JPH1168402A - Strip line half wavelength side combining filter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify the structure of a pattern and to reduce an insertion loss by making the part of a specific wavelength, which is not overlapped with an adjacent line pattern of a line pattern positioned at both edges in a direction vertical to the longitudinal direction of the line pattern, an input/output line. SOLUTION: Three line patterns 11 to 13 of a length λ/2 are formed on a dielectric substrate 10 and two side combining parts consisting of the mutually opposed parts of a length λ/4 of the adjacent line patterns 11 to 13 to constitute a filter of two filter stages. At the line patterns 11 and 13 on an outermost side, an input/output line is respectively formed at the part of a length λ/4 of a left half part and a right half part. Then, an n-stage filter is constituted by (n+1)-number of line patterns in general. Parameters W3 and S3 are fixed so as to obtain desired attenuation characteristic by simulation with the line width W3 and the interval S3 of each line pattern 11 to 13 as parameters.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a stripline half-wavelength side coupling filter and a design method thereof.

[0002]

2. Description of the Related Art A conventional bandpass type stripline half-wavelength side coupling filter has an n +
It consists of a set of side couplings and input / output lines. FIG. 3 is a perspective view showing a configuration example of a three-stage stripline half-wavelength side coupling filter, and FIG. 4 is a top view seen from above. On the dielectric substrate 30, three patterns 32, 33, and 34 having a length of λ / 2 (λ: wavelength) and two line patterns 31 and 35 having a length of λ / 4 are formed.
Input / output lines 36 and 37 are formed at the ends of the first and the 35th. This stripline half wavelength side coupling filter
The line width of each line pattern and the interval between them are appropriately determined, and the design is performed so that required characteristics can be obtained. The width of the input / output line is determined so that its characteristic impedance is 50Ω, and its length is determined to be about the external terminals required for mounting.

[0003]

In the prior art, n + 1 sets of side coupling sections are provided to constitute an n-stage bandpass type stripline half-wavelength side coupling filter. Was formed on the dielectric substrate. However, in such a conventional technique, it is not considered to configure the stripline half-wavelength side coupling filter having the same number of stages with a smaller number of line patterns and to further improve the characteristics thereof.

It is an object of the present invention to provide a strip line half-wavelength side coupling filter having a smaller insertion loss and a reduced number of line patterns.

[0005]

In order to achieve the above-mentioned object, the present invention relates to a method for producing a semiconductor device, comprising the steps of: A strip line formed by arranging n line patterns on a dielectric substrate in parallel at predetermined intervals and overlapping by １ ／ wavelength in the length direction of the line patterns. A half-wavelength side coupling filter is provided.

The present invention also relates to a quarter wavelength portion of two line patterns located at both ends in a direction perpendicular to the length direction of the line pattern, which does not overlap with an adjacent line pattern. 2. The strip line half-wavelength side coupling filter according to claim 1, wherein

[0007]

Embodiments of the present invention will be described below. 1 and 2 show a configuration example of a stripline half-wavelength side coupling filter according to the present invention.
FIG. 2 is a perspective view, and FIG. 2 is a top view. The number of filter stages is two. Three line patterns 11, 12, and 13 having a length of λ / 2 are formed on the dielectric substrate 10, and have a structure having two side coupling portions. That is, λ of the line pattern 11
The right half of the / 4 length and the left half of the λ / 4 length of the line pattern 12 form the first side connection portion, and the right half of the λ / 4 length of the line pattern 12 and the left half of the λ / 4 length of the line pattern 13 Form a second side joint. Further line pattern 1
1 and λ / 4 of line pattern 13
The right half of the length forms an input / output line.

Although the stripline half-wavelength side coupling filter of the present invention described above is an example of a two-stage bandpass filter, in general, in order to have n stages, n + 1 line patterns having a length of λ / 2 are formed by a dielectric material. Construct on a substrate. In this design, the stripline half-wavelength side coupling filter of the present invention has characteristics similar to those of the (n-1) -stage type filter and the conventional n-stage type of filter described with reference to FIGS. To This procedure is the following (1) to (4). (1) A conventional n-stage stripline half-wavelength-side coupling filter is designed to obtain desired filter characteristics. This design method is performed by a conventionally known method. (2) A conventional n-1 stage stripline half-wavelength side coupling filter is designed so as to obtain desired filter characteristics. (3) The length of the two outer line patterns of the stripline half-wavelength side coupling filter designed in (2) above is λ
Line pattern extending from / 4 to λ / 2 (same width)
And (4) Characteristic simulation is performed on the shape obtained in (3) using the pattern width W3 and the pattern interval S3 shown in FIG. 2 as variable parameters, and the stripline half-wavelength side coupling designed in (1) is performed. The parameters W3 and S3 are determined so that an attenuation characteristic that matches the attenuation characteristic determined by the simulation of the filter characteristic is obtained.

FIG. 5 shows an example of an attenuation characteristic obtained by simulation of a stripline half-wavelength side coupling filter designed by the method described above in comparison with an example of a conventional stripline half-wavelength side coupling filter. 4 is a comparison of the damping characteristics of FIG. 1 and FIG. That is, the center frequency is 1G
In Hz, the conventional type is a three-stage type as shown in FIGS. 3 and 4, and the present invention is a two-stage type as shown in FIGS. The dielectric substrate is a ceramic substrate having a relative dielectric constant of 67 (having a thickness of 1.86 m).
m), and the λ / 4 length on this substrate is about 9.15 mm
Becomes The dimensions of each filter were as follows. Dimensions of conventional type (FIG. 4): W1 = 0.13 mm S1 = 0.075 mm S2 = 0.89 mm Dimensions of the present invention (FIG. 2): W3 = 1.88 mm S3 = 0.34 mm Note that phase characteristics and a wider range Although the attenuation characteristics in the frequency range are omitted in FIG. 5, they substantially match.

As can be seen from the results shown in FIG. 5, the stripline half-wavelength side coupling filter of the present invention has the same attenuation characteristics as the conventional type, and can realize characteristics with small insertion loss. Further, as is apparent from a comparison between FIG. 1 and FIG. 3, the present invention has the advantage that the structure of the filter is simplified and the process for pattern formation can be simplified.

[0011]

According to the present invention, there is an effect that a bandpass type strip line half-wavelength side coupling filter which has a simple pattern structure, is easy to manufacture, and has a small insertion loss can be realized.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a configuration example of a stripline half-wavelength side coupling filter according to the present invention.

FIG. 2 is a top view of the filter of FIG.

FIG. 3 is a perspective view showing a configuration example of a conventional stripline half-wavelength side coupling filter.

FIG. 4 is a top view of the filter of FIG. 3;

FIG. 5 is a comparison diagram of the attenuation characteristics of the filters of FIGS. 1 and 3;

[Explanation of symbols]

 10 Dielectric substrate 11-13 Line pattern

Claims (2)

[Claims] When n is a positive integer of 3 or more, n line patterns having the same line width and a length of １ ／ wavelength are arranged in parallel at a predetermined interval. A strip line half-wavelength side coupling filter, which is formed on a dielectric substrate so as to overlap by １ ／ wavelength in the length direction of the line pattern. 2. The two line patterns located at both ends in a direction perpendicular to the length direction of the line pattern,
2. The input / output line according to claim 1, wherein a quarter wavelength portion having no overlap with an adjacent line pattern is used as an input / output line.
The stripline half-wavelength side coupling filter as described.