JPH056908U - Dielectric filter - Google Patents

Abstract

(57) [Abstract] [Purpose] When a series resonance capacitor is connected to the inner conductive film of a dielectric resonator to form a dielectric filter that functions as a band elimination filter, the number of parts is reduced to reduce the cost. Reduce and improve productivity. A through hole 5 is formed in the dielectric block 4, an inner conductive film 6 is formed in the through hole 5, and an outer conductive film 7 is formed on the outer surface of the dielectric block 4 except the open end surface 4a.
To form a dielectric resonator 2 that functions as a band elimination filter. Then, the resin member 12
Pin 1 made by inserting metal coupling pin 13 into the shaft core of
1 is inserted into the through hole 5, whereby a series resonance capacitor C is obtained between the inner conductive film 6 and the coupling pin 13.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a dielectric filter that functions as a band elimination filter, and more particularly to a structure that can reduce the number of parts, reduce the cost of parts, and improve productivity.

[0002]

[Prior Art]

 As an example of a dielectric filter having a function of canceling only a signal in a specific frequency range, there is a conventional structure having a structure as shown in FIGS. The dielectric filter 30 is configured by disposing a pair of dielectric coaxial resonators R1 and R2 on a case body 31 and mounting a case cover 32 on the case body 31. A coupling terminal 34 is inserted into the through hole 33 of each of the dielectric coaxial resonators R1 and R2, and the coupling terminal 34 is electrically connected to the inner conductive film formed on the inner peripheral surface of the through hole 33. It is connected to the. A dielectric substrate 35 is provided on each of the coaxial resonators R1 and R2, a ground electrode (not shown) is formed on the entire lower surface of the dielectric substrate 35, and an upper surface is formed on the upper surface. Two capacitor electrode films 36, 36 are formed. Input / output terminals 37, 37 are connected to each capacitor electrode film 36, and each terminal 37 is led out from the opening 32a of the case cover 32. Further, a coil L is connected to both input / output terminals 37 of the dielectric substrate 35, and capacitor chips C1 and C2 are connected to the input / output terminals 37, respectively. The coupling terminals 34 of the coaxial resonators R1 and R2 are connected to the capacitor chips C1 and C2, respectively. Chip capacitors C1 and C2 are connected in series.

[0003]

[Problems to be solved by the device]

 However, the conventional dielectric filter 30 has a structure in which the inner conductive film of each of the dielectric coaxial resonators R1 and R2 and the chip capacitors C1 and C2 are connected by the coupling terminal 34 to obtain a series resonance capacitor. Therefore, there are problems that the number of parts is large, the cost rises accordingly, and the productivity is low. The present invention has been made in view of the above conventional circumstances, and an object thereof is to provide a dielectric filter which can reduce the number of parts to reduce the cost and improve the productivity.

[0004]

[Means for Solving the Problems]

 According to the present invention, a through hole is formed in the core of a dielectric block, and an inner conductive film and an outer conductive film are formed on the inner surface of the through hole and on the outer surface of the dielectric block except the open end surface, respectively. In a dielectric filter that constitutes a body resonator and has a series resonance capacitor connected to the inner conductive film, a solid dielectric pin formed by inserting a metal coupling pin into the axis of a solid dielectric member It is characterized in that it is inserted into the through hole to obtain a series resonance capacitor between the conductive film in the through hole and the connecting pin.

[0005]

[Action]

 According to the dielectric filter of the present invention, the solid dielectric pin is inserted into the through hole of the dielectric resonator, and the series resonance capacitor is obtained between the coupling pin and the inner conductive film. The number of parts can be reduced, and the cost can be reduced accordingly, compared to the case where the conventional coupling terminal and chip capacitor are used. Further, in the present invention, the solid dielectric pin can be assembled simply by inserting it into the through hole, and the number of assembling steps can be reduced as compared with the case where the conventional coupling terminal is inserted and then the terminal and the chip capacitor are connected. The productivity can be improved accordingly.

[0006]

【Example】

 An embodiment of the present invention will be described below with reference to the drawings. 1 and 2 are views for explaining a dielectric filter according to an embodiment of the present invention. In the figure, reference numeral 1 denotes a dielectric filter that functions as a band elimination filter of the present embodiment, which is formed by arranging two dielectric coaxial resonators 2 and 2 in parallel in a metal case 3. The case 3 has a box shape surrounding the front portion of each of the coaxial resonators 2, and each of the coaxial resonators 2 is machined by the solder filled in the half hole 3b formed in the upper wall 3a of the case 3. Are electrically and electrically connected.

Each of the dielectric coaxial resonators 2 is composed of a prismatic dielectric block 4 made of ceramics, and a through hole 5 is formed in the shaft center of the dielectric block 4, and the through hole 5 is formed. An inner conductive film 6 is formed on the inner peripheral surface of the hole 5. An outer conductive film 7 is formed on the four side surfaces and the bottom surface of the dielectric block 4 excluding the open side end surface 4a, and the outer conductive film 7 is electrically connected to the inner conductive film 6.

A strip-shaped insulating substrate 8 made of glass epoxy resin is arranged on the open side end surface 4 a of each coaxial resonator 2. The insulating substrate 8 contacts the front wall 3 c of the case 3. Openings are formed in the portions of the front wall 3c that are in contact with each other and face both ends of the insulating substrate 8. Further, projecting portions 8a are formed at both ends of the lower surface of the insulating substrate 8, and each projecting portion 8a projects from an opening formed in the bottom wall 3d of the case 3. Furthermore, pin holes 8b, 8b are formed on the upper portions of the respective protruding portions 8a of the insulating substrate 8, and a terminal electrode 9 is formed from the peripheral portion of each of the pin holes 8b to the protruding portion 8a. A coil 10 is arranged on the insulating substrate 8, and both ends of the coil 10 are connected to the terminal electrodes 9, 9.

A resin pin (solid dielectric pin) 11 is press-fitted into the through hole 5 on the open end face 4 a side of each dielectric coaxial resonator 2. The resin pin 11 is a resin member (solid dielectric member) formed by integrally forming a cylindrical insertion portion 12a inserted into the through hole 5 and a brim-shaped locking portion 12b that abuts against the open side end surface 4a. 12 and a metal coupling pin 13 inserted and fixed in the axial direction of the resin member 12. One end of the coupling pin 13 projects outward from the resin member 12, and the projecting portion 13a is inserted into each pin hole 8b of the insulating substrate 8 and connected to the terminal electrode 9. As a result, a series resonance capacitor C is formed between the coupling pin 13 of the resin pin 11 and the inner conductive film 6.

Next, the function and effect of this embodiment will be described. The dielectric filter 1 of this embodiment functions as a band elimination filter that blocks only signals in a specific frequency range, and is used in, for example, an antenna duplexer, a duplexer, and the like. According to this embodiment, the resin pin 11 is inserted into the through hole 5 of the dielectric coaxial resonator 2, and the series resonance capacitor C 1 is obtained between the coupling pin 13 of the resin pin 11 and the inner conductive film 6. As a result, the number of parts can be reduced compared to the case where a conventional coupling terminal and a chip capacitor are used, the cost can be reduced accordingly, and the number of assembling steps can be reduced to improve the productivity. Further, in this embodiment, since the coupling pin 13 of the resin pin 11 is connected to the terminal electrode 9 of the insulating substrate 8, the coupling pin 13 can also be used as an input / output terminal, so that a conventional input / output terminal is unnecessary. Therefore, the number of parts can be reduced also from this point.

FIG. 3 and FIG. 4 are views for explaining modified examples of the above-described embodiment, and in the drawings, the same reference numerals as those in FIG. 2 indicate the same or corresponding portions. In the dielectric filter 15 shown in FIG. 3, a resin pin 11 is press-fitted into the through hole 5 of each dielectric coaxial resonator 2, a meander type coil conductor 17 is formed on the surface of an insulating substrate 16, and the coil is formed. In this example, both ends of the conductor 17 are connected to the respective terminal electrodes 9. According to this example, the resin pin 11 provides a series resonance capacitor, and the coupling pin 13 is also used as an input terminal and an output terminal. Therefore, the same effect as that of the above-described embodiment can be obtained, and the insulating substrate 16 is further provided with a coil conductor. Since 17 is patterned, the coil can be eliminated and the number of parts can be further reduced accordingly. In the structure shown in FIG. 4, the protrusion 13a of the coupling pin 13 of the resin pin 11 is further extended, and the extension 22 is protruded from the opening formed in the bottom wall 21a of the case 21. This is an example of a vertical dielectric filter 20. According to this example, since the extension portion 22 of the coupling pin 13 can be directly input and used as an output terminal, it is possible to further reduce the number of parts while obtaining the same effect as that of the above embodiment. In the above-mentioned embodiments and modifications, the one-stage dielectric coaxial resonator 2 is described as an example, but the dielectric resonator of the present invention is not limited to this, and for example, an integrally formed dielectric body. It can also be applied to a dielectric resonator formed by forming a plurality of through holes in a block.

[0012]

[Effect of the device]

 As described above, according to the dielectric filter of the present invention, the resin pin formed by inserting the metal coupling pin into the shaft core of the resin member is inserted into the through hole of the dielectric resonator, and the through hole of the through hole is formed. Since the series resonance capacitor is provided between the inner conductive film and the coupling pin, the number of parts can be reduced, the cost can be reduced, and the productivity can be improved.

[Brief description of drawings]

FIG. 1 is a sectional view illustrating a dielectric filter according to an embodiment of the present invention.

FIG. 2 is an exploded perspective view showing each component of the dielectric filter of the above embodiment.

FIG. 3 is an exploded perspective view showing a modified example of the above embodiment.

FIG. 4 is an exploded perspective view showing another modification of the above embodiment.

FIG. 5 is an exploded perspective view showing a conventional dielectric filter.

FIG. 6 is an equivalent circuit diagram of the conventional dielectric filter.

[Explanation of symbols]

 1, 15 and 20 Dielectric filter 2 Dielectric coaxial resonator 4 Dielectric block 4a Open end face 5 Through hole 6 Inner conductive film 7 Outer conductive film 11 Resin pin (solid dielectric pin) 12 Resin member (solid dielectric member ) 13 coupling pin C series resonance capacitor

Claims (1)

[Claim 1] At least one through hole is formed in the dielectric block, and an inner conductive film is formed in the through hole and on the outer surface of the dielectric block except the open end surface. ，
In a dielectric filter that functions as a band elimination filter by forming an outer conductive film to form a dielectric resonator and connecting a series resonance capacitor to the inner conductive film, a metal is used as the axis of the solid dielectric member. A solid dielectric pin having a coupling pin inserted therein is inserted into the through hole, and a series resonance capacitor is obtained between the conductive film in the through hole and the coupling pin. Body filter.