JPH0633683Y2 - Three-conductor filter package - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a three-conductor structure filter package used for a small electronic circuit or the like.

<Prior Art> A filter package in which a three-conductor structure filter having a strip line pattern formed by arranging a plurality of resonance lines in parallel on the contact surface of two laminated dielectric substrates is housed in a case is small. Since it has a simple structure, it is suitable for use in small electronic circuits.

In this three-conductor structure filter, the frequency response depends on the size of the resonance line, the structure of the outer conductor to which the resonance line is connected,
It depends on the shape and dielectric constant of the substrate. Therefore, if there are variations in the dielectric constant, size, etc. of the substrate, the frequency response characteristics of the filter will substantially change and deviate from the predetermined frequency range.

Therefore, in order to keep the frequency response characteristic of the filter within a predetermined frequency range, adjusting devices such as adjusting screws and external capacitors have been used. Alternatively, a caulking structure (clamping device) has been applied in which the dielectric material is compressed to change the electrical parameter of the line.

However, each of the above means causes an increase in the size of the filter and a price increase, and cannot be said to be a good adjusting means.

<Problems to be Solved by the Invention> On the other hand, as a simple means for correcting the drawbacks of the above means, by removing a portion of the outer conductor formed on the upper surface of the upper dielectric substrate located on the resonance line, the opening is performed. It reduces the distributed capacitance between the end and the outer conductor, increases the response frequency of the filter,
A device capable of frequency adjustment was proposed in Japanese Patent Publication No. 61-19122.

However, in this adjusting means, the case housing the filter is in close contact with the upper and lower outer surfaces of the filter in order to reduce the thickness of the case. For this reason,
The dielectric may come into direct contact with the case through the outer conductor removal portion formed on the upper surface of the upper dielectric substrate, and the distributed capacitance may change after the adjustment, causing the frequency to shift again.

An object of the present invention is to provide a three-conductor structure filter package having a structure in which the frequency does not change even when the filter is housed in a case.

<Means for Solving the Problems> The present invention relates to an outer conductor formed on an upper surface of an upper dielectric substrate.
An opening for adjusting the response frequency is formed in a portion located on the resonance line, and the opening is formed on a surface of the case accommodating the filter in a close contact in the thickness direction, the surface corresponding to the opening. It is characterized in that a surrounding recess is formed.

<Operation> By removing a part of the outer conductor formed on the upper surface of the upper dielectric substrate on the resonance line by forming the adjustment opening, the response frequency is increased and the frequency can be adjusted.

Therefore, when the center frequency is shifted to the low frequency side,
When the opening is formed and corrected to the lower side, and when the opening is shifted to the high frequency side, a conductor is added to the opening to correct to the higher side.

By the way, the upper surface of the filter in which the adjustment opening is formed comes into contact with the inner surface of the upper portion of the filter by housing the filter in a case. However, since the case is preliminarily formed with the recess surrounding the opening, the dielectric substrate exposed from the opening is not in contact with the case, and the distribution between the open end and the outer conductor is small. No change in capacity. Therefore, the adjusted response frequency does not change again.

<Embodiment> An embodiment of the present invention will be described with reference to the accompanying drawings.

As shown in Figs. 1 and 2, two dielectric substrates 1 and 2 are stacked.
On the lower dielectric substrate 1, there is formed a strip line pattern 5 in which the resonance lines 3a and 3b and the resonance line 3c are arranged side by side in an interdigitated manner. Further, an outer conductor 6 is formed on the lower dielectric substrate 1 around the strip line pattern 5 and on the entire side of the strip line pattern 5 as well as on the lower surface thereof. Track pattern 5
Is connected to the short-circuit side edges 6a, 6b of the outer conductor 6 formed around the periphery of the outer conductor 6 and its open ends 4a, 4b, 4c and the short-circuit side edges 6a, 6b.
An insulating space is formed between them. In addition, the resonant lines 3a, 3b, 3c
Has its length set to 1/4 wavelength or 1/2 wavelength. still,
The resonance lines 3a and 3b and the resonance line 3c may be extended from the same side edge of the outer conductor and arranged in a comb shape.

The resonance lines 3a and 3b have outer edges extending to the cutouts of the outer conductor 6 to form external lead electrodes 7a and 7b.

Upper dielectric substrate 2 disposed on the lower dielectric substrate 1
An outer conductor 8 electrically connected to the outer conductor 6 is formed on the upper surface and the peripheral surface thereof. Further, the upper dielectric substrate 2 has a rectangular shape on the side portion corresponding to the external extraction electrodes 7a, 7b, which enables connection between the external extraction electrodes 7a, 7b and an input / output line of a circuit board (not shown). Connection grooves 10a and 10b are formed as required.

A transmission line pattern having a mirror image relationship with the strip line pattern 5 is also formed on the lower surface of the upper dielectric substrate 2 so that they are in surface contact with each other in the superposed state. The strip line pattern 5 may be formed between the upper dielectric substrates 2 without a gap.

In order to adjust the response frequency, a portion of the outer conductor 8 formed on the upper surface of the upper dielectric substrate 2 located on the open ends 4a, 4b, 4c of the resonance lines 3a, 3b, 3c is adjusted. Opening 11
a, 11b, 11c are formed. The adjustment openings 11a, 11b, 11c
Is formed by removing the outer conductor 8 by laser processing, sandblasting, or the like, in addition to cutting with a tool. It should be noted that a predetermined adjustment effect can be achieved even if the adjustment openings are formed at positions on the resonance lines 3a, 3b, 3c other than the open ends 4a, 4b, 4c.

In the above structure, the filter F has the adjustment openings 11a, 11b, 11
By forming c, the center of the response frequency is adjusted to the higher side. Therefore, when the center frequency is deviated to the low frequency side, the openings 11a, 11b, 11c are formed and corrected, and when deviated to the high frequency side, the openings 11a, 11b,
Add a conductor to 11c and correct it to the lower side. Alternatively, a peelable conductive piece may be joined in advance to the openings 11a, 11b, 11c, and the conductor may be peeled off for adjustment.

The filter F having the above structure is housed in the case 20 as shown in FIGS. The case 20 has an internal height equal to the thickness of the filter F to prevent the thickness from increasing.

In the above structure, in order to stably hold the filter F in the case 20, the adjustment openings 11a, 11b, 11c of the filter F are formed on the inner side surface of the case 20 by the following means. Touch the surface.

That is, as shown in FIGS. 3 and 4, the upper wall 20a of the case 20 is
Of the adjustment opening 11a, 11b, 11c corresponding to the depression 21
a, 21b, 21c are formed, and the adjustment openings 11a, 11b, 11c are depressed portions.
It is surrounded by 21a, 21b, 21c in a non-contact manner.

Thus, even if the filter F whose frequency has been adjusted by the adjustment openings 11a, 11b, 11c is mounted in the case 20, the frequency does not change again and no readjustment is necessary.

When forming the depressions 21a, 21b, and 21c, even if the upper surface of the case 20 slightly bulges, it is possible to prevent the thickness of the case 20 from increasing by reducing the bulging amount as much as possible.

<Effects of the Invention> As described above, the present invention provides the outer conductor 8 of the upper dielectric substrate 2.
Since the depressions 21a, 21b, 21c are formed on the inner surface of the case 20 corresponding to the adjustment openings 11a, 11b, 11c formed on the upper surface of the adjustment openings 11a, 11b, 11c, the adjustment openings 11a, 11b, 11c are surrounded. , The case 20 is connected to the upper dielectric substrate 2 through the openings 11a, 11b, 11c.
Since the filter F is housed in the case 20, the distributed capacitance does not change and the frequency characteristic does not change. Therefore, there is an excellent effect that the frequency can be made appropriate.

[Brief description of drawings]

The attached drawings show an embodiment of the present invention, and FIG. 1 shows a filter F.
2 is a perspective view of the same and FIG. 3 is a filter F.
FIG. 4 is a partially cutaway plan view showing a state in which the is housed in the case 20, and FIG. 4 is a sectional view taken along the line AA in FIG. 1; Lower dielectric substrate, 2; Upper dielectric substrate, 3a, 3b, 3c; Resonant line, 5; Strip line pattern, 6, 8; Outer conductor, 11a, 11
b, 11c; adjusting opening, 20; case, 21a, 21b, 21c; recess,
F; filter

Claims (1)

[Scope of utility model registration request] 1. A contact surface between two dielectric substrates to be laminated,
In a case where a three-conductor structure filter in which a strip line pattern formed by arranging a plurality of resonance lines in parallel is arranged in a case, the outer conductor formed on the upper surface of the upper dielectric substrate is positioned on the resonance line. An opening for adjusting the response frequency is formed in the portion to be formed, and a recess for surrounding the opening is formed on the surface corresponding to the opening of the case that tightly accommodates the filter in the thickness direction. A three-conductor structure filter package characterized by being formed.