JP2001210435A - Connector equipment and work method without stopping signal transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide connector equipment and work method without stopping signal transmission in which even if an end of line is in an open state, it does not give rise to total reflection, and even if a parallel operation of amplifiers is carried out, a disorder in transmission frequency is suppressed to the mini mum, in case a bypass line is prepared. SOLUTION: When the bypass line is formed through a branch connector 1 which has a branch terminal 1c being placed in connection parts of a coaxial cable or a relay apparatus, a branch adapter 2 is made to intervene between the branch terminal 1c of the above-mentioned branch connector 1 and the bypass line. A capacitor C1 and a resistance R1 which are connected in series are intervened between an input-output terminal 1a, 1b and the branch terminal 1c in the branch connector 1, and a capacitor C2 and a resistance R2 which are connected in series are connected between an input-output terminal 2a, 2b in the branch adapter 2 and a surrounding ground conductor 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a construction for checking and replacing relay equipment such as a coaxial cable and an amplifier constituting a signal line network without stopping television signals and the like during transmission. The present invention relates to a connector device for performing the method and an uninterrupted construction method using the connector device.

[0002]

2. Description of the Related Art In a CATV system, a number of repeaters such as amplifiers are connected via a coaxial cable from a center station or a head end having a receiving antenna for transmitting a television signal or the like to a receiver at each subscriber's house. I have. In such a signal line network, when performing repair, inspection, or replacement of an amplifier or the like, it is required that the signal transmitted is not interrupted so as not to disturb the subscriber. For the uninterrupted construction method, see International Publication Number W
There is a technique disclosed in O96 / 04704 republished patent publication. This is because when a connector with a branch hole is connected to a CATV device in advance and the CATV device is exchanged and maintained,
This is a construction method in which a bypass line is provided by connecting a bypass line to a branch hole of a connector with a branch hole to provide a bypass line.

[0003]

However, the above-mentioned method is a non-stop method, but by connecting a bypass line, the impedance of the line is reduced to one half of the original value and mismatching occurs. In addition, during the work of connecting the bypass cable, one end of the cable is opened, and during that time, the radio wave is totally reflected, so that the signal line is affected by ghost or the like. However, if two workers simultaneously perform the switching operation of the track, the effect of the total reflection can be minimized, but the increase in costs due to the increase in the number of workers and working equipment cannot be avoided. In addition, when a bypass line is provided in an amplifier and the two amplifiers, the main amplifier and the sub-amplifier, are temporarily operated in parallel, the frequency characteristics of the signal line are disturbed and the terminal line network is adversely affected. Had also occurred.

In view of the above problems, it is an object of the present invention to prevent total reflection even when one end of a bypass line is in an open state, and to minimize disturbance of a transmission frequency even when an amplifier is operated in parallel. It is an object of the present invention to provide a connector device and a non-stopping method using the connector.

[0005]

In order to solve the above problems, a connector device according to the present invention comprises an input terminal and an output terminal connected to a coaxial cable or a signal input / output unit of a relay device, and the input terminal or the input terminal. A branch connector having a branch terminal for branching a signal received from an output terminal;
A connector device comprising a branch adapter connected to the branch terminal, wherein the branch connector connects the center contacts of the input and output terminals and connects the center contact and the center contact of the branch terminal in series. And the branch adapter are connected via a resistor.
It has an input terminal connected to the branch connector and an output terminal connected to the coaxial cable, and connects the center contacts of the input and output terminals together, and is connected in series between the center contact and the outer conductor of the branch adapter. It is characterized in that a capacitor and a resistor are connected.

According to a second aspect of the present invention, in the connector device of the first aspect, the resistance sum of the resistance provided on the branch connector and the resistance provided on the branch adapter is substantially twice the characteristic impedance of the connection line. Features.

According to a third aspect of the present invention, in the connector device of the first or second aspect, the branch connector has a coil in parallel with both the capacitor and the resistor connected in series.

According to a fourth aspect of the present invention, there is provided an uninterrupted uninterrupted construction method in which a coaxial cable or a relay device constituting a signal line network is maintained or replaced by providing a bypass line so that a line signal is not interrupted. The method according to claim 1, wherein a line network is formed by interposing the branch connector according to claim 1 at a connection portion of the coaxial cable or the relay device, and a bypass line is provided in the coaxial cable or the relay device. A branch adapter is connected to the branch connector to form a bypass line.

According to a fifth aspect of the present invention, when the bypass line is provided in the repeater having an amplifying function, a sub-amplifier is provided in the bypass line at least 5 dB smaller than the amplification factor of the repeater. It is characterized by the following.

[0010]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 shows a branch connector 1 and a branch adapter 2 constituting the connector device of the present invention.
, Respectively, in which passive elements are mounted inside.

The branch connector 1 has an input terminal 1a, an output terminal 1b and a branch terminal 1c, and has input / output terminals 1a, 1b.
Are connected to each other, and the connected center conductor 4 and the center contact of the branch terminal 1c are connected via a capacitor C1 and a resistor R1 connected in series and connected to the capacitor C1 and the resistor R1. The coil L1 is connected in parallel. However, the capacitor C1 may be omitted.

The branch adapter 2 has an input terminal 2a and an output terminal 2b connected to the branch connector 1, the center contacts are connected, and the connected center conductor 5 and a housing (not shown) of the branch adapter. Between the capacitor C2 and the resistor R connected in series.
2 are connected. And the resistance R1 and the resistance R2 are
The sum of the resistance values is set so as to be approximately twice the characteristic impedance. When the characteristic impedance is 75Ω, for example, it is preferable that the resistance R1 is 30Ω and the resistance R2 is 120Ω.
The input, output and branch terminals of the branch connector 1 and the branch adapter 2 are coaxial cables (hereinafter referred to as cables).
Are formed, for example, with an FT-type connector. In addition, since the electrical connection between the input and output terminals is symmetric, if each terminal is formed in the same structure, either one may be the input terminal and the other is the output terminal. The capacitors C1 and C2 are elements for blocking the passage of low-frequency or direct-current current and passing high-frequency transmission signals.
What is necessary is just to select according to the frequency of a transmission signal.

FIG. 9 shows the return loss characteristics of the connector device. As shown, for example, 10M which is a frequency band generally used in a CATV system is used.
Hz to 770 MHz, a maximum of -9.5 dB, ie, V
SWR = 2 or less, the total reflection is not caused, and the influence of the reflection on the line network can be sufficiently reduced. That is, even if the line becomes open during the construction of the bypass line by connecting the cable to the branch terminal, it is possible to prevent the occurrence of a ghost due to the total reflection and the sudden change of the signal level even if the line is opened.

A procedure for carrying out maintenance and inspection of a CATV line using the above-described connector device will be described with reference to FIGS. First, FIG. 2A to FIG. 2E and FIG.
Description will be made based on the procedure explanatory diagrams of (f) to (j). A branch connector 1 having the above-described branch terminal is previously provided at each connection portion of the trunk amplifier 10 (10a, 10b) and the cable 11 or the like.
Before the cable 11 is replaced, the branch adapter 2 is connected to the branch terminal 1c of the branch connector 1 connected to the input / output terminal of the trunk amplifier 10a at the preceding stage (FIG. 1A). Next, a cable 16 having a level compensating amplifier 12 is attached in parallel with the trunk amplifier 10a in the preceding stage via the branch adapter 2, and parallel operation is performed (FIG. 2B). The output side of the front-stage trunk amplifier 10a is connected to the output-side branch connector 1 to which the cable 11 is connected.
(Fig. (C)), and one end of a new cable 13 to which the branch connector 1 is attached is connected (Fig. (D)).

Next, the branch adapter 2 is attached to the branch connector 1 of the trunk amplifier 10b at the subsequent stage (FIG. 3 (e)).
Via the branch adapter 2, a cable 16 having a level compensation amplifier 12 is attached in parallel to the trunk amplifier 10b (FIG. (F)). And the latter stage trunk amplifier 1
The input side of Ob is removed from the input side branch connector 1 to which the cable 11 is connected (FIG. (G)), and the other end of the new cable 13 attached to the preceding trunk amplifier 10a is connected (FIG. (H)). Finally, the bypass line having the first and second stage level compensation amplifiers 12 and 12 is removed together with the replaced cable 11 (FIG. (I)), and the branch adapter 2 is removed to complete the replacement of the cable (FIG. 3 (j)). )). In a normal use state in which the branch adapter is not mounted, the branch terminal of the branch connector is preferably plugged with a blind plug.

FIG. 5 shows a gain-frequency characteristic between the input and output terminals of the trunk amplifier 10 in a state where the branch connector 1 is connected and the branch adapter 2 is not provided. 6 shows the same characteristics. By attaching a branch adapter to the branch connector,
Although the line is terminated in a pseudo manner, as shown in the figure, even if a loss is generated by the branch adapter and the branch connector, the gain of the trunk amplifier does not significantly decrease. In addition, since the branch adapter is not attached during normal use, no loss occurs and lightning resistance is improved.

FIG. 7 shows a gain in a state in which the level compensation amplifier 12 is attached to the trunk amplifier 10 to perform parallel operation.
9 shows frequency characteristics. However, the gain of the level compensation amplifier is set to -10 dB of the trunk amplifier. With this setting, as shown in the figure, even when the trunk amplifier and the level compensation amplifier are operated in parallel, the ripple is approximately ±
It can be made as small as 2 dB, and the influence on the line can be made sufficiently small. In this case, when the signal flow is switched from the main amplifier (trunk amplifier) to the sub-amplifier (level compensation amplifier), the output level decreases by about 10 dB. However, the trunk amplifier usually has an AGC (auto gain control) function. Since the output level returns to the normal level by the AGC function of the trunk amplifier at the subsequent stage, there is almost no influence on the transmission path network.

The gain of the level compensation amplifier, which is a sub-amplifier, need not be -10 dB as compared with the main amplifier. If the gain is smaller than the gain of the main amplifier, an effect appears, and especially, -5 dB.
The following is effective. FIG. 8 shows the gain characteristics when the sub-amplifier has the same gain as the main amplifier, and a large ripple occurs.

Next, a procedure for replacing the trunk amplifier 10 will be described with reference to FIGS. 4 (a) to 4 (e). First, the branch connector 1 having the above-mentioned branch terminal is interposed in advance for each connection between the trunk amplifier 10 and the cable 17 or the like. Prior to the replacement of the trunk amplifier 10, the branch adapter 2 is connected to the branch output terminal 1c of the branch connector 1 connected to the input / output terminal of the trunk amplifier 10 (FIG. 1A). Next, the cable 18 having the level compensation amplifier 14 is connected in parallel to the trunk amplifier 10 and connected to the branch adapter 2 (FIG. 2B) to form a bypass line, and the trunk amplifier 10 is replaced (FIG. 2C). ). Usually, the replacement of the trunk amplifier 10 is performed by detaching the main body of the trunk amplifier 10 into a block and forming the main body 15a.
Is replaced by a new body 15b. In this case, there is no need to remove the input terminal and the output terminal of the trunk amplifier 10 from the line and replace them, but the trunk amplifier may be replaced together with the housing. Then, the bypass line having the level compensation amplifier 14 is removed (FIG. (D)), and the branch adapter 2 is removed (FIG. (E)), and the replacement of the trunk amplifier is completed.

By performing the replacement work as described above, when the level compensation amplifier 14 is mounted, the branch output terminal of the branch connector is pseudo-terminated by the branch adapter, so that reflection or ghost may occur during the replacement work. No,
The line signal does not stop.

Although the branch connector of the above embodiment has a coil between the input terminal and the branch terminal, this is for transmitting DC or low frequency power other than signals. If there is no power transmission in the road, this coil may be omitted. Further, the replacement of the cable and the replacement of the trunk amplifier may be performed simultaneously.

[0022]

As described above in detail, according to the connector device of the first aspect of the present invention, the signal line can be divided by using the branch connector for the cable of the signal line and the connecting portion of the relay device. The bypass line can be easily provided without processing the cable, and the branch adapter is connected to the branch connector when the bypass line is provided.
The adverse effect on the signal line can be reduced without causing loss due to the connector device and causing total reflection.

According to the second aspect of the invention, in addition to the effect of the first aspect of the invention, the VSWR of the branch terminal can be set to approximately 2, and the influence of reflection on the signal line can be eliminated. According to the invention of claim 3, in addition to the effect of the invention of claim 1 or 2, a direct current or a low-frequency current can be output from the branch terminal, and power can be supplied to the bypass line.

According to the uninterrupted construction method according to the fourth aspect of the present invention, the bypass line can be easily formed, and when the bypass line is formed, the state of total reflection does not occur, so that the influence on the signal line can be reduced. . According to the invention of claim 5, in addition to the effect of the invention of claim 4, even if a bypass line having an amplifier is provided in a relay device having an amplification function and a parallel operation state is established, a ripple of a transmission signal is suppressed to be small. And the effect on the signal line can be reduced.

[Brief description of the drawings]

FIG. 1 is an electrical configuration diagram of a connector device showing an example of an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a cable exchange procedure of a signal line.

FIG. 3 is an explanatory view showing a cable replacement procedure following FIG. 2;

FIG. 4 is an explanatory diagram showing a procedure for replacing a trunk amplifier on a signal line.

FIG. 5 shows gain-frequency characteristics of a trunk amplifier in an initial state without a branch adapter attached.

FIG. 6 shows a gain-frequency characteristic of a trunk amplifier with a branch adapter attached.

FIG. 7 shows a gain-frequency characteristic of a trunk amplifier in a state where a level compensation amplifier is attached in parallel to a trunk amplifier via a branch adapter.

FIG. 8 shows a frequency characteristic of the trunk amplifier in a state where a level compensation amplifier having the same gain as that of the trunk amplifier is attached in parallel to the trunk amplifier.

FIG. 9 shows return loss characteristics of the connector device of FIG. 1;

[Explanation of symbols]

1 branch connector, 1a input terminal, 1b output terminal, 1c branch terminal, 2 branch adapter, 2a
.Input terminals, 2b output terminals, 4, 5 central conductors
6, ground conductor, 10, 10a, 10b trunk amplifier, 11 coaxial cable, 12, 14, level compensation amplifier, 16, 17, 18, coaxial cable, C
1, C2 ··· condenser, R1, R2 ··· resistor, L1 ·
·coil.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Shigeki Ito 80, Noboru, Asada-cho, Nisshin-shi, Aichi Prefecture F-term (reference) 5C056 FA02 FA05 FA08 HA14 5C064 BA02 BB06 BC14 5E021 FA03 FA07 FB11 FB16 FC23 FC29 MA02 MA09 MA18 MB08

Claims (5)

[Claims] 1. A branch connector having an input terminal and an output terminal connected to a coaxial cable or a signal input / output unit of a relay device, and a branch terminal for branching a signal input from the input terminal or the output terminal, and the branch terminal. A branch adapter that connects the center contacts of the input and output terminals, and a capacitor and a resistor that connect the center contacts and the center contacts of the branch terminals in series. The branch adapter has an input terminal connected to the branch connector and an output terminal connected to the coaxial cable, and connects the center contacts of the input and output terminals to each other.
Between the center contact and the outer conductor of the branch adapter,
A connector device wherein a capacitor and a resistor connected in series are connected. 2. The connector device according to claim 1, wherein the resistance sum of the resistance provided on the branch connector and the resistance provided on the branch adapter is substantially twice the characteristic impedance of the connection line. 3. The branch connector has a coil in parallel with both a capacitor and a resistor connected in series.
The connector device as described. 4. A non-stop method in which a line signal is not stopped by providing a bypass line when a coaxial cable or a relay device constituting a signal line network is maintained or replaced.
The branch adapter according to claim 1, wherein the branch connector according to claim 1 is interposed at a connection portion of the coaxial cable or the relay device to form a line network, and the branch adapter according to claim 1 is used for branching the coaxial cable or the relay device. An uninterrupted construction method characterized by forming a bypass line by connecting to a connector. 5. The uninterruptible transmission system according to claim 4, wherein when a bypass line is provided in a relay device having an amplifying function, a sub-amplifier at least 5 dB smaller than an amplification factor of the repeater is provided in the bypass line. Wave construction method.