JPH0644202U - Bandpass filter structure - Google Patents

Abstract

(57) [Summary] (Correction) [Purpose] Even if the number of resonators is increased and configured as a multistage resonator, the mounting area of the element is limited and the bandpass can be made smaller. The purpose is to provide the structure of the filter. [Structure] A strip line type band pass filter having a conductor pattern formed on one main surface of a dielectric substrate is divided into several pieces of filter pieces 4, 5 and 6, and these pieces are superposed and three-dimensionally assembled to form a filter piece. The ground plate and the conductor patterns are electrically connected to each other at the ends of 4, 5, and 6.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a bandpass filter of a microwave transmission device, and more particularly to downsizing of a filter shape accompanying miniaturization of a portable device or the like.

[0002]

[Prior art]

 With the recent miniaturization of electronic devices and the like, the demand for miniaturization has increased in the field of microwave transmission equipment as well, and the conventional waveguide resonance is used as a bandpass filter on a dielectric substrate. The use of stripline resonators with conductor patterns formed on the inside is becoming the mainstream.

For example, as shown in FIG. 4 (a), a ground plate 2 is attached to one main surface of a dielectric substrate 1 and a conductive pattern 3 is attached to the other main surface of the substrate 1 to open both ends. Stripline bandpass filters are widely used in which half-wave resonators are connected in parallel. Further, as shown in FIG. 3B, the above-mentioned conductive pattern 3 is arranged so as to be sandwiched between the dielectric substrate 1 and the dielectric substrate 1 ′ having a ground plate 2 ′ attached to one main surface. Stripline bandpass filters are also often used.

However, in the stripline bandpass filter having the above-mentioned configuration, if the number of the resonators is increased to form a multistage structure, the external shape of the filter element becomes long, and therefore, when the filter element is incorporated in the device. In addition, the area occupied by the element increases, and there is a drawback that the device cannot be downsized.

[0005]

[The purpose of the device]

 The present invention was made in order to eliminate the drawbacks of the conventional stripline bandpass filter as described above, and even when the number of resonators is increased and the multistage structure is adopted, the element It is an object of the present invention to provide a bandpass filter structure that can be mounted in a miniaturized device by limiting the mounting area.

[0006]

[Outline of the device]

 A stripline type bandpass filter with a conductor pattern formed on one main surface of a dielectric substrate was divided into several pieces, and these were superposed and three-dimensionally assembled, and the patterns were electrically connected to each other. It is a thing.

[0007]

【Example】

 Hereinafter, the present invention will be described in detail with reference to the drawings illustrating an embodiment. 1 (a) and 1 (b) are respectively an external perspective view and an AA cross-sectional view showing the configuration of an embodiment of a stripline bandpass filter according to the present invention, in which 4 through 6 are conventional ones. It is a filter piece obtained by dividing a stripline bandpass filter into a predetermined length, and is arranged so as to be substantially parallel to each other. Thus, the ground plate and the conductive patterns are connected to each other at the end of each filter piece, and the whole is molded with the molding material 7. With this configuration, the size in the height direction increases, but the mounting area for mounting it on a printed circuit board in the device is as small as about 1/3 in this example, and the size of the printed circuit board is reduced. It is possible to reduce the area and further downsize the device.

FIG. 2 (a) is a perspective view showing a second embodiment of the bandpass filter according to the present invention, and 8 is necessary for the filter construction on the flexible substrate as shown in FIG. 2 (b). A conductive pattern sheet having necessary conductive patterns arranged thereon, and as shown in the exploded front view of FIG. 7C, the conductive pattern sheet 8 is a dielectric substrate 9 and 10 having a ground plate attached to the other main surface thereof. 11 and 12, and 13 and 14 are configured to hold each other. As a result, only the conductor pattern can be separately mass-produced, and the cost can be reduced including the reduction of the number of assembly steps.

Further, as shown in FIG. 3A, in the configuration in which the upper and lower ground plates are made common by eliminating the gap between the filter pieces, the ground plate formed on the flexible substrate is the same as the conductive pattern sheet 8. The pattern sheet 15 may be configured by alternately folding the dielectric substrate while sandwiching the dielectric substrate as shown in FIG. 9B showing a cross-sectional view taken along the line BB in the figure, which enables further cost reduction. Becomes The present invention has been described above by taking the stripline type bandpass filter divided into three as an example. However, the present invention is not limited to this and is applied to a stripline type bandpass filter having a configuration as shown in FIG. However, it may be divided into a large number.

[0010]

[Effect of device]

 Since the present invention is configured as described above, even if the number of stages of the stripline type bandpass filter is increased, the mounting area on the printed circuit board when incorporating it in a device or the like is not increased, but rather this is increased. This has a remarkable effect in reducing the size of the reduction device and reducing the cost of the filter element.

[0011]

[Brief description of drawings]

1A and 1B are an external perspective view and an AA cross-sectional view showing a configuration of an embodiment of a stripline bandpass filter according to the present invention, respectively.

FIG. 2A is a perspective view showing a second embodiment of the bandpass filter according to the present invention. (B) is a figure which shows the structure of the electrically conductive pattern sheet used for this. (C) is an exploded front view of (a).

FIG. 3A is a sectional view showing a third embodiment of the bandpass filter according to the present invention. (B) is BB in (a) figure
Sectional view.

4A and 4B are external perspective views showing the configuration of a conventional stripline bandpass filter, respectively.

[Explanation of symbols]

 1, 1 ', 9 to 14 ... Dielectric substrate 2, 2' ... Ground plate 3 ... Strip line 4, 5, 6 ... Filter piece 7 ... Mold material 8 ... Conductivity Pattern sheet 15: Earth pattern sheet

Claims (1)

[Scope of utility model registration request] 1. A stripline bandpass filter having a conductor pattern formed on one main surface of a dielectric substrate is divided into several pieces, and these pieces are superposed and three-dimensionally assembled to electrically connect the patterns to each other. The structure of the bandpass filter, which is characterized in that