JPS60137101A - dielectric filter - Google Patents

Abstract

PURPOSE:To obtain a dielectric filter of stable quality which is manufactured and assembled easily by molding projection parts at the lower end part of a main housing body in one body, and shortcircuiting lower end parts of dielectric coaxial resonance elements to tops of the projection parts. CONSTITUTION:Circular projection parts 41a-41d are provided at the lower end part of the main housing body 1, and lower end parts of dielectric coaxial resonance elements 2a-2d are shortcircuited to tops of the projection parts 41a-41d with a fixing agent 42 such as cream solder and conductive paste. The projection parts 41a-41d are formed in one body by a press machine. Consequently, the dielectric filter of stable quality which is manufactured and assembled easily is obtained.

Description

[Detailed description of the invention] Industrial applications The present invention relates to a dielectric filter.

Configuration of Conventional Example and Its Problems A conventional dielectric filter will be described below with reference to the drawings.

Fig. 1 is a sectional view of a dielectric filter consisting of four stages of dielectric coaxial resonant elements in a sheet metal case, which is considered as a conventional example, Fig. 2 is a sectional view taken along the line A-A' in Fig. 1, and Fig. 3 is a dielectric FIG. 3 shows a perspective view of a body-coaxial resonant element. In Figures 1, 2, and 3, 1 is a body made of bent thin sheet metal.
d is a dielectric coaxial resonant element as shown in Fig. 3, in particular, 2a is a dielectric coaxial resonant element on the input side, and 2d is an output side dielectric coaxial resonant element, which is longer than the dielectric coaxial resonant elements 2b and 2c between one stage. is getting shorter. This is because the coupling capacitance between the dielectric coaxial resonant element 2a on the input side and the dielectric coaxial resonant element 2d on the output side is larger than that of the dielectric coaxial resonant elements 2b and 2c between the legs, so changing the length allows coupling. The common frequency fO is matched by changing the capacitance. 3 is an inner conductor, 4 (d is an outer conductor, and the surface of the dielectric 6 is coated with a conductive paste or copper plating with excellent high-frequency conductivity. 6 is a bonding board that connects each adjacent dielectric coaxial resonant element. Light-transmissive electrical coupling between the two is performed using an 8-degree loss circuit formed on a dielectric substrate.

ya, 7b, 7C, yd are central conductors made of metal, and fixing agents 8a, s such as cream solder or conductive paste are applied to the inner conductor 3 of each dielectric resonant element together with the bonding substrate 6.
0 9 a + 9b fixed at b , 8c , sa
is a fixing agent such as cream solder or conductive paste that fixes the cylindrical body 1, the side plate 10 made of a metal plate, and the dielectric coaxial resonant elements 2a, 2b, 2c, and 2d. 1
Numerals 1a, 11b, 11c, and 11d are tuning screws made of metal, which are attached to tuning screws 12 made of metal to adjust the frequency of each resonant element. 13a is an input side connector, and 13b is an output side connector. 14
is a bent portion at the lower end of the housing body 1, which is bent with an appropriate bending radius.

A method for manufacturing the dielectric filter constructed as described below will be described below.

First, the inside of the housing body 1 and the dielectric coaxial resonant elements 2a, 2b
, 2G, and 2d are applied with a fixing agent 9a such as cream solder or conductive paste. Next, dielectric coaxial resonant elements 2a+2b+2c.

Fixing agents 8a, sb, 8c, and sa such as cream solder or conductive paste are applied to the inner conductor 3 of 2d.

Next, the center conductor 7a is inserted into the hole of the coupling board 6 corresponding to the center of each dielectric coaxial resonant element 2a12b, 2c, 2d.
, 7b, 7c, and 7d (with smaller outer diameters), and dielectric coaxial resonant elements 2a', 2b are attached to the tips.
, 2c, and 2d are mounted in this order so that the surface of the dielectric 3 faces the bonding substrate 6, and then the entire block is mounted inside the casing body 1. Next, the dielectric coaxial resonant element 2a,
2b.

A fixing agent 9b such as cream solder or conductive paste is applied to the side of the dielectric coaxial resonator where 2c and 2d are in contact with the side plate 10. Next, after attaching the side plate 10, the whole is fixed by heating in a furnace. Next, after fixing the input side connector 13a and the output side connector 13b to the side surface of the open end of the housing body 1 with solder, etc., the input side connector 13a and the output side connector 1
The tip terminal of 3b and each terminal on the input/output side of the bonding board 6 are connected.

Next, the tuning screws 11a and 11b.

After mounting 11C and 11d on the tuning screw plate 12, the tuning screw plate 12 is fixed to the open end of the housing body 1. The dielectric filter can be formed relatively easily by fixing by soldering, conductive paste, screws, or the like. However, in the above configuration, since the lengths of the dielectric coaxial resonant elements 2a and 2d on the input and output sides are shorter than those of the dielectric coaxial resonant elements 2b and 2C between the stages, the coupling substrate 6 may be bent. The center conductor 7a is bent and deformed.

7 b l 7 c t 7 d is attached to the surface of the dielectric 5 of each dielectric coaxial resonant element.

In such a state, troubles such as damage to the bonding substrate 6 and peeling off of the thin copper of the bonding pattern formed on the surface of the bonding substrate occur, leading to a decrease in productivity. Also, the dielectric coaxial resonant element 2a is attached to the shoulder of the bent portion 14 at the lower end of the housing body 1.
, 2b, 2. The periphery of the lower ends of c and 2d is raised, and the shape of the housing body 1 widens from the upper end to the lower end, resulting in unacceptable errors in manufacturing, resulting in poor yields. However, it has the disadvantage that it is unsightly in shape and difficult to install in equipment.

OBJECTS OF THE INVENTION The present invention eliminates the above-mentioned drawbacks of the prior art, and aims to provide a dielectric filter that is easy to manufacture and assemble and has stable quality.

Structure of the Invention In order to achieve the above object, the filter of the present invention has a convex portion formed integrally with the lower end of the casing, and a dielectric resonant element is mounted on the convex portion.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 4 shows a cross section of a dielectric filter composed of four stages of dielectric coaxial resonant elements according to an embodiment of the present invention.
It shows a cross section taken along the line A-A' in the figure.

4 and 5, the difference from the conventional configuration shown in FIGS. 1 to 3 is that a circular convex portion 41
a, 41b, 41C, and 41d, this convex portion 4
Dielectric resonant elements 2'a, 2b on 1a to 41d
The lower end of + 20 + 2 d is short-circuited by a fixing agent 42 such as cream solder or conductive paste. Convex portion 41
a, 41b, 41c, and 41d are integrally formed by a press machine. Further, the heights of the convex portions 41b and 41c may be the same as long as they are equal to or greater than the bending radius of the bent portion 16 at the lower end of the housing body 1. - The heights of the convex portions 4゛1a and 41d are the same and on the same side of the dielectric (the height of the convex ↑ SIS 4 l b, 41 C is matched to the difference in height between the resonant elements 2a, 2d and 2b, 2C) Therefore, the dielectric coaxial resonant elements 2a, 2b, 2c
, 2d and convex portions 41 a , 41 b , 41 c
, 41 d, the total height of each resonator is - than the apparent height of each resonator. Convex portions 41a141b, 41c, 4
The shape of 1d is not limited to a circle but may be any other shape.
Since the heights of 1b41c are the same and they are adjacent to each other, the shape of the convex portions may be formed integrally as shown in FIG.

According to the above configuration, the dielectric elements 1'l11, 2a, 2b, 2c, 2 are provided at the lower end of the entire body 1.
Convex portions 41a, 41b, 41c, and 41d are provided corresponding to the convex portions Ffli, and the dielectric coaxial resonant element 2a is directly mounted on the convex portions Ffli.
, '2b', '2c' and '2d' are short-circuited at their lower ends, so manufacturing and assembly is easy and quality is stable.

As described above, the present invention provides a convex portion at the lower end of the housing body, and short-circuits the lower end of the dielectric resonant element onto the convex portion, thereby stabilizing the quality. Furthermore, it is possible to obtain a product with easy assembly work and low cost, which has great effects.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of a dielectric filter considered as a conventional example, Fig. 2 is a sectional view taken along line A'-A' in Fig. 1, Fig. 3 is a perspective view of a dielectric coaxial resonant element, and Fig. 4 is a sectional view of a dielectric filter considered as a conventional example. A sectional view of a dielectric filter according to an embodiment of the present invention, FIG. 5 is A of FIG.
-A' line sectional view and FIG. 6 are perspective views of essential parts in another embodiment of the present invention. 1... Housing body, 2a, 2b, 2c, 2
d...Dielectric coaxial resonant element, 3...Inner conductor-
4... Outer conductor, 5... Dielectric, 6...
...Binding substrates, 7a, 7b. 7 c, 7 d-...center conductor, sa+sb
+sc+sa. 9a, 9b...Fixing agent, 10...Side plate, 11
a. 11b, 11c, 11d...Tuning screw, 12...Screw plate, 13a...
...Output fl+! 1 Connector 13b... Output side connector, 14... Lower end bent part -418
,, 41b, 41c, 41d...Convex portion, 42...Fixing agent. Name of agent: Patent attorney Toshio Nakao (1st person)
Figure Figure 2 q @4 Figure 5 Figure 6 Figure 4 (d 1Ilb, 4/(, ”0-

Claims (1)

[Claims] A dielectric filter in which at least two types of protrusions are provided at the lower end of a housing, and the lower ends of at least one dielectric coaxial resonant element are short-circuited on the protrusions.