JP3953447B2 - Dielectric duplexer - Google Patents

Description

  The present invention relates to a dielectric duplexer that is installed in a communication device such as a mobile communication device and determines a pass characteristic of a transmission signal and a reception signal in a frequency band.

  Conventionally, a mobile communication device that transmits and receives signals in a frequency band of several hundred MHz to several GHz, as shown in FIG. 14, is connected to an antenna (7) via a dielectric duplexer (9) and a transmission circuit (71) and reception. The circuit (72) is connected, and the antenna (7) is shared by the transmitting circuit (71) and the receiving circuit (72) by the equipment of the dielectric duplexer (9) (patent) Reference 1).

As shown in FIG. 9, the conventional dielectric duplexer (9) includes a single dielectric block (91) made of ceramics, and the dielectric block (91) includes a plurality of through holes (96) ( 97) (98) was established, and a conductive layer (92) made of silver was formed on the front surface, back surface, both side surfaces, the back surface of the dielectric block (91) and the inner peripheral surface of the through hole. . Also, the antenna layer (93) to which the antenna is to be connected, the transmission terminal (94) to which the transmission circuit is to be connected, and the reception circuit to which the reception circuit is to be connected are partly formed by the conductor layer (92) Terminal (95) is formed (see Patent Document 2).
In the dielectric duplexer (9), a resonator filter for transmission is formed between the antenna terminal (93) and the transmission terminal (94), and the antenna terminal (93) and the reception terminal ( A resonator filter for reception is configured during 95).

  In addition, as the above-mentioned monoblock type dielectric duplexer, there is proposed a through-hole for adjusting the coupling strength between the resonators between the resonators constituting each resonator filter. (See Patent Document 3).

In the monoblock type dielectric duplexer (9) shown in FIG. 9, the front surface of the dielectric block (91) is an open surface (90) from which the conductor layer is removed, and the back surface of the dielectric block (91). Is a short-circuit surface (99) covered with a conductor layer, and open surfaces of a plurality of resonators constituting the resonator filter are oriented in the same direction. In the manufacturing process of the dielectric duplexer (9), the open surface (90) can be formed by removing the conductive layer formed on the front surface of the dielectric block (91) by polishing.
On the other hand, although it is possible to produce a dielectric duplexer in which the directions of the open surface and the short-circuit surface of a plurality of resonators constituting the dielectric duplexer are interchanged (see FIG. 7 of Patent Document 3), In this case, it is necessary to provide a level difference between the front and back surfaces of the dielectric block (91) to enable the polishing process.

JP-A-9-83214 US Pat. No. 5,250,916 US Pat. No. 5,994,978

  In the conventional monoblock type dielectric duplexer, it was relatively easy to adjust the frequency characteristics of the passband, but there was a problem that a sufficient attenuation effect could not be obtained for the high frequency range component. . For example, FIGS. 11A and 11B show the frequency characteristics of the received signal and the transmitted signal, respectively, and a large spurious mode S is generated in the vicinity of 4 GHz as shown.

  In addition, in the dielectric duplexer (Patent Document 3) in which through holes for adjusting the coupling between the resonators are opened, the coupling strength by the through holes can be adjusted to some extent, but the effect is not good. In addition to being sufficient, there is a problem that a signal transmitted from the transmission circuit flows into the reception circuit through the dielectric duplexer. For example, FIG. 13 shows the result of measuring the isolation characteristics between the transmission terminal and the reception terminal of a conventional monoblock type dielectric duplexer. As shown in the figure, the transmission band Tx is 50.0 dB. In the band Rx, only 40.8 dB of attenuation is obtained.

  Accordingly, an object of the present invention is to provide a dielectric duplexer that can sufficiently attenuate high frequency band components and has good isolation characteristics.

  A dielectric duplexer according to the present invention includes an antenna terminal to which an antenna is to be connected, a transmission terminal to which a transmission circuit is to be connected, and a reception terminal to which a reception circuit is to be connected. In the dielectric duplexer in which a transmission resonator filter is configured between the antenna terminal and the transmission terminal, and a reception resonator filter is configured between the antenna terminal and the reception terminal, the antenna terminal A first coaxial dielectric resonator provided with a through hole functioning as a part of a resonator filter for transmission and a through hole functioning as a part of a resonator filter for reception; A terminal, a second coaxial dielectric resonator provided with a through-hole functioning as a part of the transmission resonator filter, the reception terminal, and a part of the reception resonator filter Each of the coaxial dielectric resonators includes a through hole formed in the dielectric block, a front surface, a back surface, both side surfaces of the dielectric block, The two resonator filters for transmission and reception each have a coaxial dielectric resonator juxtaposed to each other, and a conductor layer formed on a back surface and an inner peripheral surface of the through hole. Each of the two resonator filters for trust and reception has a joint part joined between the side surfaces of two adjacent coaxial dielectric resonators, and a conductor layer is provided between the dielectric blocks in the joint part. An intervening resonator shield part and a resonator coupling part formed by removing a conductor layer between the dielectric blocks are provided.

In the above-described dielectric duplexer of the present invention, the resonator shield part in which the conductor layer is interposed between the dielectric blocks of two adjacent coaxial dielectric resonators, and the resonator in which the conductor layer is not interposed between the dielectric blocks. Since the coupling portion is provided, the coupling strength of the resonator can be adjusted by adjusting the ratio of the sizes of the resonator shield portion and the resonator coupling portion.
Here, the resonator shield portion provided between the dielectric blocks of the two coaxial dielectric resonators constituting the resonator filter is formed by a conductor layer interposed between the two blocks. Sufficient shielding effect is demonstrated. Also, since the conductor layers covering the front and back surfaces of the dielectric duplexer are connected to each other by a conductor layer interposed between the coaxial dielectric resonators, the conductor layers on the front and back surfaces of the dielectric duplexer are connected to each other. The generated potential difference becomes extremely small, and the effect of grounding on the conductor layer is increased. As a result, a frequency characteristic in which the high frequency region component is sufficiently suppressed is realized.

  Further, since the conductor layer interposed between the dielectric blocks is also interposed between the dielectric filter for transmission and the dielectric filter for reception, both dielectric filters can be obtained by the shielding effect exhibited by the conductor layer. The coupling | bonding between is suppressed and an isolation characteristic is improved.

In a specific configuration, the two side surfaces of the two coaxial dielectric resonators to be joined to each other have a depth greater than the thickness of the conductor layer and extend from the front surface to the back surface of the coaxial dielectric resonator. A groove is recessed to form the resonator coupling portion.
According to the specific configuration, after forming the conductor layers on the side surfaces of the two dielectric blocks to be joined in the manufacturing process of the dielectric duplexer, the conductor layers have a thickness equal to or greater than the thickness. By performing the groove processing having a depth, the resonator layer can be formed by cutting the conductor layer.
The groove is a groove formed in the center of the joint surface away from the front surface and the back surface of the coaxial dielectric resonator, or a groove that is opened and / or opened on either the front surface or the back surface of the coaxial dielectric resonator. The provided groove can be adopted.

  Further, in the dielectric duplexer according to the present invention, the two resonator filters for transmission and reception each have a joint portion joined between side surfaces of two adjacent coaxial dielectric resonators, The joint is provided with a groove that opens in either or both of the front and back surfaces of both coaxial dielectric resonators, and a resonator shield portion comprising a conductor layer covering the groove, and both coaxial dielectric resonances. And a resonator coupling portion formed by removing a conductor layer between the dielectric blocks of the resonator.

Further, in a specific configuration, each of the plurality of coaxial dielectric resonators has an open surface on which a conductor layer is not formed on the front surface of the dielectric in which one end of the through hole opens, and the other through holes. It has a short-circuited surface with a conductor layer on the back side of the dielectric block that opens at the end, and the open surfaces of all coaxial dielectric resonators face in the same direction, or the directions of the open surface and the short-circuited surface Are alternating.
In a dielectric duplexer in which the orientation of the open surface and the short-circuit surface are alternately switched, a manufacturing process in which a plurality of coaxial dielectric resonators are individually manufactured and then these coaxial dielectric resonators are joined to each other is adopted. Therefore, it is possible to omit the formation of the step which is necessary in the conventional monoblock type dielectric duplexer.

In a more specific configuration, the dielectric block of the coaxial dielectric resonator that constitutes the resonator filter for transmission is different from the dielectric block of the coaxial dielectric resonator that constitutes the resonator filter for reception. It is made of a dielectric material having a dielectric constant.
According to the specific configuration, even if there is a large gap between the reception band and the transmission band, the dielectric constant of the dielectric block of the coaxial dielectric resonator constituting the transmission resonator filter, and the reception band By separately adjusting the dielectric constant of the dielectric block of the coaxial dielectric resonator constituting the resonator filter, both coaxial dielectric resonators can be formed to have the same length. As a result, it becomes possible to form the entire dielectric duplexer in a rectangular parallelepiped without any step, and thereby, the exclusive area when the dielectric duplexer is mounted on the circuit board can be effectively utilized. In addition, the dielectric duplexer can realize high characteristics as a whole by combining different characteristics for each coaxial dielectric resonator.

  According to the dielectric duplexer according to the present invention, the high frequency component passing through the transmission / reception resonator filter is sufficiently suppressed to prevent the occurrence of the spurious mode, and between the transmission terminal and the reception terminal. Isolation characteristics are improved.

Hereinafter, embodiments of the present invention will be specifically described with reference to the drawings.
First Embodiment As shown in FIG. 1, the dielectric duplexer (1) of the present embodiment is formed by juxtaposing three coaxial dielectric resonators (2), (3) and (4). The resonators are joined and integrated with each other on each side.

The central coaxial dielectric resonator (2) is a rectangular parallelepiped dielectric block (21) having two through holes (23) and (24), and the front, back and both sides of the dielectric block (21). The conductor layer (22) formed on the back surface and the inner peripheral surface of the through holes (23) (24), and the antenna terminal (11) is formed by a part of the conductor layer (22). ing.
In the coaxial dielectric resonator (2), the conductor layer (22) on the front surface of the dielectric block (21) is deleted to form an open surface (20), and the back surface of the dielectric block (21) is formed. A short-circuit surface (25) is formed by the covering conductor layer (22).

The right coaxial dielectric resonator (3) includes a rectangular parallelepiped dielectric block (31) having two through holes (33) and (34), and the front, back and both sides of the dielectric block (31). And a conductor layer (32) formed on the back surface and the inner peripheral surface of the through holes (33) and (34), and a transmission terminal (12) is formed by a part of the conductor layer (32). ing.
In the coaxial dielectric resonator (3), the conductor layer (32) on the front surface of the dielectric block (31) is deleted to form an open surface (30), and the back surface of the dielectric block (31) is A short-circuit surface (35) is formed by the covering conductor layer (32).

The left coaxial dielectric resonator (4) includes a rectangular parallelepiped dielectric block (41) having two through holes (43) and (44), and the front, back and both sides of the dielectric block (41). And a conductor layer (42) formed on the back surface and the inner peripheral surface of the through holes (43) and (44), and a transmission terminal (12) is formed by a part of the conductor layer (42). ing.
In the coaxial dielectric resonator (4), the conductor layer (42) on the front surface of the dielectric block (41) is deleted to form an open surface (40), and the back surface of the dielectric block (41) is formed. A short-circuit surface (45) is formed by the covering conductor layer (42).

  As shown in FIG. 2 (a), on the right side surface of the left coaxial dielectric resonator (4), the central portion has a depth corresponding to the thickness of the conductor layer (42). Groove processing from the front surface to the back surface of the resonator (4) is performed to form a resonator coupling portion (6) lacking the conductor layer (42), and on both sides of the resonator coupling portion (6). A resonator shield part (42a) (42b) is formed of a conductor layer (42) separated into two regions.

As shown in FIG. 2 (b), the conductor on the left side of the central coaxial dielectric resonator (2) is located at a position corresponding to the resonator coupling portion (6) of the left coaxial dielectric resonator (4). Resonator coupling portion (6) lacking conductor layer (22) having a depth corresponding to the thickness of layer (22) and being grooved from the front surface to the back surface of coaxial dielectric resonator (2). ) And resonator shield portions (22a) and (22b) each including a conductor layer (22) separated into two regions are formed on both sides of the resonator coupling portion (6).
Further, the right side surface of the central coaxial dielectric resonator (2) has a depth corresponding to the thickness of the conductor layer (22) at the center thereof, and the surface of the coaxial dielectric resonator (2). The groove from the back to the back surface is processed to form the resonator coupling portion (5) lacking the conductor layer (22), and the two sides of the resonator coupling portion (5) are separated into two regions. A resonator shield part (22c) (22d) made of a conductive layer (22) is formed.

  As shown in FIG. 2 (c), on the left side of the right coaxial dielectric resonator (3), there is a conductor at a position corresponding to the resonator coupling portion (5) of the central coaxial dielectric resonator (2). Groove processing from the front surface to the back surface of the coaxial dielectric resonator (3) having a depth corresponding to the thickness of the layer (32) is performed, and the resonator coupling portion (5 ) And resonator shield portions (32a) and (32b) each including a conductor layer (32) separated into two regions are formed on both sides of the resonator coupling portion (5).

As shown in FIG. 1, the open surfaces (20), (30) and (40) of the three coaxial dielectric resonators (2), (3) and (4) face in the same direction.
Here, the width L1 of the resonator coupling portion (5) formed at the junction between the central coaxial dielectric resonator (2) and the right coaxial dielectric resonator (3), and the central coaxial dielectric resonator. The width L2 of the resonator coupling portion (6) formed at the junction of (2) and the left coaxial dielectric resonator (4) can be set independently and is realized between the resonators. It is adjusted according to the strength of the bond to be done.

Second Embodiment A dielectric duplexer (1) according to the present embodiment is a first embodiment in that three coaxial dielectric resonators (2), (3) and (4) are arranged side by side as shown in FIG. Although it is the same structure as an example, the shape (groove depth) of the resonator coupling part (51) (61) interposed in the junction part of these coaxial dielectric resonators (2) (3) (4) is 1st. This is different from the embodiment.

  That is, as shown in FIG. 4 (a), the coaxial dielectric resonator (4) has a depth larger than the thickness of the conductor layer (42) on the right side surface of the left coaxial dielectric resonator (4). ) From the front surface to the back surface, and a resonator coupling portion (61) in which the conductor layer (42) and a part of the dielectric block (41) are missing is formed. Similarly, resonator shield portions (42a) and (42b) are formed on both sides of the resonator coupling portion (61).

As shown in FIG. 4 (b), the left side surface of the central coaxial dielectric resonator (2) has a depth larger than the thickness of the conductor layer (22), and the coaxial dielectric resonator (2) Groove processing from the front surface to the back surface is performed to form the resonator coupling portion (61) in which the conductor layer (22) and a part of the dielectric block (21) are missing. Similarly, resonator shield portions (22a) and (22b) are formed on both sides of the resonator coupling portion (61).
Further, on the right side surface of the central coaxial dielectric resonator (2), a groove having a depth larger than the thickness of the conductor layer (22) and extending from the front surface to the back surface of the coaxial dielectric resonator (2). As a result, the resonator coupling part (51) in which the conductor layer (22) and a part of the dielectric block (21) are missing is formed. Similarly, resonator shield portions (22c) and (22d) are formed on both sides of the resonator coupling portion (51).

  As shown in FIG. 4 (c), the left side surface of the right coaxial dielectric resonator (3) has a depth larger than the thickness of the conductor layer (32), and the coaxial dielectric resonator (3) has a depth greater than that of the conductor layer (32). Groove processing from the front surface to the back surface is performed to form the resonator coupling portion (51) in which the conductor layer (32) and a part of the dielectric block (31) are missing. Similarly, resonator shield portions (32c) and (32d) are formed on both sides of the resonator coupling portion (51).

Third Embodiment A dielectric duplexer (1) according to the present embodiment is formed by juxtaposing three coaxial dielectric resonators (2), (3), and (4) as shown in FIG. The same configuration as that of the first embodiment in that the resonator coupling portions (5) and (6) are provided, but the open surfaces (30) of the two coaxial dielectric resonators (3) and (4) on both sides are provided. (40) is different from the first embodiment in that the orientation of (40) is opposite to the orientation of the open surface (20) of the central coaxial dielectric resonator (2).

Fourth Embodiment The dielectric duplexer (1) of the present embodiment is constructed by arranging three coaxial dielectric resonators (2), (3) and (4) in parallel as shown in FIG. The same configuration as that of the second embodiment in that the resonator coupling portions (51) and (61) are provided. However, as in the third embodiment, the two coaxial dielectric resonators (3) (3) ( 4) Open surface (30) (40) is different from the second embodiment in that the orientation of the open surface (20) of the central coaxial dielectric resonator (2) is reversed. ing.

Fifth Embodiment The dielectric duplexer (1) of the present embodiment is constituted by arranging three coaxial dielectric resonators (2), (3) and (4) in parallel as shown in FIG. Resonators (2), (3) and (4) have the same configuration as the first embodiment in that the open surfaces (20), (30) and (40) face the same direction, but the central and right coaxial dielectrics. Resonator shields 52 and 53 between the resonators 2 and 3 and resonator shields 62 and 63 between the central and left coaxial dielectric resonators 2 and 4. ) Are recessed along the front surface or the back surface of the coaxial dielectric resonator, open to the front surface or the back surface, and adjacent dielectric blocks are joined to each other without a conductor layer. It is different from the embodiment.
The three coaxial dielectric resonators (2), (3), and (4) are integrated by joining the dielectric blocks together with an adhesive or by filling the groove in the resonator shield part with the adhesive. Has been.

Sixth Embodiment A dielectric duplexer (1) of the present embodiment is constituted by juxtaposing three coaxial dielectric resonators (2), (3) and (4) as shown in FIG. The configuration is the same as that of the third embodiment in that the directions of the open surfaces (20), (30), and (40) of the resonators (2), (3), and (4) are alternately switched, but the coaxial dielectrics at the center and right side Resonator shield part (52) (53) between the body resonators (2) and (3) and a resonator shield part (62) between the center and left coaxial dielectric resonators (2) and (4) ( 63) are recessed along the front surface or the back surface of the coaxial dielectric resonator, open to the front surface or the back surface, and adjacent dielectric blocks are joined to each other without a conductor layer. Different from the third embodiment.
The three coaxial dielectric resonators (2), (3), and (4) are integrated by joining the dielectric blocks together with an adhesive or by filling the groove in the resonator shield part with the adhesive. Has been.

Comparison of characteristics The dielectric duplexer (1) of the fourth embodiment shown in FIG. 6 and the conventional dielectric duplexer (9) shown in FIG. 9 were made as prototypes, and their frequency characteristics and isolation characteristics were measured. As a result, the results shown in FIGS. 10 to 13 were obtained.
10 (a) and 10 (b) show the frequency characteristics of the received signal and the transmitted signal in the dielectric duplexer (1) of the fourth embodiment. FIGS. 11 (a) and 11 (b) show the conventional dielectric duplexer. The frequency characteristic about the received signal and transmission signal in Kusa (9) is represented.
As shown in the figure, in the dielectric duplexer (1) of the fourth embodiment, the spurious mode in the vicinity of 4 GHz generated in the conventional dielectric duplexer (9) is sufficiently suppressed, and the frequency characteristics are improved. It is confirmed that it is done.

FIG. 12 shows the isolation characteristics of the dielectric duplexer (1) of the fourth embodiment, and FIG. 13 shows the isolation characteristics of the conventional dielectric duplexer (9).
As shown in the figure, in the dielectric duplexer (1) of the fourth embodiment, attenuation of 54.9 dB is obtained in the transmission band Tx and 43.5 dB in the reception band Rx, and the conventional dielectric duplexer ( The attenuation amount larger than the attenuation amount 50.0 dB of the transmission band Tx and the attenuation amount 40.8 dB of the reception band Rx in 9) is obtained, confirming that the isolation characteristics are improved.

  Further, in the production of the dielectric duplexer (1) in which the orientations of the open surface and the short-circuit surface of the three coaxial dielectric resonators (2), (3) and (4) are alternately switched, these coaxial dielectric resonators are manufactured. (2) (3) (4) can be separately manufactured and then bonded to each other, so that it is possible to omit the step formation that was necessary in the conventional monoblock type dielectric duplexer. I can do it.

  When dielectric materials having different dielectric constants are used as the materials of the dielectric blocks (21), (31) and (41) constituting the three coaxial dielectric resonators (2), (3) and (4), High characteristics as a whole can be realized by combining different characteristics for each dielectric resonator. However, even if there is a large gap between the reception band and the transmission band, by adjusting the dielectric constants of the three coaxial dielectric resonators (2), (3), and (4) individually, these coaxial dielectrics The body resonators can have the same length in the axial direction. As a result, it becomes possible to form the entire dielectric duplexer (1) in a rectangular parallelepiped with no steps, thereby effectively utilizing the exclusive area when the dielectric duplexer (1) is mounted on a circuit board. I can do it.

  Furthermore, in the production of the dielectric duplexer (1) according to the present invention, the resonator coupling portions (5) and (6) can be formed by groove processing, so that the groove widths (L1, L2) are gradually increased. It is possible to adjust the band impedance by the work of extending the frequency.

1 is a perspective view of a dielectric duplexer according to a first embodiment of the present invention. It is a disassembled perspective view of this dielectric duplexer. It is a perspective view of the dielectric duplexer of 2nd Example. It is a disassembled perspective view of this dielectric duplexer. It is a perspective view of the dielectric duplexer of 3rd Example. It is a perspective view of the dielectric duplexer of 4th Example. It is a top view of the dielectric duplexer of 5th Example. It is a top view of the dielectric duplexer of 6th Example. It is a perspective view of the conventional dielectric duplexer. It is a graph showing the frequency characteristic of the dielectric duplexer which concerns on this invention. It is a graph showing the frequency characteristic of the conventional dielectric duplexer. It is a graph showing the isolation characteristic of the dielectric duplexer which concerns on this invention. It is a graph showing the isolation characteristic of the conventional dielectric duplexer. It is a block diagram which shows the structure of a mobile communication apparatus.

Explanation of symbols

(1) Dielectric duplexer
(11) Antenna terminal
(12) Transmission terminal
(13) Reception pin
(2) Coaxial dielectric resonator
(20) Open surface
(21) Dielectric block
(22) Conductor layer
(3) Coaxial dielectric resonator
(30) Open surface
(31) Dielectric block
(32) Conductor layer
(4) Coaxial dielectric resonator
(40) Open surface
(41) Dielectric block
(42) Conductor layer
(5) Resonator coupling part
(6) Resonator coupling part
(51) Resonator coupling
(61) Resonator coupling
(22a) to (22d) Resonator shield
(32a) (32b) Resonator shield
(42a) (42b) Resonator shield

Claims (7)

An antenna terminal to which an antenna is to be connected; a transmission terminal to which a transmission circuit is to be connected; and a reception terminal to which a reception circuit is to be connected; and a transmission terminal between the antenna terminal and the transmission terminal. In the dielectric duplexer in which the resonator filter is configured and the resonator filter for reception is configured between the antenna terminal and the reception terminal,
A first coaxial dielectric resonator provided with the antenna terminal, a through-hole that functions as a part of a resonator filter for transmission, and a through-hole that functions as a part of a resonator filter for reception; ,
A second coaxial dielectric resonator provided with a through hole that functions as a part of the transmitting terminal and a transmitting resonator filter;
The receiving terminal and a third coaxial dielectric resonator provided with a through-hole functioning as a part of the receiving resonator filter;
Each coaxial dielectric resonator includes a through hole formed in the dielectric block, and a conductor layer formed on the front surface, back surface, both side surfaces, the back surface of the dielectric block, and the inner peripheral surface of the through hole,
Each of the two resonator filters for transmission and reception is configured by juxtaposing the coaxial dielectric resonators,
Each of the two resonator filters for transmission and reception has a joint part joined between the side surfaces of two adjacent coaxial dielectric resonators, and a conductor is provided between the dielectric blocks at the joint part. 2. A dielectric duplexer comprising: a resonator shield part including a layer; and a resonator coupling part formed by removing a conductor layer between dielectric blocks.   Grooves extending from the front surface to the back surface of the coaxial dielectric resonator are recessed in the two side surfaces to be joined to each other of the two coaxial dielectric resonators. The dielectric duplexer according to claim 1, wherein the resonator coupling portion is formed.   3. The dielectric duplexer according to claim 2, wherein the groove is recessed at a center portion of the joint surface separated from the front surface and the back surface of the coaxial dielectric resonator. An antenna terminal to which an antenna is to be connected; a transmission terminal to which a transmission circuit is to be connected; and a reception terminal to which a reception circuit is to be connected; and a transmission terminal between the antenna terminal and the transmission terminal. In the dielectric duplexer in which the resonator filter is configured and the resonator filter for reception is configured between the antenna terminal and the reception terminal,
A first coaxial dielectric resonator provided with the antenna terminal, a through-hole that functions as a part of a resonator filter for transmission, and a through-hole that functions as a part of a resonator filter for reception; ,
A second coaxial dielectric resonator provided with a through hole that functions as a part of the transmitting terminal and a transmitting resonator filter;
The receiving terminal and a third coaxial dielectric resonator provided with a through-hole functioning as a part of the receiving resonator filter;
Each coaxial dielectric resonator includes a through hole formed in the dielectric block, and a conductor layer formed on the front surface, back surface, both side surfaces, the back surface of the dielectric block, and the inner peripheral surface of the through hole,
Each of the two resonator filters for transmission and reception is configured by juxtaposing the coaxial dielectric resonators,
Each of the two resonator filters for transmission and reception has a joint portion joined between the side surfaces of two adjacent coaxial dielectric resonators, and both coaxial dielectric resonators are connected to the joint portions. Grooves that are open on either or both of the front surface and back surface of the resonator are recessed, and the resonator shield part made of a conductor layer covering the groove and the conductor layer between the dielectric blocks of both coaxial dielectric resonators are omitted. A dielectric duplexer, comprising: a resonator coupling portion.   Each of the plurality of coaxial dielectric resonators has an open surface on which no conductor layer is formed on the front surface of the dielectric in which one end of the through hole is open, and a dielectric block in which the other end of the through hole is open 5. The dielectric duplexer according to claim 1, further comprising: a short-circuit surface having a conductor layer formed on a back surface thereof, wherein open surfaces of all the coaxial dielectric resonators face in the same direction. 6. .   Each of the plurality of coaxial dielectric resonators has an open surface on which no conductor layer is formed on the front surface of the dielectric block in which one end of the through hole is open, and the dielectric block in which the other end of the through hole is open 5. The short-circuit surface having a conductor layer formed on the back surface of each of the plurality of coaxial dielectric resonators, wherein the directions of the open surface and the short-circuit surface are alternately switched. Dielectric duplexer.   The dielectric block of the coaxial dielectric resonator constituting the transmission resonator filter and the dielectric block of the coaxial dielectric resonator constituting the reception resonator filter are made of dielectric materials having different dielectric constants. The dielectric duplexer according to claim 1, wherein the dielectric duplexer is formed.

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