JPS63263802A - Dielectric resonator - Google Patents

Abstract

PURPOSE:To adjust a resonance frequency extending over a wide range without lowering no-load Q, by forming a through hole in a direction orthogonal to the central axis of an internal dielectric, and providing a tuning bar on which a bar material made of a ceramics material with a low permittivity is joined in such a way that it can be inserted in and extracted from a bar material with the same material as that of the internal dielectric. CONSTITUTION:The internal dielectric 1 is made of the dielectric material with a high permittivity such as titanium oxide group ceramics, etc., and the through hole H2 is formed in the direction orthogonal to the central axis. At the tip part of the tuning bar 2, one tuning bar is formed by bonding a cylindrical bar material 2a with the same length as the diameter and made of the same material as that of the internal dielectric 1 and a cylindrical bar material 2b made of the same material as that of a case with glaze, etc, By inserting the tip part of the tuning bar into the through hole H2 of the internal dielectric 1 by inserting the tuning bar 2 from the through hole H1 of a side plate after assembling the case and the internal dielectric, the resonance frequence is adjusted.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Industrial Application Field The present invention relates to a dielectric resonator equipped with a tuning mechanism.

(b) Conventional technology T M o +. Or T M It. Various structures have been devised for adjusting the resonant frequency of the dielectric resonator in its deformation mode.

FIGS. 3, 4, and 5 are diagrams showing the structure of this type of conventional dielectric resonator. In Fig. 3, l represents a columnar internal dielectric, and case 3 in which a metal film is formed on the inner wall.
a, 3b, and 3c. This internal dielectric 1
A region not in contact with the top surface conductor of the case is formed at the center of one end surface of the case, and a resonant frequency adjustment member 2 having an electrode film formed on the surface is arranged in this region. The resonant frequency is adjusted by moving it in the far and near directions with respect to the dielectric 1. Furthermore, in the dielectric resonator shown in FIG. 4, a notch is formed in the side surface of the internal dielectric 1, and a dielectric member 2, which is a resonance frequency adjusting member, is provided in and out of the notch. ing. 5(A) and CB) are horizontal cross-sectional views of the cutout portion of the internal dielectric 1 in FIG. 4, and the resonance frequency is adjusted by rotating the dielectric member 2. FIG.

(The problem that the C1 invention aims to solve However, in such a conventional dielectric resonator,
The amount of change in the resonance frequency with respect to the amount of movement of the resonance frequency adjustment member is large, making it difficult to make fine adjustments. That is, in the dielectric resonator having the structure shown in FIG.
The capacitance of this gap changes greatly due to the vertical movement of the resonant frequency adjusting member 2, and accordingly, the resonant frequency also changes rapidly. In the dielectric resonator having the structure shown in FIG. 4 and FIG. It does not change smoothly as the member 2 rotates.

SUMMARY OF THE INVENTION An object of the present invention is to provide a dielectric resonator that has a wide adjustment range of resonant frequency and that can easily adjust the resonant frequency by reducing the amount of change in the resonant frequency due to movement of a resonant frequency adjusting member. be.

Means for Solving the H61 Problem The dielectric resonator of the present invention has a columnar internal dielectric arranged inside the case, and both ends of the internal dielectric are joined to the inner wall surface of the case. A through hole is formed in the direction perpendicular to the central axis of the dielectric, and a tuning rod made of a low dielectric constant ceramic material is bonded to a rod made of the same material as the internal dielectric. It is characterized by being provided so that it can be inserted into and removed from the through hole.

(e) Function In the dielectric resonator of the present invention, a through hole is formed in a direction perpendicular to the central axis of the internal dielectric, and a low permittivity, electric constant material is used in the rod made of the same material as the internal dielectric. By inserting a tuning rod made of joined rods made of into the through-hole of the internal dielectric, and changing the amount of insertion, the depth of the hole drilled from the side of the internal dielectric changes equivalently. It turns out. As a result, the perturbation effect changes and the resonant frequency changes. At this time, the electric field strength is strong in the central part of the internal dielectric, and the perturbation effect of the electric field energy depending on the insertion depth of the tuning rod is large, so that the resonant frequency can be adjusted over a wide range. Furthermore, the resonance frequency changes relatively linearly with respect to the amount of insertion of the tuning rod, and adjustment can be easily performed. A partially cutaway perspective view and a vertical sectional view showing the structure of the container are shown respectively. In both figures, 3a is the side plate of the case;
b represents the bottom plate, and 3C represents the top plate.Ag electrode film is baked on the ceramic temporary surface whose linear expansion coefficient matches that of the internal dielectric, and each plate is bonded with Ag paste etc. to form the case. It is configured. A cylindrical internal dielectric 1 is disposed between a bottom plate and a top plate in this case, and both ends of the internal dielectric are connected to the inner wall surface of the case by Ag electrodes or the like. Signal input/output connectors 4 (the other one is not shown) are formed at two opposing corners of the top plate 3C, and at the bottom thereof, as shown in FIG.
etc. are provided, and input and output of signals is performed through the connector 4 and the like. In this way, the so-called T M r
A lo modified dielectric resonator is constructed.

The internal dielectric L is made of a dielectric material with a high dielectric constant such as titanium oxide ceramic, and has a through hole H in the direction perpendicular to the central axis.
2 is formed. Reference numeral 2 designates a tuning rod to be inserted into this through hole, and the tip part is a cylindrical rod 2a made of the same material and having approximately the same length as the diameter of the internal dielectric 1, and a cylindrical rod 2a made of the same material as the case. A single tuning rod is formed by bonding the materials 2b with glaze or the like. As shown in the figure, one side plate of the case is formed with a through hole H1 through which the tuning rod passes, and after assembling the case and internal dielectric, the tuning rod 2 is inserted through the through hole H1 of the side plate to perform tuning. By inserting the tip of the rod into the through hole H2 of the internal dielectric 1, the resonance frequency can be adjusted. After adjusting the resonance frequency, the tuning rod 2 can be easily fixed by applying epoxy adhesive to the part where the tuning rod 1 passes through the side plate 3a of the case and drying it. By changing the diameter and dielectric constant, the insertion amount of the tuning rod and the adjustment range of the resonance frequency can be changed. Further, in the embodiment, the supporting portion 2b of the tuning support is made of the same material as the case, but any material may be used as long as it has substantially the same coefficient of linear expansion as the case and has a low dielectric constant. As described above, since the tuning rod is inserted in the center of the cylindrical dielectric body where the electric field strength is large, the perturbation effect of the electric field energy is large (and the resonant frequency can be adjusted over a wide range. According to experiments, when a tuning plug with a diameter of 5fl is inserted into and removed from a dielectric internal dielectric with a diameter of 20n, if the center frequency is f and the frequency change range is Δr, Δf/f = 1.9%.
The frequency change was obtained. In addition, the change in frequency due to the amount of insertion of the tuning rod is linear, and the amount of frequency change due to movement of the tuning rod per unit length is small.
According to experiments, the amount of frequency change with respect to the resonance frequency is 0.1
It is also possible to adjust in % units. Furthermore, according to the embodiment of the present invention, the no-load Q for changes in the resonant frequency is
It was found that the change was small. This is thought to be due to the fact that only the dielectric rod is used as the frequency adjustment member. According to the experiment, when 20 tuning rods were inserted under the same conditions as above, the no-load Q became Q. If expressed as,
ΔQo /Qo = 2.6%.

In addition, the example is TM. Regarding the modified dielectric resonator, T M o +. The present invention can be similarly applied to a TM mode dielectric resonator in which the modes are equal.

(g) Effects of the Invention As described above, according to the present invention, the resonant frequency can be adjusted over a wide range without reducing the no-load Q, and the dielectric resonance can be easily finely adjusted. can be configured.

[Brief explanation of drawings]

FIG. 1 is a partially cutaway perspective view showing the structure of a dielectric resonator according to an embodiment of the present invention, FIG. 2 is a vertical sectional view showing the structure of the dielectric resonator, FIGS. 3, 4, and Figure 5 (A),
(B) is a diagram showing the structure of a conventional dielectric resonator. 1- internal dielectric, 2- tuning rod.

Claims (1)

[Claims] (1) In a dielectric resonator in which a columnar internal dielectric is placed inside the case, and both ends of this internal dielectric are joined to the inner wall of the case, a through hole is formed in a direction perpendicular to the central axis of the internal dielectric. A dielectric resonance device characterized in that a tuning rod made of a rod made of a low dielectric constant material is attached to a rod made of the same material as the internal dielectric, so that it can be inserted into and removed from the through hole of the internal dielectric. vessel.