JPH0927974A - Data signal distributer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To attain data signal distribution with lots of distribution numbers by extracting a clock signal from digital data electric signals, converting the clock signal into an optical signal so as to supply the optical signal to a distribution gate circuit without conversion of the optical signal thereby simplifying the circuit configuration. SOLUTION: A clock extract circuit 4 extracts a clock signal from an electric input data signal and gives it to a clock supply circuit 5. The electric signal from the clock supply circuit 5 is given to a laser diode 13, in which the signal is converted into an optical signal, and it is fed to a star coupler 10. The optical signal from the star coupler 10 is distributed into plural paths by using a compact spatial optical beam and given to a clock signal input section of each gate circuit 3 having a photodiode 14, in which the optical signal is converted into an electric signal. An output data signal is obtained via the gate circuit 3. Thus, the laser diode 13, the star coupler 10 and the photo diode 14 are adopted in this way to simplify the circuit configuration considerably and the data signal distributer with lots of branched numbers is easily configured.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data signal distribution device for distributing one signal to a large number of channels when transmitting a signal, and more specifically, the device becomes complicated and large even if the number of distribution channels increases. The present invention relates to a data signal distribution device that does not change.

[0002]

2. Description of the Related Art As a method of distributing an electric digital data signal to a large number of channels, a method of distributing an electric signal using a microstrip line 1 has been conventionally devised as shown in FIG.

When the electric signal propagating through the microstrip line 1 is branched into two, a Y branch 2 is usually used as shown in FIG. In this Y-branch 2, it is necessary to perform impedance matching before and after branching in order not to generate a reflected wave.

As shown in FIG. 2, if such branches 2 are vertically connected to the gate circuit 3 in two stages and are gated by a clock signal, four outputs are provided for one input. A gate circuit can be configured. That is, four synchronized data signal outputs can be obtained from one data signal input.

To increase the number of branches in the gate circuit having the above structure, the gate circuits 3 are connected in multiple stages as shown in FIG. The configuration of this figure is an example of 16 branches.
Since the clock signal extracted from the input data signal by the clock extraction circuit 4 is distributed to each gate circuit via the clock supply circuit 5, a similar gate circuit is further required. Therefore, the whole circuit configuration becomes very redundant. Also, the skew that occurs during clock signal distribution must be detected and adjusted somewhere, and as a result of incorporating the elements that perform that function, the circuit becomes more complicated.

There is a limit to the number of branches in the gate circuit, and usually 4 or 6 branches. The clock supply circuit 5 is a circuit that supplies a clock signal that is synchronized with the clock signal of the input data signal, and can output two clock signals at the same time by utilizing the inversion of the logical sign due to the circuit configuration. it can.

[0007]

DISCLOSURE OF THE INVENTION An object of the present invention is to provide a data signal distribution which can achieve the object without increasing the size of the device without complicating the circuit structure which solves the above-mentioned conventional problems. To provide a device.

[0008]

In order to solve the above-mentioned problems, a data signal distribution device of the present invention converts a clock signal extracted and regenerated by a clock extraction circuit into an optical signal, and each gate is left as it is. It is characterized in that it can be supplied to a circuit.

That is, a data signal distribution device according to claim 1 of the present invention is a circuit for extracting a clock signal from an electric digital data signal, and an electro-optical device for converting the electric clock signal into an optical clock signal. A clock distribution circuit including a signal converter and a star coupler that further branches the optical clock signal, and an input unit in which an optical-electrical converter that receives an optical signal from the star coupler and converts the optical signal into an electric signal is arranged. It is characterized in that it has a multi-stage gate circuit in which its own gate circuits are connected in multiple stages. A data signal distribution device according to a second aspect of the present invention is the data signal distribution device according to the first aspect.
In the data signal distribution device, the optical signal supply unit including a star coupler is mounted on the first substrate, the multi-stage gate circuit is mounted on the second substrate, and the first substrate and the second substrate are provided with a space. It is characterized in that they are signal-wise coupled by a light beam.

A data signal distribution apparatus according to a third aspect of the present invention is the data signal distribution apparatus according to the second aspect,
An optical waveguide connected to the star coupler is formed on the first substrate, and an optical signal is emitted to the second substrate via the optical waveguide.

Further, a data signal distribution device according to a fourth aspect of the present invention is the data signal distribution device according to the third aspect, wherein a mirror is formed in the optical waveguide, and the optical waveguide reflected by the mirror. The first substrate is provided with a lens for condensing an optical signal therein toward the second substrate.

As one of the digital transmission systems to which the present invention is applied, as shown in FIG. 4, a clock signal is added to the beginning of a data signal, the clock is extracted at the terminal station, and then the local oscillator is turned on. It is possible to reproduce the clock signal in synchronism with the subsequent data signal. However, as described above, when the data signal is distributed by the multi-stage connection of the gate circuits, a large number of clock signals for driving each gate circuit are required as shown in FIG. However, since the number of outputs of the clock supply circuit is limited, a similar gate circuit is required to distribute the clock signal, and therefore the configuration is very complicated,
It had the drawback of being redundant.

Therefore, in the present invention, the reproduced clock signal is converted into an optical signal by the electro-optical converter (laser diode), and the optical signal is distributed to the gate circuit as it is. Then, an optical-electrical converter (photodiode) is arranged near the clock input section of the gate circuit, and the clock signal light is converted into an electric signal to be a gate signal. Since the gate signal is not a signal to be transmitted, it does not need the same quality as a data signal, so the clock signal receiving section is not required to have the functions required for an ordinary optical signal receiving circuit such as waveform shaping and output adjustment. . Also, by making the optical path length from the clock supply circuit to each gate circuit the same, it is possible to obtain synchronized outputs.

Although the clock signal is branched by the optical star coupler in the present invention, the clock signal is branched by the optical star coupler because the SN ratio of the clock signal is not directly redundant to the data signal. There is no problem even if the level drops due to. On the other hand, in the case of the data signal, the SN ratio is directly deteriorated by the branch loss.
It becomes a problem.

[0015]

Embodiments of the present invention will be described below.

(First Embodiment) In the first embodiment of the present invention, as shown in FIG. 5, a clock distribution circuit 11 using a fiber type star coupler 10 and a gate circuit 3 are provided.
And a multi-stage gate circuit 12 having 16-channel branch by multi-stage connection. In addition, in the present embodiment, the gate circuit 3 is a gate that performs an OR operation.

The clock distribution circuit 11 includes the clock extraction circuit 4 and the clock supply circuit 5, the laser diode (electric-optical converter) 13 for converting an electric signal from the clock supply circuit 5 into an optical signal, and It is composed of the star coupler 10 for branching and supplying the optical signal from the laser diode 13 into a plurality of parts.

The multi-stage gate circuit 12 has a structure similar to that of the conventional multi-stage gate circuit, except that a photodiode (PD) 14 is attached to its clock signal input portion.

The data signal distribution device shown in FIG.
By adopting the laser diode 13, the star coupler 10, and the photodiode 14, the circuit configuration is remarkably simplified as compared with the conventional data signal distribution device having the same number of branches as shown in FIG. Therefore, according to the present embodiment, it is possible to easily configure the data signal distribution device having a significantly larger number of branches than the conventional one.

(Second Embodiment) In the second embodiment of the present invention, as shown in FIG. 6, a second substrate 20 on which a gate circuit is mounted and a second substrate for supplying a clock signal by light are used. The substrates 21 are individually configured and arranged to face each other.
The space between 21 is connected by a spatial light beam. In the first substrate 20, as shown in FIG. 7, the star coupler 10 is formed on a transparent substrate, and a large number of optical waveguides 22 are arranged as branch output paths from the star coupler 10.
The beam emitting portion 2 is provided at the tip of each optical waveguide 22.
3 is formed. The star coupler 10, the optical waveguide 22, and the beam emitting unit 23 constitute an optical signal supply unit 24. Reference numeral 22 in the figure
Reference numeral a is a delay portion formed in a part of the optical waveguide 22.

As shown in FIG. 8, the beam emitting portion 23 formed on the first substrate 20 has a wedge-shaped notch forming a 45 ° inclined surface on the substrate surface at the tip of each optical waveguide 22. A mirror surface is formed on the 45 ° inclined surface, and a spherical lens 23b is fixed to the back surface of the substrate below the 45 ° mirror 23a.

Therefore, in the first substrate 20, the clock signal is supplied to the star coupler 10, the optical signal propagates in the optical waveguide 22 branched from the star coupler 10 into a large number, and the tip portions of the respective optical waveguides 22 are propagated. 45 degree mirror 23
The optical signal is bent vertically downward from the substrate surface by a, collected by the spherical lens 23b, and input to the gate circuit via the photodiode of the second substrate 21 described later.

On the second substrate 21, as shown in FIG. 9, there is formed a multi-stage gate circuit comprising one gate circuit 3 for receiving a data signal and four gate circuits 3 for respectively outputting four output signals. Has been done. A photodiode 14 is attached to one input portion of each gate circuit 3. The installation positions of these photodiodes 14 are set so as to be opposed to the beam emitting portion 23 of the second substrate 21 when the first substrate 20 and the second substrate 21 are oppositely installed. ing.

In this embodiment, since the spatial light beam is used as means for supplying the optical signal from the star coupler 10 to each gate circuit 3, the data signal distribution device can be installed in a compact space. Further, there is an advantage that the number of branches can be increased.

[0025]

According to the present invention, a clock electric signal can be converted into an optical signal and the clock signal can be supplied to the gate circuit as it is, so that the circuit can be simplified and the number of branches can be reduced by connecting the gate circuits in multiple stages. It is possible to construct a very large data signal distribution device.

[Brief description of drawings]

FIG. 1 is a schematic diagram illustrating a conventional method of distributing an electric signal using a microstrip line.

FIG. 2 is a configuration diagram of a simplest conventional data signal distribution device using a microstrip line and a gate circuit.

FIG. 3 is a configuration diagram of a conventional data signal distribution device having a large number of branches.

FIG. 4 is a schematic diagram showing a configuration of an electric signal to be transmitted.

FIG. 5 is a configuration diagram showing a first embodiment of a data signal distribution device of the present invention.

FIG. 6 is a side view showing the configuration of a second embodiment of the data signal distribution device of the present invention.

FIG. 7 is a plan configuration diagram of a first substrate that constitutes a data signal distribution device according to a second embodiment of the present invention.

FIG. 8 is an enlarged cross-sectional configuration diagram of a beam emitting portion of the first substrate.

FIG. 9 is a plan configuration diagram of a second substrate constituting the data signal distribution device according to the second embodiment of the present invention.

[Brief description of reference numerals]

 1 Microstrip line 2 Y branch 3 Gate circuit 4 Clock extraction circuit 5 Clock supply circuit 10 Star coupler 11 Clock distribution circuit 12 Multi-stage gate circuit 13 Laser diode (electrical-optical converter) 14 Photodiode (optical-electrical converter) 20 1st board | substrate 21 2nd board | substrate 22 Optical waveguide 22a Delay part 23 Beam emission part 23a 45 degree mirror 23b Spherical lens 24 Optical signal supply part

Claims (4)

[Claims] 1. A circuit for extracting a clock signal from an electric digital data signal, an electro-optical signal converter for converting the electric clock signal into an optical signal, and a star for branching the optical clock signal. A clock distribution circuit including a coupler; and a multi-stage gate circuit in which a gate circuit having an input section in which an optical-electrical converter that receives an optical signal from the star coupler and converts the optical signal is arranged is connected in multiple stages. A data signal distribution device comprising: 2. An optical signal supply unit including the star coupler is mounted on a first substrate, the multistage gate circuit is mounted on a second substrate, and the first substrate and the second substrate are spatial light. The data signal distribution device according to claim 1, wherein the data signal distribution device is signal-combined by a beam. 3. An optical waveguide connected to the star coupler is formed on the first substrate, and an optical signal is emitted to the second substrate via the optical waveguide. Item 2. The data signal distribution device according to Item 2. 4. A mirror is formed on the optical waveguide, and a lens for condensing an optical signal in the optical waveguide reflected by the mirror toward the second substrate is provided on the first substrate. The data signal distribution device according to claim 3, wherein the data signal distribution device is provided in the.