and frc are attenuation poles due to capacitive coupling and inductive coupling of the four resonators by the resonator holes 2e, 2f, 2g, and 2h shown in FIG. Further, frt is an attenuation pole due to the trap resonator of the resonator hole 2i.

  In this way, by generating the attenuation pole frt by the trap resonator at or near the low-band stop frequency of the pass band, the attenuation characteristic from the pass band to the low-band attenuation band can be sharpened.

Next, the results obtained for the characteristic stability with respect to the conductor approach to the dielectric duplexer will be shown.
FIG. 4 shows the configuration of the stability measuring apparatus. In order to bring the grounded conductor (metal unit) 202 close to a position away from the open surface (first end surface) of the dielectric duplexer 100 as a sample, the spacer fixing part 200 and the spacer 201 are connected to the dielectric duplexer 100. A characteristic change was obtained depending on whether the conductor 202 was placed or not placed at a predetermined position with respect to the attachment position.

  Here, the dimensions of each part of the dielectric duplexer 100 are as shown in FIG. The numerical dimension in the figure is [mm]. FIG. 5 shows the difference in characteristics between the case where the recess 9d shown in FIG. 1 is provided and the case where the recess 9d is not provided. In (A), the horizontal axis is the distance between the open surface of the dielectric duplexer 100 and the conductor 202, and the vertical axis is the frequency of the attenuation pole by the trap resonator for the reception filter section. FIG. 5B shows insertion loss, ripple, reflection loss at a frequency of 1930 to 1990 MHz, and attenuation at 1910 MHz when the distance between the open surface and the conductor is 1 mm.

  In this way, due to the approach of the conductor to the open surface, the frequency variation is suppressed to be small when the concave portion 9d is present compared to the case where the concave portion 9d is not present. Further, it is possible to suppress deterioration of any of insertion loss, ripple, reflection loss, and attenuation when the conductor is close to the open surface.

  FIG. 6 shows the difference in characteristics depending on the presence / absence of the recess 9d in the pass characteristics of the reception filter section. (A) and (B) are characteristics when the concave portion 9d is provided, and (B) is an enlarged view of a portion C in (A). Moreover, (C) is a characteristic when the concave portion 9d is not provided, and (D) is an enlarged view of a C portion in (C). When the concave portion 9d is not provided, the attenuation greatly deteriorates from p2 to p2 ′ at a frequency near the attenuation pole by the trap resonator, whereas when the concave portion 9d is provided, the attenuation decreases from p1 to p1 ′. Only. In this way, fluctuations in attenuation at frequencies near the attenuation pole due to the trap resonator can be suppressed to a small level.

Next, a dielectric duplexer according to a second embodiment will be described with reference to FIG.
FIG. 7 is an external perspective view of two dielectric duplexers having different configurations. In the example shown in (A), the shapes of the recesses 9a and 9d provided in the vicinity of the open ends of the resonator holes 2a and 2i are different from those shown in FIG. In the example shown in FIG. 1, the recesses 9a and 9d are stepped by a predetermined depth from the first end face S1 of the dielectric block. However, in the example shown in FIG. The edge formed by the side surfaces (upper and lower surfaces in the figure) appearing as long sides on the first end surface S1 and the second end surface S2 and the first end surface S1 of the dielectric block 1 is chamfered.

  In the example shown in FIG. 7B, similarly to the recesses 8a, 8b, and 8c provided in the short-circuit end region of the external coupling hole, a recess that is recessed by a predetermined depth from the first end surface S1 toward the second end surface S2. 9a and 9d are formed. Even if it is such a shape, the same effect is acquired. However, in the example of (A), since the shapes of the open end regions of the resonator holes 2a and 2i change depending on the grinding amount of the first end face S1 of the dielectric block 1, two trap resonators by the resonator holes 2a and 2i are used. The amount of grinding may be controlled so that the resonance frequency of this becomes a predetermined frequency.

  In the first and second embodiments, the dielectric duplexer is configured as an antenna duplexer in which the transmission filter unit and the reception filter unit are provided in a single dielectric block. However, the input / output electrodes are provided. The same applies to a single filter.

  Next, a configuration example of a communication apparatus according to the third embodiment will be described with reference to FIG. In FIG. 8, ANT is a transmission / reception antenna, DPX is a duplexer, BPFa and BPFb are band pass filters, AMPa and AMPb are amplifier circuits, MIXa and MIXb are mixers, OSC is an oscillator, and SYN is a frequency synthesizer.

  MIXa mixes the transmission intermediate frequency signal IF and the signal output from SYN, BPFa passes only the transmission frequency band of the mixed output signal from MIXa, and AMpa amplifies the power and ANTs it through DPX. Send more. AMPb amplifies the received signal extracted from DPX. BPFb passes only the reception frequency band of the reception signal output from AMPb. MIXb mixes the frequency signal output from SYN and the received signal, and outputs a received intermediate frequency signal IF.

  The duplexer according to the first and second embodiments is used for the duplexer DPX portion shown in FIG. In addition, as the band pass filters BPFa and BPFb, a dielectric filter having a structure of one filter portion of the duplexers according to the first and second embodiments is used.

1 is an external perspective view of a dielectric duplexer according to a first embodiment. Three-sided view of the same dielectric duplexer The figure which shows the frequency characteristic of the transmission filter part of the same dielectric duplexer, and a reception filter part The figure which shows the characteristic stability measurement state to the conductor approach of the same dielectric duplexer The figure which shows the difference of the characteristic stability with respect to the conductor approach by the presence or absence of a recess The figure which shows the difference of the characteristic stability with respect to the conductor approach by the presence or absence of a recess A perspective view showing an example of composition of two dielectric duplexers concerning a 2nd embodiment. The block diagram which shows the structure of the communication apparatus which concerns on 3rd Embodiment. The figure which shows the structure of the conventional dielectric duplexer

Explanation of symbols

1-dielectric block 2-resonator hole 3-outer coupling hole 4-outer coupling adjustment hole 5-inner conductor 6-outer conductor 7-input / output electrode 8,9-recess S1-first end face S2-second end face 100 -Dielectric duplexer 200-Spacer fixing part 201-Spacer 202-Conductor

Claims (5)

A plurality of resonator holes and at least one external coupling hole penetrating between both end surfaces are provided in a dielectric block having a side surface continuous between a first end surface and a second end surface that are in a substantially parallel relationship, and each resonance In the dielectric filter in which the inner conductor is formed on the inner peripheral surface of the device hole and the outer coupling hole, and the outer conductor is formed on the outer surface of the dielectric block,
A recess is provided in the vicinity of the short-circuited end region of the external coupling hole on the first end face of the dielectric block and the open end of the predetermined resonator hole, and the outer conductor other than the recess on the first end face is deleted, and the first end face A dielectric filter, wherein an open surface of each resonator hole is formed, and an open end region of the resonator hole provided with the recess in the vicinity thereof is limited by the recess.   2. The dielectric hole according to claim 1, wherein the resonator hole provided with the concave portion in the vicinity thereof is a resonator hole provided in a vicinity of a side surface that appears as a short side on the first end surface and the second end surface among the side surfaces of the dielectric block. Body filter.   A bandpass filter unit is configured by a resonator including several resonator holes among the plurality of resonator holes, and a high frequency band of the bandpass filter unit is formed by a resonator hole provided with the recess in the vicinity thereof. The dielectric filter according to claim 1, wherein a trap resonator is provided in which an attenuation pole is provided at a stop frequency on the side or low band side or a frequency in the vicinity thereof.   The dielectric duplexer which is a dielectric filter in any one of Claims 1-3 in which several filter parts are comprised in the dielectric material block, and at least 1 filter part is the dielectric filter in any one of Claims 1-3.   A communication apparatus comprising the dielectric filter according to claim 1 or the dielectric duplexer according to claim 4 in a high-frequency circuit unit.

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