JPS63283201A - Integrally molded type high frequency filter - Google Patents

Abstract

PURPOSE:To miniaturize a component without reducing an interval between resonators, by inclining a line connecting adjacent through holes for the side of a dielectric block in a longitudinal direction in an integrally molded type high frequency filter consisting of the resonators by connecting them with each other. CONSTITUTION:The lines connecting the adjacent resonators 7a and 7b, 7b and 7c, and 7c and 7d are inclined against the side 2a of the dielectric block 2 in the longitudinal direction. In other words, they are arranged on the polygonal point of the polygonal line L2 in a zigzag shape observing from a flat plane. The polygonal line L2 is desired to be set so that an internal angle theta formed between a part connecting the resonators 7a to 7b and the part connecting the 7b to the 7c, and the internal angle formed between the part connecting the 7b to the 7c and the part connecting the 7c to the 7d can be set at 120-60 deg.. In such a way, it is possible to reduce the size of the dielectric block in the longitudinal direction by (l) compared with a case where the resonators of four stages are arranged on a straight line, and thereby, the component can be miniaturized by that size.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to an integrally molded high frequency filter used in high frequencies, for example, in the several 100 MHz range, and particularly relates to a resonator arrangement that allows miniaturization without lowering the Q. Regarding structure.

[Conventional technology]

2. Description of the Related Art Conventionally, there is a one-piece high-frequency filter that functions as a band-pass filter, as shown in FIG. 5, for example.

This integrally molded high frequency filter 15 has four through holes 17 formed in a rectangular parallelepiped dielectric block 16 on a straight line L+ parallel to the longitudinal side 16a of the block 16, and the inner periphery of each through hole 17. A conductive film is formed on each of the surface and the outer surface of the dielectric block 16, and one end of the good conductive film is short-circuited to configure four stages of λ/4 wavelength resonators 18, and between adjacent resonators 18. A coupling cavity 19 is provided in the.

The integrally molded high frequency filter 16 is incorporated into a circuit of a communication device, for example, and has a function of selecting a specific high frequency.

[Problem that the invention seeks to solve]

However, the above conventional integrally molded high frequency filter 1
5, each time the number of stages of the resonators 18 is increased, the lengthwise dimension of the dielectric block 16 becomes longer, which increases the size of the components, and there is a problem that it cannot cope with the miniaturization and thinning of electronic devices in recent years.

Here, for example, it is possible to prevent the increase in size by narrowing the distance between adjacent resonators 18, but in this case, if they are brought too close together, the Q will drop and the characteristics will deteriorate, so the distance between the resonators 18 can be reduced. There are limits to how you can do it.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide an integrally molded high-frequency filter that enables miniaturization of components without narrowing the spacing between resonators.

[Means for solving problems]

The present invention forms a plurality of through holes in a dielectric block in parallel, and forms a conductive film on the inner surface of each through hole and the outer surface of the dielectric block to form a plurality of resonators. The integrally molded high frequency filter is characterized in that the line connecting the adjacent through-holes is inclined with respect to the longitudinal side of the dielectric block.

Here, being inclined with respect to the longitudinal side of the dielectric block of the present invention means that if there are two resonators, for example, they are arranged diagonally, and if there are three or more resonators, it means that they are arranged diagonally. means that each resonator is arranged on a break point of a zigzag-shaped polygonal line.

[Effect]

According to the integrally molded high-frequency filter according to the present invention, the line connecting adjacent through holes is inclined with respect to the longitudinal side of the body block. In addition, when there are three or more holes, they are arranged on a zigzag bent line, so the longitudinal dimension of the dielectric block can be reduced while ensuring the necessary spacing between the through holes.
As a result, the components can be made smaller while avoiding deterioration of Q characteristics.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

1 to 3 show an integrally molded high frequency filter according to an embodiment of the present invention. First, in this embodiment, the basic structure of the filter will be explained.

In the figure, 1 is an integrally molded high frequency filter. 2
is a rectangular parallelepiped dielectric block made of ceramic dielectric, and the block 2 has four through holes 3a, 3b,
3c and 3d are formed in parallel with a certain interval,
The inner circumferential surface of each of the through holes 31 to 3d is coated with a conductive film 4 formed by baking and fixing Ag in the form of a single film. Also, on the west side and bottom of the dielectric block 2,
Conductive film formed by baking g.5. A short-circuit conductive film 6 is formed. This short-circuiting conductive film 6 is for short-circuiting the conductive film 4.5 to generate a resonance mode of λ/4 wavelength.
c, 7d are configured.

Further, the adjacent resonators 7a and 7 of the dielectric block 2
Between b, 7b and 7c, and 7c and 7d, there is a blank W for coupling.
:I8 is formed penetratingly, and no conductive film is formed on the inner peripheral surface of the cavity 8.

This cavity 8 has a rectangular cross section, and depending on its shape 9 dimensions, each resonator 7a, 7b, 7c, ? It depends on the degree of coupling between d. Although not shown, the dielectric block 2 is provided with an input terminal and an output terminal.

In this embodiment, each of the adjacent resonators 7a and 7b
, 7b and 7c, and 7c and 7d are inclined with respect to the longitudinal side 2a of the dielectric block 2.

That is, as shown in FIG. 2, each resonator 7a is
, 7b, 7c, and 7d are arranged on the bending point of the zigzag-shaped bending NIAL8. This fold HLm is the resonator 7
So that the internal angle θ between the part connecting a and 7b and the part connecting 7b and 7c, and the internal angle θ between the part connecting 7b and 70 and the part connecting 7c and 7d are 120 degrees to 60 degrees. In other words, if the internal angle θ is expanded to 120 degrees or more, the length of the dielectric block will not be much different from the case where the resonator is arranged above the straight line, and on the other hand, this internal angle θ If it is narrowed to 60 degrees or less, it may jump over adjacent resonators and couple with other resonators, causing characteristic deterioration. Therefore, it is desirable that the internal angle θ be within the range of 60 to 120 degrees.

Next, the effects of this embodiment will be explained.

According to the integrally molded high frequency filter 1 having four stages of resonators 7a, 7b, 7c, and 7d of this embodiment, each resonator 7a
7b, 7b and 7c, and 7c and 7d are inclined with respect to the side 2a of the dielectric block 2, that is, they are bent in a zigzag shape &iL Compared to the case where four stages of resonators are arranged,
The longitudinal dimension of the dielectric block can be reduced by l, and the components can be made smaller accordingly. Further, in this case, since the distances between the resonators 7a and 7b, 7b and 7C, and 7C and 7d are the same as in the conventional case, the characteristics of the high frequency filter 1 are not impaired. This makes it possible to respond to the trend toward smaller and thinner electronic devices in recent years.

In addition, although the above embodiment has been explained by taking as an example the integrally molded high frequency filter 1 having four stages of resonators, the present invention can of course be applied to high frequency filters having other stages.
For example, in the five-stage bandpass filter shown in FIG. 4, each resonator ? a.

By arranging 7b, 7c, 7d, and 7e in a zigzag pattern, the same effect as in the above embodiment can be obtained.

In this case, the polarized coupling electrode 1.0 may be formed at the center of the line connecting the second resonator 7b and the fourth resonator 7d to couple the resonators 7b and 7d together. The attenuation pole (
This also has the effect of making it possible to create a filter with better attenuation characteristics.

Further, in the above embodiment, a filter having a coupling cavity was described, but the scope of application of the present invention is not limited to a filter having this structure. It can also be applied to a stepped resonator or an integrally molded high frequency filter in which an electrode film is formed on the open surface of a dielectric block.

〔Effect of the invention〕

As described above, according to the integrally molded high frequency filter according to the present invention, the line connecting adjacent through holes is inclined with respect to the longitudinal side of the dielectric block, so that the interval between the through holes can be changed. This has the effect of reducing the longitudinal dimension of the dielectric block without sacrificing Q characteristics.

[Brief explanation of drawings]

1 to 3 show an integrally molded high-frequency filter according to an embodiment of the present invention, FIG. 1 is a perspective view thereof, FIG. 2 is a plan view thereof, and FIG. 3 is a line taken along the line ■-■ in FIG. A sectional view, FIG. 4 is a plan view of the case where it is applicable to a five-stage integrally molded high frequency filter, and FIG. 5 is a plan view showing a conventional integrally molded high frequency filter. In the figure, 1 is an integrally molded high-frequency filter, 2 is a dielectric block, 2a is a longitudinal side, 3a to 3d are through holes, 4.5 is a conductive film, 7a to 7d are resonators, and L8 is a through hole. This is the line that connects the holes. Patent applicant Murata Manufacturing Co., Ltd. Representative Patent attorney Tsutomu Shimofu Figure 1 Figure 3

Claims (1)

[Claims] (1) At least two through holes are formed in a dielectric block in parallel, and a conductive film is formed on the inner surface of each through hole and the outer surface of the dielectric block to form at least a pair of resonators, and the resonator The integrally molded high frequency filter is characterized in that a line connecting the adjacent through holes is inclined with respect to a longitudinal side of the dielectric block. .