JPS58108801A - Coaxial type dielectric resonator - Google Patents

Abstract

PURPOSE:To obtain a coaxial type dielectric resonator which is free of spurious phenomena of high degree, or an integral multiple and has small-sized structure, high Q, superior oscillation resistance, and less variance in manufacture. CONSTITUTION:The internal circumferential surface of a dielectric material 4 is coated with silver paste, etc., for forming a conductor layer 8, and the surface of the projecting part 7 of a dielectric material 3 which contacts it is treated similarly to form a conductor layer 9. Those two dielectric materials are engaged with each other to constitute the resonator. Then, conductor films are formed as external conductors 10 over the outer circumference of the resulting body, and conductor films are formed over the internal circumferential surface of the dielectric material 3 to obtain internal conductors 11; and a conductor film 12 is formed on one end surface to connect the external conductor film 10 and internal conductor film 11 together, and a conductor film 13 is formed on the other end surface to connect the internal conductor film to the conductor layer 8 or 9.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a coaxial dielectric resonator, and provides a coaxial dielectric resonator that is small in size, has excellent vibration resistance characteristics, and has little manufacturing variation.

Conventionally, coaxial resonators have been used to generate waves of λ using high-permittivity materials.
λ There is a resonator constructed of long and short coaxial lines or coaxial lines. These resonators have the disadvantage that high-order spurious resonances appear prominently at integral multiple frequencies. In order to improve this, conventional attempts have been made to provide dielectric materials 3 and 4 with different dielectric constants between the outer conductor 2 and the inner conductor 1 using a strong oscillator as shown in FIG. In such a configuration, when actually assembling the resonator, it becomes uncertain whether the different dielectric materials are bonded or fixed to each other, and it is also disadvantageous when adjusting the resonant frequency or making the resonator smaller. It has a certain point.

As another conventional example, as shown in FIG. 2, a cylindrical outer conductor 6
It has been considered that the center conductor 6 is formed in one end with one end open and the other end short-circuited, and a dielectric material 4 is mounted on a part of the open end side. Although this method largely solves the above problems, actual assembly requires consideration of variations and requires considerable machining accuracy of the material. In other words, since a dielectric material is inserted between the inner and outer conductors, a small gap is created between the conductor wall surface and the material, which has a large effect on the resonant frequency and also makes the vibration resistance and temperature characteristics unstable. Make it. The present invention provides a resonator that eliminates these various drawbacks, and further provides a resonator that is advantageous in terms of miniaturization and high Q.

Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings. 3 and 4 show an embodiment of the present invention, in which a dielectric material 3 having the shape shown in FIG. 3 and a dielectric material 4 having the shape shown in FIG. 4 are separately prepared.

These can be easily manufactured by press molding and sintering. Then, the dielectric material 4 shown in FIG. 4 is fitted into the convex portion 7 of the dielectric material 3 shown in FIG. A conductor layer 9 is provided by applying a silver paste or the like to the surface of the convex portion 7 of the dielectric material 3 in contact with the surface of the convex portion 7 in the same manner. Figure 3,
FIG. 5 shows the structure of the resonator of the present invention in which the two dielectric materials 3 and 4 shown in FIG. 4 are fitted together. In this case, after fitting the dielectric materials 3 and 4, an outer conductor coating is formed on the outer periphery of the dielectric materials 3 and 4 to form an outer conductor 10, and an inner conductor coating is formed on the inner circumference of the dielectric material 3. An inner conductor 11 is formed, and a conductor l film 12 is further formed on one end surface to connect the outer conductor coating 1o and the inner conductor coating 11, and an inner conductor coating 1 is formed on the other end surface.
1 and the conductor layer 8 or 9.
form. Silver paste or the like is used for these conductor coatings, and after application, baking is performed in a high temperature furnace to form a conductor coating with good electrical conductivity. The gap between the dielectric material 3 and the dielectric material 4 that are in contact with each other via the conductor layers 8 and 9 may be at least several times the skin depth, and is usually between 2077 m and 1 oool 1.
Take it to m position. In this case, not only is assembly easy, but the conductor is filled between the dielectric materials 3 and 4, so there is an advantage that there is no variation in resonance frequency. Another advantage is that the two dielectric materials are firmly bonded and fixed.

Furthermore, as shown in FIG. 6, this resonator uses conductor layers 8 and 9 to bond the dielectric material 3 and dielectric material 4, resulting in a double coaxial resonator. A much smaller size than the conventional resonator shown in FIG. 1 is achieved. Moreover, since the space can be utilized to the maximum, there is little deterioration in Q. The dielectric material 3 is preferably a material with a low dielectric constant but with as small a dielectric loss as possible. Cheap and stable materials such as alumina and forsterite are suitable. On the other hand, dielectric material 4. ! :The volume used is small, and in order to achieve miniaturization, a material having a dielectric constant equal to or higher than that of the dielectric material 3 is suitable. The resonance condition is the formula 1% formula % (:) Here, the dielectric constant of the dielectric material 3.4 is 81. .

Let εr2 be the inner conductor radius of the dielectric material 3, γ1. The inner conductor radius of the dielectric material 4 is γ61. The radius of the outer conductor is γ.

According to this, for example, forsterite (εr=6) is used as the dielectric material 3, and a high dielectric constant material (
If εr=85) is used, the resonator length can be shortened to less than 100 nm.

FIG. 4 shows another embodiment of the invention. This is a dielectric material 4 made longer by Δl, and by changing this portion by polishing or the like, the resonant frequency can be adjusted even after the resonator has been baked with high-temperature silver.

As described above, according to the present invention, it is possible to construct a small, high-Q resonator without integer multiple higher-order spurious components with good reproducibility and by an easy assembly method. The present invention realizes a two-city coaxial resonator, which has excellent performance but has a slightly complicated structure, at the same time as the effect of adhesive fixing of two types of dielectric materials, making it an extremely useful resonator. It provides:

In the above embodiment, it is assumed that the cross section perpendicular to the axis is circular, but it goes without saying that the same effect can be obtained even if the cross section is rectangular.

The resonator according to the present invention can be used in all kinds of telecommunication equipment. In particular, in response to the recent trend of miniaturization of equipment, it is applied to filters, oscillators, etc., and is expected to be mass-produced, making it extremely useful industrially.

[Brief explanation of the drawing]

FIGS. 1 and 2 (&) are vertical cross-sectional views of a conventional coaxial dielectric resonator, FIGS. 3(b) and 4(a) are cross-sectional views of the same, and FIGS. FIG. 6(b) is a longitudinal cross-sectional view of parts used in the dielectric resonator, FIG. 6(2L) is a longitudinal cross-sectional view of the dielectric resonator in the first embodiment of the present invention, (bl is a cross-sectional view of the same, and FIG. 6 is a vertical cross-sectional view showing another embodiment of the present invention. 3.4... Dielectric material, 8.9... Conductor layer, 1
o...Outer conductor, 11 - Inner ring, 12, 13
...Conductor coating. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure (α) (b) @4 Figure 5 (αl (b
]Figure 6

Claims (4)

[Claims] (1) A ring-shaped second dielectric material having an open end or a protrusion of a first dielectric material having an inner conductor, and being fitted into the protrusion through a conductor layer. an outer conductor is formed on the outer periphery of the first and second dielectric materials, the outer conductor and the inner conductor are connected by a conductor coating provided on the shorted end surface, and the conductor A coaxial dielectric resonator characterized in that a layer and an inner conductor are connected by a conductive coating provided on an open end surface. (2) The conductor layer provided at the fitting part between the protrusion of the first dielectric material and the inner circumferential surface of the ring-shaped second dielectric material is made of a good conductor such as silver paste, which is thicker than the skin depth. A coaxial dielectric resonator according to claim 1, characterized in that the coaxial dielectric resonator is formed of: (3) Claims 1 or 2, characterized in that the dielectric constant of the second dielectric material is equal to or greater than that of the first dielectric material. The coaxial dielectric resonator described. (4) A coaxial type dielectric according to claim 1 or 2, characterized in that the axial end face of the second dielectric material projects from the open end face of the first dielectric material. body resonator.