JPH01316002A - Triplate type strip line filter - Google Patents

Abstract

PURPOSE:To adjust the deteriorated characteristic and to improve the yield by arranging 1st and 2nd dielectric bases in a way that the resonance electrodes are opposed to each other and forming a characteristic adjustment electrode relating to the resonance electrode to one major face or both major faces of a 3rd dielectric base which is clipped between both the 1st and 2nd bases. CONSTITUTION:The 1st and 2nd dielectric bases 12, 14 of a triplate type strip line filter are arranged in a way that the resonance electrodes 20, 22 are opposed to each other. The 3rd dielectric base 24 is clipped between the electrodes 20, 22. In this case, the dielectric base 24 is positioned so that the characteristic adjusting electrode 26 and the electrodes 20, 22 are opposed when they are overlapped at the post process. Then they are overlapped so that the end faces of the 1st to 3rd bases 12, 14 and 24 are mated, and each long and thin electrode constituting the resonance frequency adjusting electrode 28 and a coupling coefficient adjusting electrode 30 formed to both the faces of the 3rd dielectric base 24 is connected to a ground electrode 16 to apply adjustment as required.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a triplate-type strip line filter, and in particular, to a tri-plate type strip line filter that includes first and second dielectric substrates each having a resonant electrode formed on one main surface thereof. The respective resonant electrodes are arranged to face each other, and the first and second resonant electrodes are arranged so as to face each other.
The present invention relates to a triplate type strip line filter in which a third dielectric substrate is sandwiched between two dielectric substrates.

[Prior art]

This kind of triplate stripline filter is
This is already well known□.

[Problem that the invention seeks to solve]

In such a triplate type stripline filter, the resonant frequency and coupling coefficient of the stripline resonator configured on the two upper and lower dielectric substrates are adjusted on each dielectric substrate, and then the three dielectric The final characteristics were determined by overlapping the substrates. However, with this conventional method, when stacking the dielectric substrates, dimensional deviations occur and the desired characteristics cannot be obtained.On the other hand, there is no means to make adjustments after stacking the dielectric substrates, so in such cases, it is difficult to obtain the desired characteristics. It has been treated as a good product. Therefore, with the conventional technology, the yield was not very good.7 Therefore, the main purpose of the present invention is to
An object of the present invention is to provide a triplate type stripline filter.

[Means for solving problems]

In the present invention, first and second dielectric substrates each having a resonant electrode formed on one main surface thereof are arranged so that the respective resonant electrodes face each other, and a gap between the first and second dielectric substrates is provided. In the I-ribrate type strip line filter, which is stacked with a third dielectric substrate sandwiched between the two,
A strip line filter, characterized in that a characteristic adjustment electrode is formed on one or both main surfaces of the third dielectric substrate at a position related to the resonant electrode and is connected to ground as necessary. be.

[Effect]

Characteristic adjustment electrodes are formed on one or both main surfaces of the third dielectric substrate at positions related to the resonance electrodes formed on the first and second dielectric substrates. This characteristic adjustment electrode is connected to the ground electrode in advance, and by cutting off the connection between the characteristic adjustment electrode and the earth electrode at an appropriate portion as necessary, the capacitance is mainly changed to increase the resonant frequency and Adjust the coupling coefficient.

However, conversely, the same effect can be achieved by connecting an appropriate characteristic adjustment electrode to the ground electrode as required.

〔Effect of the invention〕

According to this invention, the resonant frequency and coupling coefficient can be adjusted after stacking three dielectric substrates, so that the characteristics do not change due to dimensional deviations when stacking the dielectric substrates. can also fix it. Therefore, according to the present invention, desired characteristics can be reliably obtained, and as a result, the non-defective product rate (yield) can be improved and costs can be reduced.

The above objects, other objects, features and advantages of the present invention will become more apparent from the following detailed description of embodiments with reference to the drawings.

〔Example] FIG. 1 is an exploded perspective view showing an embodiment of the present invention.

The stripline filter 10 includes a first dielectric substrate 1
2 and a second dielectric substrate 14. The first dielectric substrate 12 and the second dielectric substrate 14 are made of a high dielectric constant material such as ceramic and are formed into rectangular plate shapes, for example.

Ground electrodes 16 are formed on the lower main surface and side surfaces of the first dielectric substrate 12 and the upper main surface and side surfaces of the second dielectric substrate 14, respectively. Furthermore, the first dielectric substrate 12
A comb-shaped resonant electrode 18 is provided on the upper main surface and the lower main surface of the second dielectric substrate 14 with a gap 20 between them, and one end of each is connected to the ground electrode 16.
is formed. Therefore, the resonant electrode 18 of this embodiment
is formed as λ/4. The input/output electrode 22a is connected to each common connection part of the resonant electrode 18.
and 22b are formed.

The third dielectric substrate 24 is formed into a rectangular plate shape like the first dielectric substrate 12 and the second dielectric substrate 14, but its thickness is approximately 1/2, and It also has a low dielectric constant. Therefore, the third dielectric substrate 24 may be made of resin, for example. On both main surfaces of the third dielectric substrate 24, there are characteristic adjustment electrodes 2 at positions related to the resonance electrodes 18.
6 is formed.

The characteristic adjustment electrode 26 includes a resonance frequency adjustment electrode 28 and a coupling coefficient adjustment electrode 30. As shown in FIG. 2, the resonance frequency adjustment electrode 28 is formed by a plurality of (three in the embodiment) elongated electrodes facing the free end of the resonance electrode 18 indicated by the dotted line. Coupling coefficient adjustment electrode 3
0 is formed by a plurality (two in the example) of elongated electrodes that extend into the spacing 20 of the resonant electrodes 18 . In this way, the characteristic adjustment electrode 26 is arranged so that the resonance frequency adjustment electrode 28 and the coupling coefficient adjustment electrode 30 are alternately continuous
is formed on the third dielectric substrate 24. Note that the number of elongated electrodes forming the resonance frequency adjustment electrode 28 and the coupling coefficient adjustment electrode 30 may be one if possible.

When overlapping, first, the first dielectric substrate 12 and the second dielectric substrate 14 are arranged so that their respective resonance electrodes 20 and 22 face each other. A third dielectric substrate 24 is then sandwiched between the resonant electrodes 20 and 22.

At this time, as shown in FIG. 2, the third dielectric substrate 24 is positioned so that the characteristic adjustment electrode 26 and the resonant electrodes 20 and 22 face each other when they are overlapped in a subsequent step. Then, the first to third dielectric substrates 12.1
4 and 24 so that their end faces are flush with each other. At this time, each of the elongated electrodes constituting the resonant frequency adjustment electrode 28 and the coupling coefficient adjustment electrode 30 formed on both main surfaces of the third dielectric substrate 24 is
As shown in FIG. 3, it is connected to the ground electrode 16 by, for example, baking or soldering.

When adjusting the resonant frequency, the connecting portion 32 between the resonant frequency adjusting electrode 28 and the ground electrode 16 is cut off as necessary using a router or the like.
The resonant frequency adjustment electrode 28 is separated from the ground electrode 16. Depending on how many elongated electrodes are separated, the value of the capacitance formed on the free end (open end) side of the resonant electrode 18 by the resonant frequency adjustment electrode 28 differs. By appropriately setting the number, a desired resonant frequency can be obtained.

Similarly, the coupling coefficient adjustment electrode 30 and the earth electrode 16
The coupling coefficient can be adjusted by cutting off the connecting portion 34 between the resonant electrode 18 and the resonant electrode 18 as necessary to change the capacitance between the resonant electrodes 18.

[Brief explanation of the drawing]

FIG. 1 is an illustrative view showing an embodiment of the present invention. FIG. 2 is an illustrative diagram showing the positional relationship between the characteristic adjustment electrode and the resonant electrode. FIG. 3 is an illustrative view showing a state in which the characteristic adjustment electrode and the ground electrode are connected after the embodiment shown in FIG. 1 is superimposed. In the figure, 10 is a triplate type stripline filter, 12, 14 and 24 are dielectric substrates, 16 is a ground electrode, 113 is a resonant electrode, 20 is a spacing, 26 is a characteristic adjustment electrode, and 28 is a resonance frequency adjustment electrode. , and 30
indicates a coupling coefficient adjustment electrode. Patent Applicant Murata Manufacturing Co., Ltd. Agent Patent Attorney Yama 1) Yoshihito'-* 21

Claims (1)

[Scope of Claims] First and second dielectric substrates each having a resonant electrode formed on one main surface thereof are disposed such that their respective resonant electrodes face each other, and In a triplate type strip line filter stacked with a third dielectric substrate sandwiched between the body substrates, a position related to the resonant electrode is provided on one or both principal surfaces of the third dielectric substrate. A triplate type stripline filter characterized in that a characteristic adjustment electrode is formed which is connected to ground as necessary.