JP3430570B2 - Dielectric resonator device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dielectric resonator device in which an inner conductor is formed in a dielectric and an outer conductor is formed on an outer surface of the dielectric. 2. Description of the Related Art A dielectric resonator device in which an inner conductor is formed inside a dielectric block or a dielectric block formed by joining dielectric members, and an outer conductor is formed on an outer surface. Are used, for example, as a band pass filter or a band rejection filter in a microwave band. FIG. 11 is an exploded perspective view showing the structure of a conventional general dielectric resonator device using a dielectric block. In FIG. 11, reference numeral 1 denotes a substantially hexahedron-shaped dielectric block having three inner conductor forming holes indicated by 16, 17, and 18, and coupling holes 19 and 20 provided between the inner conductor forming holes. An inner conductor is formed on the inner surfaces of the inner conductor forming holes 16, 17, and 18, and the outer conductor 21 is formed on the other five surfaces except for the open surface indicated by 22.
Is formed. Reference numerals 23, 24 denote so-called resin pins, which are resin portions 23a, 24a and signal input / output terminals 23, respectively.
b, 24b. The two resin pins 23 and 24 are inserted from the open side of the dielectric block to the inner conductor forming holes 16 and 18.
, The terminals 23 b and 24 b are capacitively coupled to the inner conductors in the inner conductor forming holes 16 and 18. Reference numeral 25 denotes a case which holds the dielectric block 1 and the resin pins 23 and 24 and covers the opening surface of the dielectric block. The resin pins 23 and 24 are inserted into the dielectric block 1, respectively, and the case 25 is covered, and the whole is integrated by soldering to the outer conductor 21 of the dielectric block 1. When mounting this dielectric resonator, the protruding portions 25a and 25b of the case 25 are used as ground terminals. However, even if a plurality of resonators are formed in a single dielectric block as shown in FIG. Not only do they require component parts, the assembly process becomes complicated, but also when mounting the finished product on a circuit board, it must be mounted as electronic components with leads, and other components mounted on the same circuit board It cannot be mounted on a surface like electronic components, and it has been difficult to reduce the height. Even if the case 25 is not used by directly connecting the outer conductor 21 of the dielectric block 1 to the ground electrode on the circuit board,
Since the open surface 22 is exposed and an electromagnetic field leak occurs at this portion, when a metal body approaches the open surface, the metal surface is affected by the metal body, and the resonator is coupled with an external electromagnetic field,
The desired characteristics as a dielectric resonator cannot be obtained. An object of the present invention is to provide a dielectric resonator which can be easily surface-mounted on a circuit board without using resin pins 23 and 24 and a case 25 as individual components as shown in FIG. It is to provide a device. Another object of the present invention is to provide a dielectric resonator which suppresses the electromagnetic field leakage between the inside and the outside near the opening to solve the above-mentioned problem caused by the electromagnetic field leakage. A dielectric resonator device according to a first aspect of the present invention is a dielectric block having a substantially rectangular parallelepiped shape.
Of the opposing two surfaces through the open surface, provided the conductor formed holes among the formation of the inner conductor on an inner peripheral surface on the dielectric block,
In a dielectric resonator device having an outer conductor formed on an outer surface of the dielectric block , an open end of the inner conductor is provided inside at least one opening surface of the inner conductor forming hole, and A capacitor is formed in a region surrounding the inner conductor forming hole with the open end of the inner conductor, and the opening of the inner conductor forming hole is formed.
The inner conductor shape extends continuously from the mouth surface into the inner conductor forming hole.
Between the inner conductor and the open end of the inner conductor
And a signal input / output electrode for forming a capacitor . In the dielectric resonator device according to the first aspect of the present invention, the inner conductor is formed on the inner peripheral surface of the inner conductor forming hole in the dielectric, and the outer conductor is formed on the outer surface of the dielectric. Is formed. An open end of the inner conductor is provided near at least one opening surface of the inner conductor forming hole, and a signal input / output electrode is formed in a region of the opening surface surrounding the inner conductor forming hole. Forms a capacitance with the open end of the inner conductor.
Therefore, the inner conductor acts as a resonator, and the capacitance formed between the open end of the inner conductor and the signal input / output electrode acts as an external coupling capacitance. Therefore, signal input / output terminals as individual components such as conventional so-called resin pins are unnecessary, and by mounting on a surface of a circuit board, an outer conductor is connected to a ground electrode on the circuit board, and signal input / output electrodes are connected. Can be easily connected to the signal lines on the circuit board. Further, since the open end of the inner conductor is in the inner conductor forming hole and the outer conductor is formed on the opening surface of the inner conductor forming hole, electromagnetic field leakage from the open end of the inner conductor is suppressed. . In addition, the signal input / output electrode continuously extends from the opening surface of the inner conductor forming hole into the inner conductor forming hole, and a capacitance is provided between the inner end of the inner conductor forming hole and the open end of the inner conductor. Is formed, electromagnetic field leakage from the open end of the inner conductor is more effectively suppressed. Also, by adjusting the position and width of the gap between the signal input / output electrode extending continuously from the opening surface of the inner conductor forming hole into the inner conductor forming hole and the open end of the inner conductor in the inner conductor forming hole. Although the axial length of the conductor (resonator length) and the external coupling capacitance can be adjusted, only the external coupling capacitance can be adjusted by adjusting the width of the gap without changing the axial length of the inner conductor. Therefore, a dielectric resonator device having desired characteristics can be easily manufactured. FIG. 1 is a perspective view showing the appearance of a dielectric resonator device according to a first embodiment of the present invention. In FIG. 1, a dielectric block 1 has a substantially hexahedral shape, and has four side surfaces S3, S4, S5, S6 continuous between a first surface S1 and a second surface S2 opposed thereto. And inner conductor forming holes 2a, 2b, 2c penetrating between the first surface S1 and the second surface S2. First surface S1, second surface S2, and four side surfaces S3, S of dielectric block 1
4, S5, and S6, the outer conductor 6 is formed on substantially the entire surface, and the inner peripheral surfaces of the inner conductor forming holes 2a, 2b, 2c are opened by gaps near the openings of the respective inner conductor forming holes on the first surface S1. An inner conductor having an end is formed. Further, on the first surface S1 of the dielectric block 1, a signal input / output electrode 7a is provided in a region surrounding the inner conductor forming holes 2a and 2c independently of the outer conductor 6 provided on the first surface S1 and the side surface S3. , 7b. FIGS. 2A and 2B are cross-sectional views of the dielectric resonator device shown in FIG. 1, wherein FIG. 2A is a cross-sectional view taken along the line XX in FIG. 1, and FIG. It is a longitudinal cross-sectional view. As shown in FIG. 2, the inner conductor forming holes 2a, 2b, 2c
Are formed on the inner peripheral surface of the inner conductor 3a, 3b and 3c, respectively. The signal input / output electrodes 7a, 7b extend a predetermined length from the opening surfaces of the inner conductor forming holes 2a, 2c into the inner conductor forming holes, and have gaps 5a, 5c between the inner conductors 3a, 3c.
Is formed. Also, the first surface S1 of the inner conductor forming hole 2b
The outer conductor 6 extends inward from the side opening surface by a predetermined length to form the tip conductor 4, and a gap 5b is formed between the tip conductor 4 and the inner conductor 3b. Thus, the gaps 5a, 5c
The external coupling capacitance Ce is formed in the portion, and the tip capacitance Cs is formed in the gap 5b. The gaps 5a, 5b, 5c
A conductor is previously formed on the entire surface of the inner conductor forming holes 2a, 2b, 2c, and the inner conductor at a predetermined location in the inner conductor forming hole is removed (cut) in the inner circumferential direction by a rotating grindstone (ruthe).
It forms by doing. At this time, the inner conductor 3 depends on the position and width of the gaps 5a and 5c in the inner conductor forming hole.
Adjust the axial length (resonator length) of a and 3c and the external coupling capacitance. Further, the axial length (resonator length) and the tip capacitance of the inner conductor 3b are adjusted according to the position and width of the gap 5b in the inner conductor forming hole. In this way, the external coupling capacitance can be adjusted in the same manner as the adjustment of the resonance frequency and the tip capacitance of each stage. FIG. 3 is an equivalent circuit diagram of the dielectric resonator device shown in FIGS. In FIG. 3, Ra, Rb,
Rc is a coaxial resonator composed of the inner conductors 3a, 3b, 3c shown in FIG. In this manner, a band-pass filter including three resonators is formed. Next, FIG. 4 shows an external perspective view of a dielectric resonator device according to a second embodiment. In addition, Y- in FIG.
FIG. 5 shows a vertical sectional view of the Y portion. The difference from the first embodiment is that the signal input / output electrodes 7a and 7b are formed only on the first surface S1 of the dielectric block 1. Even when the signal input / output electrodes 7a and 7b are formed as described above, an external coupling capacitance Ce is formed between the signal input / output electrodes 7a and 7b and the inner conductors 3a and 3c as shown in FIG. FIG. 6 is an external perspective view of a dielectric resonator device according to a third embodiment. The difference from the first and second embodiments is that the signal input / output electrodes 7a and 7b extend to a part of the side surface S3 of the dielectric block 1. According to this configuration, when mounting with the side surface S3 of the dielectric block 1 facing the circuit board with the bottom as the bottom, the signal input / output electrodes face the electrodes or the wiring lines on the circuit board, so that the connection is more securely performed. become able to. Further, it is possible to connect the signal input / output electrodes 7a and 7b to the circuit board without attaching a bonding material such as solder to the portions formed on the S1 surface. Next, FIG. 7 shows an external perspective view of a dielectric resonator device according to a fourth embodiment. In the first to third embodiments, a three-stage dielectric resonator device acting as a band-pass filter has been described as an example. However, the one shown in FIG. 7 is a one-stage dielectric resonator device. The block 1 has a substantially hexahedral shape, and has four continuous side surfaces S3, S4, S5, and S6 between a first surface S1 and a second surface S2 opposed thereto, and the first surface S1 and An inner conductor forming hole 2 penetrating between the second surfaces S2 is formed. First surface S of dielectric block 1
1, the outer conductor 6 is formed on substantially the entire surface of the second surface S2 and the four side surfaces S3, S4, S5, and S6, and the inner peripheral surface of the inner conductor forming hole 2 has an opening in the first surface S1 of the inner conductor forming hole. An inner conductor having an open end near the gap is formed. Further, on the first surface S1 of the dielectric block 1, a signal input / output electrode 7 is formed in a region surrounding the inner conductor forming hole 2 independently of the outer conductor 6 provided on the first surface S1 and the side surface S3. are doing. By using such a single-stage dielectric resonator device, it can be used as a band-pass filter or a band-stop filter. Further, a similar one-stage dielectric resonator device may be provided in parallel on a circuit board or the like, and a multi-stage dielectric resonator device may be configured by combination with an electrode pattern on the circuit board. Next, a perspective view of a dielectric resonator device according to a fifth embodiment is shown in FIG. The difference from the first to third embodiments is that the number of resonators is four and that the coupling between the resonators is an interdigital type. In the example shown in FIG.
The inner conductor in the inner conductor forming holes 2a and 2c is the dielectric block 1
The open end is arranged on the first surface S1 side of the inner conductor forming hole 2
The inner conductors in b and 2d form open ends on the second surface S2 side. Also, one signal input / output electrode 7a provided on the first surface S1 forms an external coupling capacitance between the signal input / output electrode 7a and the open end of the inner conductor in the inner conductor forming hole 2a, and the other provided on the second surface S2. The signal input / output electrode 7b forms an external coupling capacitance with the open end of the inner conductor in the inner conductor forming hole 2d. In this way, a dielectric resonator device acting as a band-pass filter including four resonators is configured. Next, FIG. 9 shows an external perspective view of a dielectric resonator device according to a sixth embodiment. The difference from the first to third embodiments is that the number of resonators is five and that one signal input / output electrode is provided over the fourth and fifth inner conductor forming holes. . In FIG. 9, the signal input / output electrode 7a forms an external coupling capacitance with the open end of the inner conductor in the inner conductor forming hole 2a, and the other signal input / output electrode 7b forms the inner conductor forming hole 2a.
Capacitors are formed between d and the open end of the inner conductor in 2e, respectively. FIG. 10 is an equivalent circuit diagram of the dielectric resonator device shown in FIG. In FIG. 10, Ra to Re are coaxial resonators formed by inner conductors formed in the inner conductor forming holes 2a to 2e shown in FIG. With this configuration, a dielectric resonator device that functions as a band-pass filter having an attenuation pole on the high band side or the low band side of the pass band is configured by setting the resonance frequency fo of the fifth-stage resonator Re. . In each of the above-described embodiments, an example is shown in which a dielectric block formed by integral molding is used. For example, a groove having a semicircular cross section is formed on one surface in advance to form an inner conductor and an outer conductor. The two dielectric substrates described above may be joined to form a dielectric block. According to the present invention, surface mounting can be easily performed on a circuit board without using a resin pin or a case as an individual component. Further, the electromagnetic field leakage between the inside and outside near the opening is suppressed, and a dielectric resonator device having stable characteristics can be obtained. Further, the external coupling capacitance between the inner conductor and the signal input / output electrode can be adjusted by the width of the gap between the open end of the inner conductor inside the inner conductor forming hole and the signal input / output electrode, and the dielectric resonator device has desired characteristics. Can be easily manufactured.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an external perspective view of a dielectric resonator device according to a first embodiment. FIG. 2 is a sectional view of the dielectric resonator device shown in FIG. 1,
FIG. 2A is a cross-sectional view taken along a line X-X in FIG. 1, and FIG. FIG. 3 is an equivalent circuit diagram of the dielectric resonator device shown in FIG. FIG. 4 is an external perspective view of a dielectric resonator device according to a second embodiment. FIG. 5 is a sectional view taken along the line YY in FIG. FIG. 6 is an external perspective view of a dielectric resonator device according to a third embodiment. FIG. 7 is an external perspective view of a dielectric resonator device according to a fourth embodiment. FIG. 8 is a perspective view of a dielectric resonator device according to a fifth embodiment. FIG. 9 is an external perspective view of a dielectric resonator device according to a sixth embodiment. 10 is an equivalent circuit diagram of the dielectric resonator device shown in FIG. FIG. 11 is an exploded perspective view of a conventional dielectric resonator device. [Description of Signs] 1-dielectric block 2a-2e-inner conductor forming hole 3a-3c-inner conductor 4-tip conductor 5a-5c-gap 6-outer conductor 7a, 7b-signal input / output electrode

──────────────────────────────────────────────────の Continued on the front page (72) Inventor Tatsuya Tsujiguchi 2-26-10 Tenjin, Nagaokakyo-shi, Kyoto Prefecture Inside Murata Manufacturing Co., Ltd. (72) Inventor Hitoshi Tada 2-26-10 Tenjin, Nagaokakyo-shi, Kyoto In Murata Manufacturing Co., Ltd. (56) References JP-A-4-51602 (JP, A) JP-A-5-183309 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01P 1/20-1/219 H01P 7/00-7/10

Claims (1)

(57) [Claims] [Claim 1] Opposite to a substantially rectangular parallelepiped dielectric block
An inner conductor forming hole penetrating through the two surfaces as opening surfaces and forming an inner conductor on an inner peripheral surface of the dielectric block ;
In a dielectric resonator device having an outer conductor formed on an outer surface of a block , an open end of the inner conductor is provided near at least one opening surface of the inner conductor forming hole, and the inner conductor forming hole is formed on the opening surface. A capacitor is formed in a region surrounding the hole with the open end of the inner conductor, and the inner conductor is continuously formed from the opening surface of the inner conductor forming hole.
Extending into the body forming hole and recessed inside the inner conductor forming hole.
A dielectric resonator device in which a signal input / output electrode for forming a capacitance between the open end of the inner conductor and the open end is formed .