JP2557081Y2 - Micro stripline filter - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a microstrip line filter used for microwave communication such as a car phone, a mobile phone, or a satellite communication, and more particularly to a surface mount on a conductive pattern on a circuit board. Type.

[0002]

2. Description of the Related Art A conventional microstrip line filter will be described with reference to FIGS. FIG. 9 is a schematic diagram showing the front side of a micro strip line filter in a conventional example. FIG. 10 is a schematic diagram showing the back side of a micro strip line filter in a conventional example. 9 and 10, a dielectric substrate 21 is formed of a substrate made of ceramic or the like having a high dielectric constant, and strip lines 22, 23, 2
4 are formed. In the strip lines 22 and 23, the input conductive portion 25 and the output conductive portion 26 of the micro strip line filter are formed as continuous conductive patterns, respectively. Further, each of the strip lines 22 to 24 is connected to a ground electrode 30 formed on the other surface of the dielectric substrate 21 via connecting portions 27 to 29. The conductive film forming the conductive patterns is baked after, for example, applying a silver paste on the dielectric substrate 21. The strip lines 22 to 24 formed on one surface of the dielectric substrate 21 and the ground electrode 30 formed on the other surface of the dielectric substrate 21 constitute a micro strip line filter. Adjustment of the frequency characteristic of the micro strip line filter or impedance matching with an external circuit is performed by cutting off a part of the input / output conductive portions 25 and 26.

The micro strip line filter as described above is mounted on a circuit board (not shown),
Both ground electrodes are electrically connected via solder. The input / output conductive portions 25 and 26 of the micro strip line filter are soldered to desired conductive patterns on a circuit board (not shown), for example, using lead wires. The microwave signal input to the input conductive portion 25 of such a micro strip line filter has an inductance by each of the strip lines 22 to 24, and each of the strip lines 22 to 24 and the ground electrode 30, or each of the strip lines 22 to 24. Constitutes a filter. When a microwave signal is input to the input conductive unit 25 in the micro strip line filter having such a configuration, a microwave signal having a desired frequency is selected and output from the output conductive unit 26.

[0004]

In recent years, there has been a strong demand for miniaturization of electronic devices, and there has been a tendency for the spacing between conductive patterns on a circuit board incorporated in the electronic device to be narrow. For this reason, miniaturization of the external dimensions of the micro stripline filter is demanded. However, in the micro strip line filter in the above-mentioned conventional example, the input / output conductive portions 25 and 26 are formed even if the interval between the strip lines 22 to 24 is narrowed in accordance with the interval between the conductive patterns on the circuit board (not shown). Therefore, there is a problem that the outer shape of this portion becomes large. In addition, lead wires for electrically connecting the input / output conductive portions 25 and 26 and the conductive patterns of the circuit board (not shown) and the work of attaching the lead wires are required.

An object of the present invention is to solve the above-mentioned problems, and an object of the present invention is to provide a microstrip line filter having a small external dimension and easy to mount on a circuit board.

[0006]

In order to achieve the above object, a micro strip line filter according to the present invention comprises:
A conductive pattern formed of at least two strip lines formed on one surface of at least one dielectric substrate, and a ground electrically connected to the conductive patterns formed on the other surface of the dielectric substrate An electrode, insulated from the ground electrode, formed opposite to each of the conductive patterns, respectively, capacitively coupled to each of the conductive patterns, and opposing protruding portions so as to face each other in two directions. And an input / output conductive portion in which is formed.

[0007]

According to the work for the present invention, input and output conductive portions, together are formed to face each other with the conductive pattern in a region where the ground electrode is formed, it and the conductive pattern
Opposing each other in two directions that are capacitively coupled
The opposite protruding portion is formed in such a manner. Therefore, since the strip line and the input / output conductive portion are capacitively coupled, there is no need to form an input / output conductive portion protruding from the strip line on the dielectric substrate. Further, impedance matching adjustment, or to an external circuit of the frequency characteristic of the micro-strip line filter is a part of the input conductive portions formed on the ground electrode side
This is done by shaving the opposing projections . Therefore,
The micro stripline filter is miniaturized.
In addition, since the micro strip line filter has an input / output conductive part on the ground electrode side, it can be mounted on the conductive pattern formed on the circuit board together with the solder, and can be connected to other electronic components. It is attached in the same way. Therefore, the lead wire connecting the conductive pattern and the input / output conductive portion and the work of attaching the lead wire are not required. Furthermore, since the input projecting portion and the output conducting portion which are capacitively coupled to the conductive pattern are provided so as to oppose each other in two directions, the attenuation is improved in the frequency characteristics, and the micro-channel is formed in this portion. frequency characteristics of the stripline filter is adjusted correctly, or can be easily performing impedance matching with an external circuit.

[0008]

[Embodiment] One embodiment of the present invention will be described with reference to FIGS.
A reference example will be described. FIG. 1 is a schematic view showing a front side of a micro strip line filter according to a reference example of the present invention. FIG. 2 shows a micro-computer according to a reference example of the present invention.
It is the schematic which showed the back side of the stripline filter. FIG. 3 is a sectional view taken along line AA ′ in FIG. 1 to 3, a dielectric substrate 1 is made of a substrate having a high dielectric constant such as ceramics, and strip lines 2 to 4 are formed on one surface thereof. The strip lines 2 and 3 are connected to the side surfaces of the dielectric substrate 1 via connection portions 7 and 7 ′ which are electrically connected to each other independently, and the strip line 4 is connected via a connection portion 7 ″. Are connected to the ground electrode 8 formed on the other surface of the dielectric substrate 1. On the other surface of the dielectric substrate 1, input / output conductive portions 5 and 6 are insulated from the ground electrode 8, and , And are formed so as to face the strip lines 2 and 3. The input / output conductive portion 5
And 6 are arranged on the other surface of the dielectric substrate 1 at positions facing each other. The conductive films forming the strip lines 2 to 4, the input / output conductive portions 5, 6 and the ground electrode 8 formed in this way are
For example, it is formed by applying a silver paste thereon and then baking. Adjustment of the frequency characteristics of the micro strip line filter or impedance matching with an external circuit can be easily performed by removing a part of the input / output conductive portions 5 and 6 formed on the ground electrode 8 side.

[0009] The micro strip line filter as described above is mounted on a circuit board 11 as shown in FIG. 3, and both ground electrodes are electrically connected via solder 13. At the same time, the input / output conductive portions 5 and 6 of the micro strip line filter are connected to the land electrodes 12 connected to the desired conductive patterns on the circuit board 11 by solders 13, respectively. The microwave signal input to the input conductive part 5 of such a micro strip line filter is formed by the inductance of each strip line 2 to 4, the strip line 2 to 4 and the ground electrode 8, the strip line 2 and the strip line 3, Since the filter is constituted by the capacitance of the strip line 3 and the strip line 4, a desired microwave signal is selected and output from the output conductive unit 6.

Next, an embodiment of the present invention will be described with reference to FIGS. 4 and 5. FIG. FIG. 4 is a schematic diagram showing the front side of the micro strip line filter in the embodiment of the present invention. FIG. 5 is a schematic view showing the back side of the micro strip line filter in the embodiment of the present invention.
The dielectric substrate 1 is a substrate made of ceramic or the like having a high dielectric constant, and has strip lines 2 to 4 formed on one surface thereof. The strip lines 2 to 4 are
The side surfaces of the dielectric substrate 1 are connected to ground electrodes 8 formed on the other surface of the dielectric substrate 1 via connection portions 7 to 7 ″ that are electrically connected to each other independently. On the other surface of the dielectric substrate 1, there are formed input / output conductive portions 5 'and 6' insulated from the ground electrode 8 and opposed to the strip lines 2 and 3. 5 'and 6' are formed with opposing projections 9, 10 which are opposed to each other in two directions, for example, in the left-right direction and the front-rear direction, as shown in the figure.
A pole having an excellent frequency can be obtained, and a part of the pole can be cut to easily adjust the frequency characteristic of the microstrip line filter or easily perform impedance matching with an external circuit.

Another embodiment of the present invention will be described with reference to FIGS. FIG. 6 is a schematic diagram showing a front side of a micro strip line filter according to another reference example of the present invention. FIG. 7 is a schematic view showing a back side of a micro strip line filter according to another reference example of the present invention. FIG. 8 is a sectional view taken along the line BB 'of the microstrip line filter shown in FIG. For example, strip lines 2 to 4 as shown in FIG. 4 are formed on one surface of the dielectric substrate 1, and a ground electrode 8 'is formed on the entire surface of the other surface of the dielectric substrate 1. On the other surface of the dielectric substrate 1 ', a ground electrode 8 and input / output conductive portions 5, 6 or input / output conductive portions 5', 6 'as shown in FIG. 2 or 5 are formed. Such dielectric substrates 1 and 1 'are overlapped so that the ground electrode 8 and the ground electrode 8' of each other are located outside. Thus, the strip lines 2 to 4, the ground electrode 8,
The microstrip line filter on which the 8 'and the input / output conductive portions 5, 6 or the input / output conductive portions 5', 6 'are formed is attached to the circuit board 11 as shown in FIG. With such a microstrip line filter, the number of elements constituting the filter can be increased, and the frequency characteristics can be made into a desired shape.

Although the embodiments of the present invention have been described in detail, the present invention is not limited to the above embodiments. And
Various design changes can be made without departing from the present invention described in the utility model registration claims. For example, the number of strip lines and how to ground them include those of the comb line type and the interdigital type. In addition, it is possible to arbitrarily increase the number of superposed dielectric substrates or change the shape of the input / output conductive portion, particularly the shape of the opposing projecting portion. Further, for the formation of the conductive pattern, the ground electrode, or the input / output lands formed on the dielectric substrate, other manufacturing methods such as photo-etching can be adopted.

[0013]

According to the present invention, the other side of the dielectric substrate is opposed to the strip line in two directions capacitively coupled.
In this case, since the input / output conductive portions having the opposed protruding portions formed so as to face each other are provided, it is possible to reduce the size of the microstrip line filter and to eliminate the lead wires and the work of attaching them. In addition, the input / output conductive part can be polarized, which not only improves the attenuation characteristics, but also enables accurate adjustment of the frequency characteristics of the microstrip line filter and impedance matching with external circuits. Can be easily done.

[Brief description of the drawings]

FIG. 1 is a schematic view showing a front side of a micro strip line filter according to a reference example of the present invention.

FIG. 2 is a schematic diagram showing a back side of the micro strip line filter according to a reference example of the present invention;

FIG. 3 is a sectional view taken along line AA 'in FIG.

FIG. 4 is a schematic view showing a front side of the micro strip line filter in the embodiment of the present invention.

FIG. 5 is a schematic view showing a back side of the micro strip line filter in the embodiment of the present invention.

FIG. 6 is a schematic diagram showing a front side of a micro strip line filter according to another reference example of the present invention.

FIG. 7 is a schematic view showing a back side of a micro strip line filter according to another reference example of the present invention.

FIG. 8 is a sectional view taken along the line BB 'of the microstrip line filter shown in FIG.

FIG. 9 is a schematic diagram showing a front side of a micro strip line filter in a conventional example.

FIG. 10 is a schematic view showing the back side of a micro strip line filter in a conventional example.

Claims (1)

(57) [Scope of request for utility model registration] 1. A conductive pattern comprising at least two strip lines (2, 3) formed facing one surface of at least one dielectric substrate (1, 1 '), and a conductive pattern formed on the other surface of the dielectric substrate (1). Earth electrodes 8, 8 'electrically connected to the respective conductive patterns, and insulated from the ground electrodes 8 or 8', formed opposite to the respective conductive patterns 2, 3; And input / output conductive portions 5 'and 6', each of which is capacitively coupled to the conductive pattern and has opposed protruding portions 9 and 10 formed so as to face each other in two directions. A micro strip line filter.