CN112564810B - Set-top transmitter circuit and set-top signal transmission method - Google Patents

Abstract

The invention discloses a top-adjustment transmitter circuit and a top-adjustment signal transmission method. The top-adjustment transmitter circuit comprises a laser driving circuit and a power supply modulation circuit, the power supply modulation circuit is connected with the laser drive circuit, and the power supply modulation circuit has a The output voltage is the power supply voltage of the laser driving circuit, and the power modulation circuit can modulate the low-speed signal to the output voltage, so as to superimpose the low-speed signal on the high-speed data in the laser driving circuit. The circuit of the top-adjusting transmitter of the invention is simple and feasible, and the low-speed management data is modulated onto the high-speed data from the level of the optoelectronic transceiver, thereby realizing the top-adjustment. The module system is integrated, and the functions required for the transmitter top adjustment are integrated to reduce the number of components required by the optical module system.

Description

A top-adjusting transmitter circuit and a top-adjusting signal transmission method

technical field

The present invention relates to the technical field of optical communication, in particular to a top-modulation transmitter circuit and a top-modulation signal transmission method.

Background technique

As an important component of optical communication network, optical module provides high-speed data communication function. With the rise of applications such as big data and 5G, optical fiber resources are becoming increasingly scarce. Therefore, in wavelength division multiplexing (WDM) systems (such as 5G fronthaul, WDM-PON), in addition to establishing high-speed data transmission channels for communication between optical modules, it is also hoped to establish a simple low-speed data transmission channel to facilitate optical modules. between channel monitoring. At present, channel monitoring mainly adopts the top-adjusting technology. The top-adjusting technology refers to superimposing a small-amplitude low-speed data signal on the transmitted high-speed data signal, so as to realize the use of low-speed data signals containing channel information, signal quality and other information to manage the channel and send and receive data. It is worth thinking about how to superimpose the low-speed signal on the high-speed data signal at the transmitting end.

Patent CN110190904A discloses a method and device for realizing optical top adjustment in a WDM PON system, which realizes optical top adjustment at the transmitting end based on optical amplifier SOA or EDFA, that is, the high-speed data optical signal output by the optical module is used as the input signal of the optical amplifier, The operating current of the optical amplifier is modulated by the control circuit, so as to realize the top adjustment. Patent CN111865409A discloses a micro-controller-based top adjustment signal transmission method, system and microcontroller, which realizes optical top adjustment based on the microcontroller, that is, uses the microcontroller in the optical module to control the current of the transmitting module of the optical transceiver Control to achieve top adjustment.

Based on optical amplifiers or based on microcontrollers, top-adjustment technology is implemented at the level of optical communication systems or optical modules. The way based on the optical amplifier requires an additional optical amplifier SOA or EDFA, as well as the management control unit, modulation unit and coupling circuit matched with it. This solution increases the cost and system complexity of the optical communication system or optical module. Based on the method of microcontroller, there is a problem of conflict between I2C communication and top adjustment signal, that is, when the optical module communicates with the host through I2C, if the data packet of the top adjustment signal arrives at this time, the data of the top adjustment signal may be lost. Bag. Although Patent 2 solves this problem, a higher-performance microcontroller is required, and the control flow complexity increases. In addition to this, microcontroller-based top-tuning technology cannot send modulated signals in real time.

How to modulate a low-speed management signal onto a high-speed optical channel with a low-cost and practical method, and is simple and convenient for developers of optical communication systems or optical modules, is an important technical problem to be solved urgently in the art.

SUMMARY OF THE INVENTION

The technical problem to be solved by the present invention is to provide a simple and feasible top-modulation transmitter circuit that modulates low-speed management data to high-speed data from the level of an optoelectronic transceiver. It adopts the following technical solutions:

In order to solve the above problems, the present invention provides a top-mounted transmitter circuit, which includes: a laser drive circuit and a power supply modulation circuit, the power supply modulation circuit is connected to the laser drive circuit, and the output voltage of the power supply modulation circuit is the The power supply voltage of the laser driving circuit, the power modulation circuit can modulate the low-speed signal to the output voltage, so as to realize the superimposition of the low-speed signal on the high-speed data in the laser driving circuit.

As a further improvement of the present invention, the laser driving circuit includes a first-level driving circuit and a second-level driving circuit, the first-level driving circuit and the second-level driving circuit are DC-coupled, and the output of the power modulation circuit The voltage is the power supply voltage of the first-stage drive circuit. When the power supply voltage of the first-stage drive circuit changes, the output common-mode voltage of the first-stage drive circuit changes, thereby changing the voltage of the second-stage drive circuit. The power supply current realizes the superposition of low-speed signals on the high-speed data in the laser drive circuit.

As a further improvement of the present invention, the laser driving circuit drives a load laser diode, and the load laser diode linearly converts the electrical signal output by the laser driver into an optical signal.

As a further improvement of the present invention, the power supply modulation circuit includes a reference voltage, an operational amplifier, a transistor, a resistor R1, and a resistor R2. The forward input terminal of the operational amplifier is connected to the reference voltage Vref, and the first input terminal of the transistor is connected to the reference voltage Vref. Connected to the power supply Vcc, the second input end of the transistor is connected to the output end of the operational amplifier, the output end of the transistor generates an output voltage, the first end of the resistor R1 is connected to the output end of the transistor, and the first end of the resistor R1 is connected to the output end of the transistor. The two terminals generate a feedback voltage and are connected to the negative input terminal of the operational amplifier, the first terminal of the resistor R2 is connected to the second terminal of the resistor R1, the second terminal of the resistor R2 is grounded, and the low-speed signal is loaded on the operational amplifier positive input or negative input.

As a further improvement of the present invention, by changing the amplitude of the input low-speed signal, the amplitude of the superimposed signal on the output voltage of the power modulation circuit can be changed, thereby changing the modulation depth of the output waveform of the laser driving circuit, thereby changing the load The modulation depth of the laser diode output optical signal.

As a further improvement of the present invention, the loop bandwidth of the feedback loop is formed by controlling the reference voltage Vref, the operational amplifier, the transistor, the resistor R1 and the resistor R2, so as to change the swing of the output waveform of the laser driving circuit, thereby changing the load The intensity of the optical signal output by the laser diode.

As a further improvement of the present invention, the transistor is a MOS transistor or a BJT transistor.

The present invention also discloses a top-modulation signal transmission method, which is applied to any of the above-mentioned top-modulation transmitter circuits, comprising:

The power modulation circuit modulates the low-speed signal to the output voltage, so that the low-speed signal is superimposed on the high-speed data in the laser driving circuit.

Beneficial effects of the present invention:

The circuit structure of the top-adjustment transmitter of the present invention is simple, and the low-speed management data is modulated to the high-speed data from the level of the photoelectric transceiver, thereby realizing the top-adjustment. The module system is integrated, and the functions required for the transmitter top adjustment are integrated to reduce the number of components required by the optical module system.

The above description is only an overview of the technical solution of the present invention, in order to be able to understand the technical means of the present invention more clearly, it can be implemented according to the content of the description, and in order to make the above and other objects, features and advantages of the present invention more obvious and easy to understand , the following specific preferred embodiments, and in conjunction with the accompanying drawings, are described in detail as follows.

Description of drawings

1 is a schematic diagram of a top-adjusting transmitter circuit in a preferred embodiment of the present invention;

2 is a schematic diagram of a laser driving circuit in a preferred embodiment of the present invention;

3 is a schematic diagram 1 of a power supply modulation circuit in a preferred embodiment of the present invention;

4 is a second schematic diagram of a power supply modulation circuit in a preferred embodiment of the present invention;

FIG. 5 is a schematic diagram of modulation bandwidth and modulation depth obtained in a preferred embodiment of the present invention.

Detailed ways

The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand the present invention and implement it, but the embodiments are not intended to limit the present invention.

The top-modulating transmitter circuit in the preferred embodiment of the present invention includes: a laser drive circuit and a power supply modulation circuit, the power supply modulation circuit is connected to the laser drive circuit, and the output voltage of the power supply modulation circuit is the power supply voltage of the laser drive circuit , the power modulation circuit can modulate the low-speed signal to the output voltage, so that the low-speed signal can be superimposed on the high-speed data in the laser driving circuit.

As shown in FIG. 1-2, optionally, the laser driving circuit includes a first-level driving circuit Stage1 and a second-level driving circuit Stage2, and a direct current between the first-level driving circuit Stage1 and the second-level driving circuit Stage2 Coupling, the output voltage Vout of the power modulation circuit is the power supply voltage of the first-stage driving circuit Stage1, and when the power supply voltage of the first-stage driving circuit Stage1 changes, the output common mode of the first-stage driving circuit Stage1 The voltage Vcm changes, thereby changing the power supply current of the second-level driving circuit Stage2, so as to realize superimposing the low-speed signal on the high-speed data in the laser driving circuit. Among them, the waveform of the low-speed signal is Wave1, the waveform of the high-speed data is Wave2, the waveform of the output voltage Vout is Wave3, and the superimposed waveform obtained at the output end of the second stage drive circuit Stage2 is Wave4, which realizes the top adjustment.

Optionally, the laser driving circuit drives a load laser diode LD, and the load laser diode LD linearly converts the electrical signal output by the laser driver into an optical signal.

Optionally, the second-stage driving circuit Stage2 includes a gm transistor, and when the output common-mode voltage Vcm of the first-stage driving circuit Stage1 changes, the current of the gm transistor changes accordingly.

As shown in FIG. 3-4, in some embodiments, the power supply modulation circuit includes a reference voltage Vref, an operational amplifier OPAMP, a transistor transistor, a resistor R1, and a resistor R2, and the forward input terminal of the operational amplifier OPAMP is connected to the reference voltage Vref is connected, the first input terminal of the transistor transistor is connected to the power supply Vcc, the second input terminal of the transistor transistor is connected to the output terminal of the operational amplifier OPAMP, the output terminal OPAMP of the transistor transistor generates the output voltage Vout, the resistor R1 The first terminal of the resistor R1 is connected to the output terminal of the operational amplifier OPAMP, the second terminal of the resistor R1 generates a feedback voltage and is connected to the negative input terminal of the operational amplifier OPAMP, and the first terminal of the resistor R2 is connected to the first terminal of the resistor R1. The two ends are connected, the second end of the resistor R2 is grounded, and the low-speed signal is loaded on the positive or negative input of the operational amplifier OPAMP. Figure 3 corresponds to the low-speed signal loaded on the negative input of the operational amplifier OPAMP, FIG. 4 corresponds to a low-speed signal loaded on the forward input terminal of the operational amplifier OPAMP.

Among them, Vout provides the power supply voltage for the first-stage driving circuit Stage1, and the operational amplifier OPAMP outputs the voltage Vmod by comparing the reference voltage Vref and the divided voltage feedback between the resistors R1 and R2, and adjusts the output voltage Vout through the output voltage Vmod.

As shown in Figure 5, by changing the input low-speed signal amplitude, the amplitude of the superimposed signal on the output voltage of the power modulation circuit can be changed, thereby changing the modulation depth of the output waveform of the laser driving circuit, and then changing the load laser diode LD For the modulation depth of the output optical signal, refer to the AdpativeAM index in the figure. The modulation depth can be adjusted by adjusting the amplitude of the low-speed signal according to the needs of the system. By controlling the reference voltage Vref, operational amplifier, transistor, resistor R1 and resistor R2 to form the loop bandwidth of the feedback loop, the swing of the output waveform of the laser driving circuit is changed, and the intensity of the output optical signal of the load laser diode LD is changed, Referring to the Adpative Date bandwidth in the figure, the impact of noise on high-speed data can be reduced by optimizing the power modulation bandwidth while meeting the rate required by the protocol. The modulation bandwidth and modulation depth are adjustable.

Optionally, the transistor transistor is a MOS transistor or a BJT transistor or the like.

A preferred embodiment of the present invention also discloses a method for transmitting a top-modulation signal, which is applied to the top-modulation transmitter circuit in the above-mentioned embodiment, and includes the following steps:

The power modulation circuit modulates the low-speed signal to the output voltage, so that the low-speed signal is superimposed on the high-speed data in the laser driving circuit.

The circuit structure of the top-adjustment transmitter of the present invention is simple, and the low-speed management data is modulated to the high-speed data from the level of the photoelectric transceiver, thereby realizing the top-adjustment. The module system is integrated, and the functions required for the transmitter top adjustment are integrated to reduce the number of components required by the optical module system.

The above embodiments are only preferred embodiments for fully illustrating the present invention, and the protection scope of the present invention is not limited thereto. Equivalent substitutions or transformations made by those skilled in the art on the basis of the present invention are all within the protection scope of the present invention. The protection scope of the present invention is subject to the claims.

Claims (4)

1. A top-adjusting transmitter circuit is characterized in that, comprising: a laser drive circuit and a power supply modulation circuit, the power supply modulation circuit is connected with the laser drive circuit, and the output voltage of the power supply modulation circuit is the output voltage of the laser drive circuit. The power supply voltage, the power modulation circuit can modulate the low-speed signal to the output voltage, so that the low-speed signal can be superimposed on the high-speed data in the laser driving circuit; The laser driving circuit includes a first-level driving circuit and a second-level driving circuit, the first-level driving circuit and the second-level driving circuit are DC-coupled, and the output voltage of the power supply modulation circuit is the first-level driving circuit The power supply voltage of the drive circuit, when the power supply voltage of the first-stage drive circuit changes, the output common-mode voltage of the first-stage drive circuit changes, thereby changing the power supply current of the second-stage drive circuit, so as to realize the low-speed signal Superimposed on the high-speed data in the laser drive circuit; The laser drive circuit drives the load laser diode, and the load laser diode linearly converts the electrical signal output by the load laser driver into an optical signal; The power supply modulation circuit includes a reference voltage Vref, an operational amplifier, a transistor, a resistor R1, and a resistor R2. The forward input terminal of the operational amplifier is connected to the reference voltage Vref, and the first input terminal of the transistor is connected to the power supply Vcc. The second input terminal of the transistor is connected to the output terminal of the operational amplifier, the output terminal of the transistor generates an output voltage, the first terminal of the resistor R1 is connected to the output terminal of the transistor, and the second terminal of the resistor R1 generates the feedback voltage and It is connected to the negative input terminal of the operational amplifier, the first terminal of the resistor R2 is connected to the second terminal of the resistor R1, the second terminal of the resistor R2 is connected to the ground, and the low-speed signal is loaded on the positive input terminal of the operational amplifier or negative input terminal; By changing the amplitude of the input low-speed signal, the amplitude of the superimposed signal on the output voltage of the power modulation circuit can be changed, thereby changing the modulation depth of the output waveform of the laser driving circuit, thereby changing the modulation of the output optical signal of the load laser diode depth. 2. The top-adjusting transmitter circuit according to claim 1, wherein the loop bandwidth of the feedback loop is formed by controlling the reference voltage Vref, an operational amplifier, a transistor, a resistor R1 and a resistor R2, thereby changing the laser drive The swing of the output waveform of the circuit changes the intensity of the output optical signal of the load laser diode. 3. The adjustable top transmitter circuit of claim 1, wherein the transistor is a MOS transistor or a BJT transistor. 4. A method for transmitting a top-modulation signal, applied to the top-modulation transmitter circuit described in any one of the above claims 1-3, characterized in that, comprising: The power modulation circuit modulates the low-speed signal to the output voltage, so that the low-speed signal is superimposed on the high-speed data in the laser driving circuit.

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