JP2005019496A - Distributor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a distributor that can prevent resonance even when the distributor uses an already existing case. <P>SOLUTION: The distributor 1 has a case formed by fitting a lower case 10 and an upper case 20 to each other. A circuit board 11 is contained in the lower case 10. A wave absorber 30 is provided on the circuit board 11 and, at the same time, another wave absorber is provided in the upper case 20. Consequently, the distribution loss characteristics of the distributor 1 can be improved by preventing the occurrence of resonance in the case. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a distributor capable of distributing a signal in a wide frequency band from an HF band to a BS / CS signal.
[0002]
[Prior art]
The conventional distributor includes a plurality of distribution terminals, and an input signal input from the input terminal is distributed by a distribution circuit and output to the plurality of distribution terminals. Such a distributor includes a metal case, and a circuit board in which a distribution circuit is incorporated is built in the case.
A configuration of a conventional distributor 100 is shown in FIGS. 17 is a plan view showing the appearance of the distributor, FIG. 18 is a front view showing the appearance of the distributor, FIG. 19 is a side view showing the appearance of the distributor, and FIG. FIG. 21 is a plan view showing the configuration of the lower part of the case in the distributor, FIG. 22 is a front view showing the configuration of the distributor in section, and FIG. It is a figure which shows the side view which shows a structure in a cross section.
[0003]
The distributor 100 shown in these drawings is a two-distributor, and the distributor 100 is made of a metal made by fitting and fixing the case upper part 120 to the case lower part 110 which is configured in half. Has a case. A circuit board 111 in which a distribution circuit is incorporated is built in this case. In this case, as shown in FIG. 21, the circuit board 111 is fixed to the case lower part 110 and incorporated in the case. A signal input via the input terminal 121 provided on the lower surface of the case lower part 110 is guided to the circuit board 111 and distributed by the distribution circuit, and two distribution output terminals 112a provided on the lower surface of the case lower part 110 are provided. , 112b. However, the distributor 100 is not limited to two distributions, and may be four distributions or six distributions. In this case, four or six distribution output terminals are provided on the lower surface of the case lower part 110 to output distribution outputs. Become so. The case upper portion 120 is provided with a fixing protrusion 120a for fixing the distributor 100 to a branch line or the like.
[0004]
[Problems to be solved by the invention]
By the way, in a recent distributor such as a CATV signal, it is required to distribute a high-frequency signal exceeding 2 GHz. FIG. 22 shows the frequency characteristics of the distribution loss of the distributor 100 shown in FIGS. However, the distributor 100 in this case has two distributions, and distribution loss characteristics of two distribution outputs are shown in FIG. Referring to FIG. 24, the distribution loss increases rapidly in the vicinity of 2150 MHz and 2380 MHz. The cause of this is that, as shown in FIGS. 22 and 23, the space formed by the case lower portion 110 and the case upper portion 120 is a space surrounded by a conductor, and this space operates as a cavity resonator. It is thought that it is resonating at the above frequency. In order to solve this, the size of the space formed by the case lower portion 110 and the case upper portion 120 may be set to a size that does not resonate in the operating frequency band, but then the size of the existing case must be changed. However, there is a problem that a mold for creating a case is newly required.
[0005]
Accordingly, an object of the present invention is to provide a distributor that can prevent resonance even when an existing case is used.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, a distributor according to the present invention has a conductive upper case portion formed in a half-case shape and an input terminal, and distributes an input signal from the input terminal. A conductive case that has a built-in circuit board and has a plurality of distribution output terminals to which distribution outputs of the distribution circuit are respectively output, and is fitted to the upper case portion to constitute a distributor case And a radio wave absorber for preventing resonance at least on the circuit board.
In the distributor according to the present invention, a radio wave absorber for preventing resonance may be provided inside the upper case portion.
[0007]
According to the present invention, since the radio wave absorber for preventing resonance is provided on at least the circuit board built in the case, even if the existing case is used, resonance is prevented and good over a wide band. Distribution loss characteristics can be obtained. In this case, a better distribution loss characteristic can be obtained by providing the radio wave absorber inside the upper part of the case. In this way, since the existing case can be used even if the frequency band is widened to the high frequency side and exceeds 2 GHz, the cost of the distributor can be reduced.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
The configuration of the distributor according to the embodiment of the present invention is shown in FIGS. However, FIG. 1 is a cross-sectional view showing a front view of a distributor according to the present invention, and FIG. 2 is a plan view showing a configuration of a case lower part in the distributor. The distributor according to the present invention is a two-distributor, and the external appearance thereof is the same as the conventional one, and is the same as the external appearance shown in FIGS.
As shown in these drawings, the distributor 1 according to the present invention includes a case constructed by fitting and fixing a substantially rectangular case upper part 20 to a semi-rectangular substantially rectangular case lower part 10. Have. The case lower part 10 and the case upper part 20 are made of metal such as aluminum die cast, and a circuit board 11 in which a distribution circuit is incorporated is built in the case. In this case, as shown in FIG. 2, the circuit board 11 is fixed to the lower part 10 of the case with a plurality of screws and is built in the case. On the circuit board 11, a choke coil and a ceramic capacitor constituting a distribution circuit are arranged.
[0009]
In the distributor 1, a signal input via an input terminal IN provided on the lower surface of the lower case 10 (not shown) is guided to the circuit board 11 and distributed by the distribution circuit. The distribution output is output from two distribution output terminals 12 a and 12 b provided on the lower surface of the case lower part 10. In FIG. 1, the input terminal IN is provided so as to overlap the back side of the distribution output terminal 12a. An example of the distribution circuit incorporated on the circuit board 11 is shown in FIG. In the distribution circuit which is a two-distribution circuit, an input signal input from the input terminal IN is supplied to the primary side T1 of the transformer via the capacitor C1. The center tap of the primary side T1 is connected to the center tap of the secondary side T2 of the transformer, and the distribution output distributed almost equally from the secondary side T2 via the capacitors C2 and C3 is distributed from the distribution output terminals DIV1 and DIV2. Is output. A choke coil CH for passing a DC power supply is connected between the input terminal IN and the distribution output terminal DIV1.
[0010]
The distributor 1 is not limited to two distributions and may be four distributions or six distributions. In this case, four or six distribution output terminals are provided on the lower surface of the case lower part 10 so that distribution outputs are output respectively. become. The case upper portion 20 is provided with a fixing protrusion 20a for fixing the distributor 1 to a branch line or the like.
A characteristic configuration of the distributor 1 of the present invention is that a radio wave absorber 30 is provided on the circuit board 11 as shown in FIG. 2 and a radio wave absorber 40 is provided inside the case upper part 20 as shown in FIG. This is the configuration. By providing the radio wave absorbers 30 and 40, a trap as shown in FIG. 22 does not occur in the distribution loss characteristic, and a good distribution loss characteristic can be obtained over a wide band.
[0011]
The operation of providing a radio wave absorber in the case composed of the case lower part 10 and the case upper part 20 will be described with reference to FIGS.
The frequency characteristics of the distribution loss shown in FIG. 5 are as follows. As shown in FIG. 4, an elongated rectangular wave absorber 30 is attached to a portion of the circuit board 11 where no component is disposed, and It is the distribution loss characteristic in the divider | distributor 2 when not providing. However, the distributor 2 in this case is divided into two, and the distribution loss characteristics of the two distribution outputs are shown in FIG. The radio wave absorber 30 is formed into a plate shape having a certain degree of flexibility in which, for example, ferrite powder is mixed in an elastomer, and is adhered to the circuit board 11 with a double-sided adhesive. In this case, the area ratio of the radio wave absorber 30 to the circuit board 11 is about 10%. Referring to FIG. 5, a good distribution loss characteristic is obtained in distributor 2 without an increase in distribution loss in the vicinity of 2150 MHz and 2380 MHz.
[0012]
The frequency characteristics of the distribution loss shown in FIG. 7 are obtained by attaching a long and narrow rectangular wave absorber 31 having a slightly wider width to a portion of the circuit board 11 where no components are arranged as shown in FIG. Is a distribution loss characteristic in the distributor 3 when no radio wave absorber is provided. However, the distributor 3 in this case has two distributions, and the distribution loss characteristics of the two distribution outputs are shown in FIG. The radio wave absorber 31 is a plate having a certain degree of flexibility formed by mixing ferrite powder into an elastomer, for example, and is adhered to the circuit board 11 with a double-sided adhesive. In this case, the area ratio of the radio wave absorber 31 to the circuit board 11 is about 17%. Referring to FIG. 7, similar to the distribution loss characteristic shown in FIG. 5, a good distribution loss characteristic is obtained in distributor 3 without an increase in distribution loss in the vicinity of 2150 MHz and 2380 MHz.
[0013]
The frequency characteristics of the distribution loss shown in FIG. 9 are as follows. As shown in FIG. 8, an elongated rectangular wave absorber 31 having a slightly wider width at a portion where no components are arranged on the circuit board 11 and a small area on both sides thereof. This is a distribution loss characteristic in the distributor 4 when a pair of rectangular wave absorbers 32 is attached and no radio wave absorber is provided on the upper case 20. However, the distributor 4 in this case is divided into two, and the distribution loss characteristics of the two distribution outputs are shown in FIG. The radio wave absorber 31 and the radio wave absorber 32 are, for example, plate shapes having a certain degree of flexibility formed by mixing ferrite powder into an elastomer, and are adhered to the circuit board 11 with a double-sided adhesive. In this case, the area ratio of the radio wave absorber 31 and the radio wave absorber 32 to the circuit board 11 is about 27%. Referring to FIG. 9, similar to the distribution loss characteristic shown in FIG. 5, a good distribution loss characteristic is obtained in distributor 4 without an increase in distribution loss in the vicinity of 2150 MHz and 2380 MHz.
[0014]
Further, the frequency characteristics of the distribution loss shown in FIG. 10 are distribution loss characteristics when the case upper part 20 is removed from the distributor and only the case lower part 10 is used. Since the case is open, no radio wave absorber is provided on the circuit board 11 in the lower part 10 of the case, but ideal distribution loss characteristics are obtained. However, since the distributor with the case upper part 20 removed cannot be put into practical use, the distribution loss characteristic shown in FIG. 10 is increased only for comparison. However, the distributor in this case is divided into two, and the distribution loss characteristics of the two distribution outputs are shown in FIG.
Here, referring to the distribution loss characteristics shown in FIGS. 5, 7, and 9, the characteristics are the same regardless of the area of the radio wave absorber. When comparing the distribution loss characteristics shown in FIG. 5, FIG. 7 and FIG. 9 with the distribution loss characteristics shown in FIG. 10, the loss increases slightly when the frequency exceeds 2.5 GHz, but both have almost all frequencies. The distribution loss characteristics are the same in the band. From this, the distributor of the present invention can prevent resonance in the used frequency band by sticking a long and narrow rectangular wave absorber 30 as shown in FIG. 4 to the circuit board 11. I understand. That is, it is good also as the divider | distributor 2 which abbreviate | omitted the electromagnetic wave absorber 30 in the case upper part 20. FIG.
[0015]
Next, as shown in FIG. 11, the frequency characteristics of the distribution loss shown in FIG. 12 are such that a narrow and narrow rectangular wave absorber 40 is attached to the inside of the case upper portion 20 and the circuit board 11 of the case lower portion 10 is attached. Is a distribution loss characteristic in the distributor 5 when no radio wave absorber is provided. However, the distributor 5 in this case is divided into two, and the distribution loss characteristics of the two distribution outputs are shown in FIG. The radio wave absorber 40 is formed into a plate shape having a certain degree of flexibility formed by mixing ferrite powder into an elastomer, for example, and is adhered to the inside of the case upper portion 20 with a double-sided adhesive. In this case, the area ratio of the radio wave absorber 40 to the circuit board 11 is about 6%. Referring to FIG. 12, the distribution loss slightly increases in the vicinity of 1750 MHz and 2250 MHz, but the trap drop amount is a small amount of about 0.5 dB even at 2250 MHz. That is, it can be seen that when the radio wave absorber is provided on the case upper portion 20, although less effective than when the radio wave absorber is provided on the circuit board 11, the effect of preventing resonance is achieved.
[0016]
The frequency characteristics of the distribution loss shown in FIG. 14 are as follows. As shown in FIG. 13, an elongated rectangular wave absorber 41 having a slightly wider width is attached to the inside of the case upper portion 20. This is a distribution loss characteristic in the distributor 6 when no radio wave absorber is provided. However, the distributor 6 in this case has two distributions, and the distribution loss characteristics of the two distribution outputs are shown in FIG. The radio wave absorber 41 is formed into a plate having a certain degree of flexibility in which, for example, ferrite powder is mixed in an elastomer, and is adhered to the inside of the case upper portion 20 with a double-sided adhesive. In this case, the area ratio of the radio wave absorber 41 to the circuit board 11 is about 17%. Referring to FIG. 14, the distribution loss slightly increases in the vicinity of 2100 MHz and 2300 MHz, but it is only about 0.3 dB even in the trap in the vicinity of 2300 MHz having a large drop amount. Thus, it can be seen that when the radio wave absorber is provided in the case upper portion 20, although the effect is small, the effect of preventing resonance is exerted.
[0017]
As shown in FIG. 15, the frequency characteristics of the distribution loss shown in FIG. 16 are obtained by attaching an elongated rectangular wave absorber 42 having a slightly wider width and a longer length to the inside of the case upper portion 20. This is a distribution loss characteristic in the distributor 7 in the case where the circuit board 11 is not provided with a radio wave absorber. However, the distributor 7 in this case has two distributions, and the distribution loss characteristics of the two distribution outputs are shown in FIG. The radio wave absorber 42 has a plate shape with a certain degree of flexibility formed by mixing ferrite powder into an elastomer, for example, and is adhered to the inside of the case upper portion 20 with a double-sided adhesive. In this case, the area ratio of the radio wave absorber 42 to the circuit board 11 is about 30%. Referring to FIG. 16, the distribution loss slightly increases in the vicinity of 2200 MHz, but the trap drop amount is only about 0.2 dB. As described above, when the radio wave absorber is provided in the case upper portion 20, it is possible to provide an effect of preventing resonance as it is. However, even if the area of the radio wave absorber to be attached is increased, the distribution loss characteristic is increased in area. It turns out that it does not improve in proportion.
[0018]
For the reasons described above, the distributor 1 according to the present invention is provided with the radio wave absorber 30 having the size shown in FIG. 4 on the circuit board 11 as shown in FIGS. A radio wave absorber 40 having the size shown in FIG. 11 is provided. However, the distributor of the present invention is not limited to the above-described configuration, and the radio wave absorber may be provided only on the circuit board 11 of the case lower portion 10 without providing the radio wave absorber on the case upper portion 20. Furthermore, the areas of the radio wave absorber 30 and the radio wave absorber 40 shown in FIGS. 1 and 2 may be increased.
[0019]
In the above description, the radio wave absorber is provided in the case made up of the case lower part 10 and the case upper part 20. You may make it apply | coat. Moreover, it is good also as a case lower part and case upper part which have an electromagnetic wave absorption effect | action by mixing and molding a ferrite powder in a resin material. In the above description, a distributor is used. However, a distributor that branches a part of a signal may be used instead of the distributor. Specifically, by providing a radio wave absorber to prevent resonance on the circuit board on which the branch circuit built in the switch case is built, resonance occurs even if the existing case is used in the switch. Thus, a good distribution loss characteristic can be obtained over a wide band. In addition, by providing a radio wave absorber inside the upper part of the case of the branching device, better distribution loss characteristics can be obtained.
[0020]
【The invention's effect】
As described above, the distributor of the present invention is provided with the radio wave absorber for preventing resonance on at least the circuit board built in the case, so that resonance can be prevented even if an existing case is used. Thus, it becomes possible to obtain a good distribution loss characteristic over a wide band. In this case, a better distribution loss characteristic can be obtained by providing the radio wave absorber inside the upper part of the case. In this way, since the existing case can be used even if the frequency band is widened to the high frequency side and exceeds 2 GHz, the cost of the distributor can be reduced.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a front view showing a configuration of a distributor according to an embodiment of the present invention.
FIG. 2 is a plan view showing a configuration of a distributor according to the embodiment of the present invention.
FIG. 3 is a circuit diagram showing an example of a distribution circuit in the distributor according to the embodiment of the present invention.
FIG. 4 is a plan view showing a configuration of a distributor in which a radio wave absorber having a predetermined size is provided only on a circuit board under the case.
5 is a diagram showing frequency characteristics of distribution loss in the distributor shown in FIG. 4. FIG.
FIG. 6 is a plan view showing a configuration of a distributor in which a radio wave absorber having a larger predetermined size is provided only on the circuit board under the case.
7 is a diagram showing frequency characteristics of distribution loss in the distributor shown in FIG. 6;
FIG. 8 is a plan view showing a configuration of a distributor in which a plurality of radio wave absorbers of a predetermined size are provided only on a circuit board below the case.
9 is a diagram showing frequency characteristics of distribution loss in the distributor shown in FIG.
FIG. 10 is a diagram showing frequency characteristics of distribution loss when the upper part of the case is removed from the lower part of the distributor.
FIG. 11 is a plan view showing a configuration of a distributor in which a radio wave absorber having a predetermined size is provided only at the upper part of the case.
12 is a diagram showing frequency characteristics of distribution loss in the distributor shown in FIG. 11. FIG.
FIG. 13 is a plan view showing a configuration of a distributor in which a radio wave absorber having a predetermined size that is larger only in the upper part of the case is provided.
14 is a diagram showing frequency characteristics of distribution loss in the distributor shown in FIG. 13. FIG.
FIG. 15 is a plan view showing a configuration of a distributor in which a radio wave absorber having a predetermined size that is further enlarged is provided only at the upper part of the case.
16 is a diagram showing frequency characteristics of distribution loss in the distributor shown in FIG.
FIG. 17 is a plan view showing the appearance of a conventional distributor.
FIG. 18 is a front view showing the appearance of a conventional distributor.
FIG. 19 is a side view showing the appearance of a conventional distributor.
FIG. 20 is a back view showing an appearance of a conventional distributor.
FIG. 21 is a plan view showing a configuration of a lower part of a case in a conventional distributor.
FIG. 22 is a sectional view showing a front view of the configuration of a conventional distributor.
FIG. 23 is a cross-sectional view showing a configuration of a conventional distributor.
FIG. 24 is a diagram showing frequency characteristics of distribution loss characteristics in a conventional distributor.
[Explanation of symbols]
1 Distributor, 2 Distributor, 3 Distributor, 4 Distributor, 5 Distributor, 6 Distributor, 7 Distributor, 10 Case Lower, 11 Circuit Board, 12a, 12b, 12c, 12d Distribution Output Terminal, 20 Case Upper 20a fixing protrusion, 30 radio wave absorber, 31 radio wave absorber, 32 radio wave absorber, 40 radio wave absorber, 41 radio wave absorber, 42 radio wave absorber, 100 distributor, 110 case lower part, 111 circuit board, 112a Distribution output terminal, 120 Case upper part, 120a Fixing protrusion, 121 Input terminal, C1, C2, C3 capacitor, CH choke coil, IN input terminal, DIV1, DIV2 Distribution output terminal

Claims (2)

A conductive upper case part that is in the form of a semi-plated case;
A circuit board having a built-in distribution circuit for distributing an input signal from the input terminal, and having a plurality of distribution output terminals to which distribution outputs of the distribution circuit are respectively output; A conductive case lower part that is fitted to the upper case part and constitutes a distributor case;
A distributor comprising a radio wave absorber for preventing resonance at least on the circuit board. The distributor according to claim 1, wherein a radio wave absorber for preventing resonance is also provided inside the upper case portion.

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