JPH0352009Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention relates to a dielectric resonator used in high frequency bands such as microwaves. The present invention also relates to a dielectric resonator that is formed of a highly compressible material and that is brought into close contact with the outer surface of the resonator body due to its elasticity.

[Prior Art] Resonators using dielectric ceramics such as barium titanate have the advantage of having low loss, high Q, and high inductivity, allowing for miniaturization, and are used in microelectronic applications such as car telephones and satellite communications. It is widely used for frequency selection, etc. for wave bands.

Conventional techniques related to dielectric resonators include one-stage structure in which a single resonator hole is formed in the center of a dielectric block, and one in which a plurality of resonator holes are formed at a predetermined interval in the longitudinal direction of a rectangular parallelepiped dielectric block. There are those with a multi-stage structure in which resonator holes and coupler holes are provided alternately. In either case, a conductor layer is formed on at least a portion of the outer surface of the dielectric block and on the inner surface of the resonator hole by metallization or the like.

In the prior art, as shown in FIG. 4, such a dielectric resonator main body 10 is housed inside a metal case 12 made of die-cast aluminum or the like, and a metal cover 14 made of sheet metal processing or the like is attached. The configuration is adopted. In this case, it is necessary to establish an electrical connection (ground connection) between the conductor layer formed on the outer surface of the dielectric resonator body 10 and the metal case 12, and various structures have been adopted for this purpose.

For example, FIG. 1A shows an example in which a U-shaped ground plate 16 is used to cover three sides of the dielectric resonator body 10. This ground 16 is in close contact with the outer surface of the dielectric resonator main body 10, and a number of U-shaped holes are formed on the side surface, and the tongue portion 18 surrounded by the U-shaped holes is directed outward. The structure is such that it is brought into contact with the metal case 12 due to its spring properties.

FIG. 2B shows an example in which the dielectric resonator main body 10 has a circular cross section. A flat ground plate 20 is placed on the top, and a tongue portion 22 protruding both upward and downward from the ground plate 20 is brought into contact with both the dielectric resonator main body 10 and the metal cover 14.

Further, FIG. 1C shows a structure in which the dielectric resonator main body 10 and the metal case 14 are fixed with solder or a conductive adhesive 24.

[Problems to be Solved by the Invention] However, the above-mentioned conventional technology has drawbacks such as the large number of parts, making it difficult to assemble, and the ground connection not necessarily being sufficiently reliable.

An object of the present invention is to provide a dielectric resonator which eliminates the above-mentioned drawbacks of the prior art, has a simple structure, and can ensure reliable ground contact.

[Means for Solving the Problems] The present invention, which can achieve the above objectives, uses a metal case that has conductivity, elasticity, and compressibility as a case for housing the dielectric resonator body. The dielectric resonator is made of a rich material, and the dielectric resonator body is fitted into the case, and its elasticity allows it to come into close contact with the outer surface of the dielectric resonator body.

A suitable material for the case is, for example, low-resistance conductive rubber. If the case is soft and lacks mechanical strength (shape retention), it is also effective to use a metal reinforcing plate or the like.

[Operation] By utilizing the elasticity and compressibility of the case, the dielectric resonator main body is fitted into the case. If the inner surface of the case is designed to be slightly smaller than the outer surface of the dielectric resonator body, when the dielectric resonator body is fitted into the case, the elastic force of the case itself will cause the inner surface to touch the outer surface of the dielectric resonator body. This makes it possible to fix the dielectric resonator body without using any adhesive or the like. In other words, there is no need for a member interposed between the dielectric resonator body and the case as in the prior art.

Furthermore, since the two are in complete surface contact, electrical continuity is also ensured. For example, if conductive rubber is used as the case, it can function as a ground because it has a low resistance (for example, about 10 ^-3 Ω·cm or less).

[Embodiment] FIG. 1 is a sectional view showing an embodiment of a dielectric resonator according to the present invention, and FIG. 2 is an exploded perspective view thereof.

The dielectric resonator main body 30 consists of a substantially rectangular parallelepiped dielectric block 32 made of a sintered body of a high dielectric constant ceramic material such as barium titanate, and has four resonator holes 34 spaced apart in the longitudinal direction. are formed, a coupler hole 36 is provided between the resonator holes 34, and the dielectric block 32
A conductor layer 38 is formed by metallization on all sides and bottom surfaces of the resonator hole 34 and on the inner surface of the resonator hole 34.

In FIG. 2, portions where the dielectric base is exposed without being metallized are shown with fine dots. Also, the conductor layer 3
8 is drawn to have a considerable thickness for ease of understanding, but in reality it is extremely thin, formed by baking silver paste, etc.

Coupling capacitors 3 are placed on the open ends of the resonator holes located at both ends of the dielectric block 32.
9 and is connected to an external circuit via this coupling capacitor 39.

The dielectric resonator main body 30 is housed in a case 40 made of a material that is highly conductive, elastic, and compressible. This case 40 is integrally molded from highly conductive silicone rubber or the like. In the embodiment shown in FIG. 1, the shape is slightly narrower than the width of the dielectric resonator body 30 to be inserted. When the dielectric resonator main body 30 is pushed into the case, the case 40 is elastic and compressible, so it expands slightly and is pushed in, bringing the two into close contact, achieving both mechanical coupling and electrical continuity at once. It turns out. Finally, the dielectric resonator is assembled by covering it with a metal cover 42 having, for example, input/output terminals (not shown) and gluing it with a conductive adhesive.

The case structure, which is made of a material that is highly conductive, elastic, and compressible, can be modified in various ways. An example is shown in FIG. The embodiment A shown in FIG. 1 is basically the same as the embodiment shown in FIG. Since the case 40 is made of an elastic material, it may be deformed depending on the material and shape (dimensions). In such a case, a metal reinforcing plate 44 is installed at the bottom of the case.
Just insert and reinforce it.

If the dielectric resonator main body 30 to be accommodated has a circular cross section, for example, a recess 46 of a shape corresponding to the recess 46 is formed in advance on the inner wall of the case 40, and the recess 46 is fitted and fixed therein.
In this way, even if the dielectric resonator main body has a special cross-sectional shape, reliable conduction can be achieved through surface contact.

In the embodiment shown in Figure C, a groove 48 is formed in the inner bottom of the case 40 to make the side wall of the case easier to bend. As a result, the dielectric resonator body 30
can be pushed into the inner bottom of the case 40 reliably and easily.

Note that as the material of the case, it is also possible to use conductive soft plastics in addition to conductive rubber.

[Effects of the invention] As mentioned above, the present invention uses a material with high conductivity, elasticity, and compressibility as a case for housing the dielectric resonator body, and its elasticity allows it to be tightly attached to the dielectric resonator body. Since it is configured to It has excellent effects such as being reliable.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing one embodiment of a dielectric resonator according to the present invention, FIG. 2 is an exploded perspective view thereof, and FIGS. 3 A, B, and C are sectional views showing other embodiments of the present invention. ,
FIGS. 4A, B, and C are sectional views showing the prior art, respectively. 30... Dielectric resonator body, 40... Case,
42...metal cover, 44...metal reinforcing plate,
46... recessed portion, 48... recessed groove.

Claims (1)

[Scope of utility model registration request] A dielectric resonator body is housed in a conductive case, and the case is made of a material that is highly conductive, elastic, and compressible, and the dielectric resonator body is housed within the case. A dielectric resonator characterized in that the inner surface of the case is fitted into the outer surface of the dielectric resonator body due to its elasticity.