Cable television optical transmitter of DOCSIS4.0 system

Abstract

The utility model discloses a cable television optical transmitter of a DOCSIS4.0 system, which is characterized in that the input end of a signal monitoring circuit is connected with a radio frequency signal of a cable television bidirectional hybrid optical fiber coaxial network of the DOCSIS4.0 system, and the output end of the signal monitoring circuit is connected with the input end of a first amplifying circuit; the output end of the first amplification circuit is connected with the input end of the modulation degree control circuit, the output end of the modulation degree control circuit is connected with the input end of the second amplification circuit, and the output end of the second amplification circuit is connected with the input end of the laser circuit. The output end of the laser circuit is connected with an optical signal of a cable television bidirectional hybrid optical fiber coaxial network of a DOCSIS4.0 system; the sampling end of the second amplification circuit is connected with the input end of the radio frequency sampling circuit, the output end of the radio frequency sampling circuit is connected with one end of the microprocessor circuit, and the other end of the microprocessor circuit is connected with the modulation degree control circuit.

Description

Technical Field

[0001] The utility model relates to the technical field of cable television, in particular to a cable television optical transmitter of a DOCSIS4.0 system. Background Art

[0002] DOCSIS4.0 is a new specification of the Cable Television Standards Organization for Hybrid Fiber / Coaxial Cable (HFC) networks. DOCSIS4.0 adds a new extended spectrum function and expands the operating frequency to 1.8 GHz, which is much higher than the 1.2 GHz currently supported by DOCSIS3.1.

[0003] As an important transmission device in the bidirectional HFC network of cable TV, optical transmitters are widely used in cable TV systems. The DOCSIS3.1 optical transmitters currently used in cable TV systems will not work properly and must be replaced with DOCSIS4.0 cable TV optical transmitters.

[0004] Aiming at the problems existing in the prior art, a cable television optical transmitter of a DOCSIS4.0 system is provided. Utility Model Content

[0005] The utility model aims to provide a cable television optical transmitter for a DOCSIS 4.0 system in view of the defects of the prior art.

[0006] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0007] A cable TV optical transmitter for a DOCSIS4.0 system, comprising a signal monitoring circuit, a first amplifying circuit, a modulation control circuit, a second amplifying circuit, a laser circuit, a microprocessor circuit, and a radio frequency sampling circuit;

[0008] The input end of the signal monitoring circuit is connected to the radio frequency signal of the cable TV bidirectional hybrid fiber-coaxial network of the DOCSIS4.0 system, the output end of the signal monitoring circuit is connected to the input end of the first amplifier circuit, the output end of the first amplifier circuit is connected to the input end of the modulation index control circuit, the output end of the modulation index control circuit is connected to the input end of the second amplifier circuit, the output end of the second amplifier circuit is connected to the input end of the laser circuit, and the output end of the laser circuit is connected to the optical signal of the cable TV bidirectional hybrid fiber-coaxial network of the DOCSIS4.0 system; the sampling end of the second amplifier circuit is connected to the input end of the radio frequency sampling circuit, the output end of the radio frequency sampling circuit is connected to one end of the microprocessor circuit, and the other end of the microprocessor circuit is connected to the modulation index control circuit.

[0009] Furthermore, the signal monitoring circuit adopts the model ECJ1201-D001135.

[0010] Furthermore, the model of the first amplifier circuit is QPL1819.

[0011] Furthermore, the modulation control circuit adopts the model ARW621A.

[0012] Furthermore, the model of the second amplifier circuit 2 is QPL1821.

[0013] Furthermore, the model of the RF sampling circuit is ARW253.

[0014] Furthermore, the microprocessor circuit adopts a model of STC12C5A60S2.

[0015] Furthermore, the model of the laser circuit is BLDFB-PSA2-D55100B-2GR.

[0016] Compared with the prior art, the cable TV optical transmitter of the DOCSIS4.0 system of the utility model complies with the new specification of the cable TV standards organization for the hybrid fiber or coaxial cable (HFC) network DOCSIS4.0 standard, and is an important transmission device for the cable TV DOCSIS4.0 bidirectional HFC network. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a structural diagram of a cable TV optical transmitter of a DOCSIS4.0 system provided in an embodiment. DETAILED DESCRIPTION

[0018] The following describes the implementation of the present invention through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific implementations, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the following embodiments and features in the embodiments can be combined with each other without conflict.

[0019] The utility model aims to provide a cable television optical transmitter for a DOCSIS 4.0 system in view of the defects of the prior art.

[0020] Example

[0021] This embodiment provides a cable television optical transmitter of a DOCSIS 4.0 system. Figure 1As shown, it is installed at the front end of a cable TV bidirectional hybrid fiber-coaxial network (i.e., a bidirectional HFC network), and includes a signal monitoring circuit 1, a first amplifier circuit 2, a modulation control circuit 3, a second amplifier circuit 4, a laser circuit 5, a microprocessor circuit 6, and a radio frequency sampling circuit 7.

[0022] A signal monitoring circuit 1 is connected to the RF signal input port, the input end of the signal monitoring circuit 1 receives the input of the RF signal and is connected to the RF signal of the cable TV bidirectional HFC network of the DOCSIS4.0 system, the output end of the signal monitoring circuit 1 is connected to the input end of the first amplifier circuit 2, and the monitoring end of the signal monitoring circuit 1 can measure the level value of the input RF signal through the monitoring end; the output end of the first amplifier circuit 2 is connected to the input end of the modulation index control circuit 3, the output end of the modulation index control circuit 3 is connected to the input end of the second amplifier circuit 4, the output end of the second amplifier circuit 4 is connected to the input end of the laser circuit 5, the output end of the laser circuit 5 is the output port of the optical signal, and the output port is connected to the optical signal of the cable TV bidirectional HFC network of the DOCSIS4.0 system; the sampling end of the second amplifier circuit 4 is connected to the input end of the RF sampling circuit 7, the output end of the RF sampling circuit 7 is connected to the microprocessor circuit 6, and the control end of the microprocessor circuit 6 is connected to the modulation index control circuit 3.

[0023] The signal monitoring circuit 1 is mainly composed of a RF 120 branch circuit, using the product of Zhuhai Dongheng Electronics, model ECJ1201-D001135, with an operating frequency range of 5-1800MHz. The main circuit is connected to the first amplification circuit 2, and the branch circuit is connected to the monitoring port.

[0024] The first amplifier circuit 2 uses an amplifier chip from QORVO, USA, model QPL1819, which is a low-noise GaAspHEMT single-ended MMIC RF amplifier chip with an operating frequency range of 50-1800 MHz and a gain of 20 dB.

[0025] Modulation control circuit 3 adopts ARW621A from Shanghai Anqiwei, which is a broadband, high linearity, high precision, fast switching, bidirectional, low-cost 6-bit digital controlled attenuator designed based on silicon process for applications below 6000MHz. It has multiple attenuation state configuration functions such as serial, direct parallel and latched parallel. The input power 0.1dB compression point can reach 31dBm, the insertion loss is less than 2.5dB, the switching time is less than 275ns, the attenuation range reaches 31.5dB, and the minimum step is 0.5dB.

[0026] The second amplifier circuit 4 uses an amplifier chip from the American QORVO company, model QPL1821, which is an ultra-linear GaAs pHEMT RF amplifier. The device adopts a common source and common gate design, provides 19dB flat gain and very low distortion from 5MHz to 1800MHz, and supports the application of broadband cable TV DOCSIS 4.0 system.

[0027] The RF sampling circuit 7 uses the detector of Shanghai Anqiwei, model ARW253, which is a broadband high-dynamic logarithmic detector with a frequency range of 5-6000MHz, low power consumption, anti-static, and good temperature characteristics. It uses step-by-step approximation compression technology to accurately convert the RF input signal into the corresponding logarithmic linear output with a dynamic range of 55dB.

[0028] The microprocessor circuit 6 uses the low-power microprocessor STC12C5A60S2 of Hongjing Technology, 60K Flash, 1K EEPROM, and has high cost performance. The microprocessor circuit 6 controls the modulation degree of the optical transmitter through a digitally controlled attenuator according to the sampling data from the second amplifier circuit 4 by the RF sampling circuit.

[0029] Laser circuit 5 uses a DFB butterfly laser from Xiamen Bailai Company, model BLDFB-PSA2-D55100B-2GR, 1550nm wavelength, high linearity index, and the highest operating frequency can reach 2500MHz.

[0030] The cable TV optical transmitter of the DOCSIS4.0 system of the utility model complies with the new specification of the cable TV standard organization for the hybrid optical fiber or coaxial cable (HFC) network DOCSIS4.0 standard, and is an important transmission device for the cable TV DOCSIS4.0 bidirectional HFC network.

[0031] Note that the above are only preferred embodiments of the present invention and the technical principles used. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and that various obvious changes, readjustments and substitutions can be made by those skilled in the art without departing from the scope of protection of the present invention. Therefore, although the present invention is described in more detail through the above embodiments, the present invention is not limited to the above embodiments, and may include more other equivalent embodiments without departing from the concept of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A cable television optical transmitter for a DOCSIS4.0 system, characterized in that: It includes a signal monitoring circuit, a first amplifying circuit, a modulation control circuit, a second amplifying circuit, a laser circuit, a microprocessor circuit, and a radio frequency sampling circuit; The input end of the signal monitoring circuit is connected to the radio frequency signal of the cable TV bidirectional hybrid fiber-coaxial network of the DOCSIS4.0 system, the output end of the signal monitoring circuit is connected to the input end of the first amplifier circuit, the output end of the first amplifier circuit is connected to the input end of the modulation index control circuit, the output end of the modulation index control circuit is connected to the input end of the second amplifier circuit, the output end of the second amplifier circuit is connected to the input end of the laser circuit, and the output end of the laser circuit is connected to the optical signal of the cable TV bidirectional hybrid fiber-coaxial network of the DOCSIS4.0 system; the sampling end of the second amplifier circuit is connected to the input end of the radio frequency sampling circuit, the output end of the radio frequency sampling circuit is connected to one end of the microprocessor circuit, and the other end of the microprocessor circuit is connected to the modulation index control circuit.

2. A cable television optical transmitter for a DOCSIS 4.0 system according to claim 1, characterized in that: The model used by the signal monitoring circuit is ECJ1201-D001135.

3. A cable television optical transmitter for a DOCSIS 4.0 system according to claim 2, characterized in that: The model used by the first amplifier circuit is QPL1819.

4. A cable television optical transmitter for a DOCSIS 4.0 system according to claim 3, characterized in that: The model used in the modulation control circuit is ARW621A.

5. A cable television optical transmitter for a DOCSIS 4.0 system according to claim 4, characterized in that: The model used by the second amplifier circuit is QPL1821.

6. A cable television optical transmitter for a DOCSIS 4.0 system according to claim 5, characterized in that: The model used by the RF sampling circuit is ARW253.

7. A cable television optical transmitter for a DOCSIS 4.0 system according to claim 6, characterized in that: The model of the microprocessor circuit is STC12C5A60S2.

8. A cable television optical transmitter for a DOCSIS 4.0 system according to claim 7, characterized in that: The model of the laser circuit is BLDFB-PSA2-D55100B-2GR.

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