JPH0374523B2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a high frequency filter device for handling high frequency signals such as UHF, and more specifically, a high frequency filter device comprising a cavity and an internal conductor element provided in each cavity on a substrate. The present invention relates to a method of assembling a high-frequency filter device made of the following methods.

In the conventional method of assembling a high frequency filter device, a cavity is attached to a substrate, an inductor is installed in the narrow internal space of the cavity, and coupling elements are installed on both sides of the inductor in the internal space. This method requires very detailed work, so
This work is difficult to perform, and the products produced by such work have the disadvantage that the high frequency characteristics deviate from the predetermined ones.

SUMMARY OF THE INVENTION The present invention aims to eliminate the above-mentioned drawbacks and provide a method for assembling a high-frequency filter device that is easy to assemble and has good high-frequency characteristics.

The drawings showing the embodiments of the present application will be described below. 1 to 8, a high frequency filter device A consists of a substrate 1 and a high frequency filter (bandpass filter) B attached to the substrate. The substrate 1 is formed by pasting conductor foils (copper foils) 3 and 4 on the front and back surfaces of an insulating plate 2, respectively. These conductor foils 3 and 4 form a ground conductor. Note that this substrate 1 may be formed of a metal plate with good conductivity, such as a copper plate or an iron plate. In the substrate 1, 5 is a capacitor fixing part, and 6 is an inductor fixing part, each of which has a through hole. Reference numeral 7 indicates a cavity fixing portion, which is constructed with a plurality of square holes 8. Next, in the high frequency filter B, 10,
Reference numerals 10 indicate cavities, and in this embodiment, side plates 11 each made of a metal plate with good conductivity, such as a copper plate or an iron plate plated with copper.
By combining the three pieces and the two end plates 12 as shown in the figure and joining them by soldering to each other,
Two cavities 10, 10 are integrally formed. (The middle side plate 11 has both cavities 10, 1
It is also used as 0. ) Said side plate 11 and end plate 1
2, 13 is a fitting portion, and 14 is a fitting piece, which are provided to ensure that the mutual positional relationship is as specified when the side plate 11 and end plate 12 are combined. Reference numeral 15 denotes a support plate attachment part, which is formed by bending and raising a part of the side plate 11, and has a screw hole 16 bored therein. Reference numeral 17 denotes a recessed portion, and the height of the lower edge 17a thereof is formed lower than the height of the mounting portion 15 so that a supporting plate, which will be described later, does not come into contact with it. 18 is a lid fixing piece, which is attached to the base 1.
8a is formed thin as shown in the figure. 19 indicates a fastening piece. Next, the members provided inside the cavity 10 will be explained. Reference numeral 21 denotes a variable capacitor, which has a ground terminal 22 and an inductor connection terminal 23, and the ground terminal 22 is fixed to the board 1 by a fixing threaded rod 24. The threaded rod 24 with a stopper is made of a conductive material (metal).
This threaded rod 24 allows the ground terminal 22 and the conductor foil 4 on the back surface of the substrate 1 to be electrically connected to each other. 25 is an inductor, which includes the main body 25a and the support part 2.
5b. The support portion 25b has the role of mechanically fixing the main body 25a to the substrate 1 and the role of electrically connecting one end of the main body 25a to the ground conductor (conductor foil 4) of the substrate 1. The support portion 25b has a positioning piece 26, and when the lower end of the support portion 25b is attached to the substrate 1, the inductor 2
5 is positioned at a predetermined height from the substrate 1. Next, reference numeral 28 denotes a support plate, which is formed by pasting a conductor foil (copper foil) on one surface of an insulating plate 29 (referred to as a printed circuit board). In this support plate 28, 30, 30 are internal parts of the cavity, just like the cavity 10,
It is formed to have dimensions corresponding to the inner dimensions of the cavity 10 so as to fit within the cavity 10. 31 is a notch, 3
2 and 32 are terminal portions, and 33 is a through hole through which a set screw rod is inserted. Reference numeral 34 denotes an adjustment hole, which is formed at a position that overlaps the rotation axis of the variable capacitor 21 in projection.
Next, in various conductors formed by printing wiring means (etching means) on conductor foil, 35, 35 are ground parts, 36, 36 are terminals, one as an input terminal and the other as an output terminal. Each is used. 37 is a connecting conductor. 38, 39
each represents a coupling element, and one end of each is connected to the ground part 3.
5, and the other end is connected to a terminal 36 or a connecting conductor 37. Next, 40 is a trimmer capacitor for adjustment, which is connected between the connecting conductor 37 and the ground portion 35. 41 is the lid,
It is formed by pressing a material with good conductivity (for example, a copper plate), and has through holes 42 and 43 for inserting adjustment rods at locations that projectively overlap with the axis of the variable capacitor 21 and the axis of the trimmer capacitor 40, respectively. has,
It also has a through hole 44 for fastening. Furthermore, this lid 41
is adapted to shield the space inside the cavity 10.

Next, the procedure for assembling the above structure will be explained.
First, as shown in FIG. 4, the variable capacitor 21 is fixed to the variable condenser fixing portion 5 of the substrate 1 with a fixing threaded rod.
Next, the support portion 25b of the inductor 25 is inserted through the fastening portion 6 and soldered to the ground conductor 4, and one end of the inductor body 25a is soldered to the connection terminal 23. Note that the support portion 25b may be soldered to the ground conductor 3 on the surface of the board, or may be soldered to both 3 and 4.

Next, the cavities 10, which have been assembled in advance as shown in FIG. 4, are assembled. This assembly is carried out by inserting each fastening piece 19 into each square hole 8 and soldering its tip to the conductor foil 4.

Incidentally, the cavity 10 may be fixed before the capacitor 21 and the inductor 25 are assembled.

Next, the support plate 28 to which the trimmer capacitor 40 is attached in advance is assembled so that the cavity internal parts 30, 30 are housed in each cavity 10, 10, and their edges rest on the mounting part 15, and fixed. The support plate 28 is integrally fixed to the cavity 10 by screwing the threaded rod 45 into the screw hole 16 through the through hole 33. As a result, the ground portion 35 is connected to the mounting portion 1.
It becomes electrically conductive (at the same potential) with the cavity 10 via the capacitor 5. Further, the coupling elements 38 and 39 in each cavity 10 are arranged side by side on both sides of the inductor 25 in a designed positional relationship as shown in FIG.

Next, cover the lid 41 so that the fastening piece 18 passes through the through hole 44, and twist and deform the portion of the fastening piece 18 that protrudes from the through hole 44.
is fixed to the cavity 10.

The filter device A is completed by the above operations.

In the case of the above configuration, a high frequency signal (for example, a UHF television signal) inputted to one terminal 36 (input terminal) via a lead wire not shown is connected to that terminal 36 within one cavity 10. is transmitted to the coupling element 38 and further to the cavity 10.
The signal is transmitted to the coupling element 39 through well-known electrical coupling between the members within. Furthermore, the signal is transmitted to the connecting conductor 37
coupling element 39 in the other cavity 10 through
is transmitted to the coupling element 38 through well-known electrical coupling of components within the cavity 10, and therethrough to the other terminal 36 (output terminal). In this way, the above signal is passed through the high frequency filter B.
In the process of passing through the filter B, a well-known filtering effect is performed, and even if there are a large number of signals input to the filter B, only signals in a predetermined band among them appear at the output terminal 36.

Next, FIG. 9, which shows a different embodiment of the present application, will be described. This figure shows an example in which the support plate 28e is further provided with other circuit conductors. In the figure, the support plate 28e is formed of an insulating plate 29e with conductive foil on both sides. The conductor foil on the back side has various conductors similar to those in the previous embodiment, while the conductor foil on the front side has ground parts 45, 45.
and a coupling degree adjusting element 46 are formed. The degree of coupling adjustment element 46 is formed at a position where it overlaps the inductor in projection when the support plate 28e is attached to the cavity.

When the device having the above structure is used by being attached to the cavity, it exhibits the characteristics shown by the two-dot chain line in FIG. 10 and can widen the band. A filter with such characteristics is conveniently used as a bandpass filter that passes a plurality of channels. Furthermore, when the adjustment element 46 and the grounding part 45 are connected by soldering at the positions indicated by numerals 47, 47, etc. in the above-mentioned state of use, the characteristic shown by the solid line in FIG. 10 is exhibited and the band is narrowed. I can do it. A filter with such characteristics is conveniently used as a bandpass filter that passes a single channel.

The adjustment element 46 has both ends connected to the ground portions 45, 4.
5, and the connected portions may be cut with a knife or the like, if desired.

It should be noted that parts that are functionally the same or equivalent to those in the previous figure are given the same reference numerals as those in the previous figure with an alphanumeric letter "e", and redundant explanations are omitted. (Also, in the following figure, the same idea is given by f and redundant explanation is omitted.) Next, Fig. 11 shows a further different embodiment of the present application, in which a larger number of filters are arranged in parallel. This figure shows an example of a filter device.

As described above, in this invention, (a) When the inductor 25 is assembled during assembly, it is done before the coupling elements 38 and 39 are assembled, so it is not necessary to assemble one inductor 25 alone. (because there is no need to mount the coupling elements 38, 39 side by side on both sides) and workability is very good (much easier than mounting three pieces side by side).

(b) Also, regarding the assembly of the cavity 10, there is an effect that the attachment can be easily carried out by the cavity alone.

(c) Furthermore, when the inductor 25 and the cavity 10 are fixed to the substrate 1, the cavity 1
0 and the inductor 25 can be positioned centering on the substrate 1, and the mutual positional relationship can be set to the designed positional relationship.

(d) Furthermore, when assembling the two coupling elements 38 and 39 so that one each is located on both sides of the inductor 25, the positional relationship of the coupling elements 38 and 39 with the cavity 10 is determined in advance. Since the supporting plate 28 is formed using printed wiring means, the connecting elements 38 and 39 can be assembled at predetermined positions simply by attaching the supporting plate 28 to the mounting portion 15 provided in the cavity 10. This also has the effect of making the assembly work extremely easy.

(e) Moreover, even if the assembly is performed individually as described above, in the assembled state, the cavity 10 and the inductor 25, the cavity 10 and both coupling elements 38 and 39, and the inductor 25 and both The positional relationship between the coupling elements 38 and 39 is determined, and there is an effect that the designed high frequency characteristics can be correctly obtained.

[Brief explanation of drawings]

The drawings show an embodiment of the present application, and FIG. 1 is a perspective view, FIG. 2 is a cross-sectional view taken along the - line, and FIG. 3 is a - line sectional view.
4 is a perspective view showing the state before the cavity is assembled, FIG. 5 is a perspective view showing the state before the support plate is assembled, FIG. 6 is a back view of the support plate, and FIG. 7 is a three-dimensional circuit diagram, FIG. 8 is an exploded perspective view of the cavity, and FIG. 9 is a perspective view showing different examples of the support plate.
FIG. 10 is a characteristic diagram, and FIG. 11 is a diagram of a multi-connected filter device in which only the support plates are separated so that the internal structure can be seen. DESCRIPTION OF SYMBOLS 1... Substrate, 10... Cavity, 25... Inductor, 28... Support plate, 38, 39... Coupling element.

Claims (1)

[Claims] 1. A high frequency filter consisting of a cavity and an internal conductor element provided in the cavity is attached to the board, and the internal conductor element has an inductor and a coupling element arranged in parallel on each side of the inductor. In the method for assembling a high frequency filter device, the substrate is provided with a cavity fixing portion and an inductor fixing portion in advance, the cavity is provided with a support plate attaching portion in advance, and the other, The above-mentioned coupling element is attached in advance by printed wiring means to the support plate formed so as to be able to be attached to the above-mentioned support plate attachment part. A method for assembling a high frequency filter device, comprising the steps of: fixing a cavity and an inductor to the respective portions; and then attaching a support plate to which the coupling element is attached to the support plate mounting portion.