JPS61139102A - Layer-built dielectric resonator - Google Patents

Abstract

PURPOSE:To improve the temperature stability and to reduce the reduction of a non-load Q value of a resonator itself by storing and fixing plural laminated dielectric resonator units in a storage case consisting of a resin material whose coefficient of thermal expansion is equal to or approximates that of dielectric resonator units and dielectric loss tandelta is small. CONSTITUTION:Resonator units 1... are molded articles consisting of a titanium oxide ceramic dielectric and are laminated in the axial direction and are stored in a storage case 2 in this state. The storage case 2 is formed into a thin bottomed cylindrical shape and consists of the resin material such as a 'Teflon(R)' resin which has the relatively small dielectric loss tandelta and has a coefficient of thermal expansion equal to or approximating that of materials of resonator units 1.... Each resonator unit 1 is stored in the storage case 2 so that its peripheral wall is brought closely into contact with the inside wall surface of the case 2, and a cap 3 consisting of the same materials as the case 2 is covered on the open end face of the case 2 after resonator units 1... are stored there. The storage case 2 where resonator units 1... are set is set in a metallic conductor case 4.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a stacked dielectric resonator used, for example, as a filter.

<Prior Art> Generally, as this type of dielectric resonator, there is one in which a resonator unit is constructed of, for example, a cylindrical or cylindrical dielectric block. In this case, the occurrence of spurious in the frequency range near the frequency of the desired resonance mode is not desirable in terms of obtaining good resonance characteristics.

For this reason, conventionally, for example, TEo1 is used as a resonance mode.
When using the t-mode, as shown in Figure 3, short cylinders (or short cylinders) each act as a resonator.
A plurality of dielectric resonator units... are prepared, and these resonator units... are stacked in the axial direction so that the whole acts as one stacked dielectric resonator, and each The periphery of the resonator unit is shielded with a conductor case 4 to move spurious to a high frequency range and improve its characteristics.

<Problems to be Solved by the Invention> Incidentally, in such a multilayer resonator, in order to stack the dielectric resonator units and mechanically couple them to each other, for example, epoxy is used. A type of resin adhesive 8 is used. However, in this case, the adhesive strength of the adhesive 8 deteriorates due to a sudden change in ambient temperature, and as a result, the mechanical and electrical properties of the resonator itself deteriorate. adversely affects physical characteristics. Further, when an epoxy resin is used as the adhesive 8, the dielectric loss tan δ of the resin is sadly large compared to that of the resonator. Therefore, there is a problem in that the energy loss of the resonant system at the joints between the resonator units by the adhesive 8 is large, leading to a decrease in the no-load Q value of the resonators themselves.

In view of these conventional problems, the present invention seeks to provide a dielectric resonator with good temperature stability and excellent resonance characteristics.

Means for Solving the Problems> In order to achieve the above object, the present invention stores and fixes a plurality of stacked dielectric resonator units in a storage case, and also sets the storage case to a dielectric resonator. The thermal expansion coefficient is the same or similar to that of the device unit, and the dielectric loss tan
It is characterized by being made of a resin material with a small δ.

<Example> Hereinafter, the present invention will be described in detail based on an example shown in the drawings.

FIG. 1 is a longitudinal sectional front view of this embodiment, and FIG. 2 is a half-cut perspective view. In these figures, the stacked dielectric resonator of this embodiment has, for example, TEl, lt as resonance modes.
mode, and includes a plurality (three in the figure) of dielectric resonator units I... These resonator units 1 are molded products made of titanium oxide (Tilt) based ceramic dielectric, and are housed in a storage case 2 in a stacked state in the axial direction.

This storage case 2 is formed into a thin-walled cylindrical shape with a bottom of approximately 1 mm in wall thickness, has a relatively small dielectric loss tan δ, and has a thermal expansion coefficient equivalent to or similar to the material of the resonator unit 1. It is made of a resin material such as Teflon resin (trade name). Each resonator unit described in FJ is assembled with its peripheral wall in close contact with the inner wall surface of the storage case 2, and after being stored, a cap 3 made of the same material as the case 2 is placed on the open end surface of the storage case 2. covered. Note that when attaching this cap 3 to the case, an epoxy resin adhesive with a large dielectric loss tan δ may be used, but in this case, the amount of the adhesive used is extremely small, and the resonator It has almost no effect on its own resonance characteristics.

Storage case 2 in which each resonator unit 1 is incorporated
is incorporated into a metal conductor case 4. The conductor case 4 is formed in a cylindrical shape, and a dielectric substrate 5 of low dielectric constant, such as forsterite, which has little influence on the resonance system, is disposed at the bottom thereof. The storage case 2 is fixed on the dielectric substrate 5 and is electrically shielded by the conductor case 4. Note that the reference numeral 6 indicates a lead terminal for output, which is pulled out from the conductor case 4.

Note that the shape of the conductor case 4 is not necessarily limited to a cylindrical shape as long as it shields the periphery of the dielectric resonator unit.

Further, each dielectric resonator unit . . . may have a cylindrical shape with a through hole 7 provided in the center, as shown by the imaginary line in FIG.

<Effects of the Invention> As described above, according to the present invention, first, a plurality of stacked dielectric resonator units are stored and fixed in a storage case. Therefore, since there is no need to bond and fix the resonator units with adhesive, it is possible to eliminate the adverse effects of adhesive on the mechanical and electrical characteristics of the resonator itself, unlike in the past. In addition, since the storage case is made of a resin material that has the same or similar coefficient of thermal expansion as the dielectric resonator unit and has a small dielectric loss tan δ, the dielectric resonator unit can be stored even if the ambient temperature changes. Not only can it be well fixed and held within the case, but also the no-load Q value of the resonance system can be maintained at a high Q value.

[Brief explanation of the drawing]

1 and 2 show an embodiment of the present invention. FIG. 1 is a longitudinal sectional front view of this embodiment, FIG. 2 is a half-cut perspective view, and FIG. 3 is a longitudinal sectional front view of a conventional example. 1. Dielectric resonator unit, 2. Storage case.

Claims (2)

[Claims] (1) In a stacked dielectric resonator formed by stacking a plurality of dielectric resonator units, the stacked plurality of dielectric resonator units are housed and fixed in a storage case, and the storage case is A multilayer dielectric resonator comprising a resin material having a thermal expansion coefficient equal to or similar to that of a resonator unit and a small dielectric loss tan δ. (2) The multilayer dielectric resonator according to claim 1, wherein the storage case is made of Teflon resin (trade name).