WO2020259382A1 - 光模块 - Google Patents

光模块 Download PDF

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Publication number
WO2020259382A1
WO2020259382A1 PCT/CN2020/096767 CN2020096767W WO2020259382A1 WO 2020259382 A1 WO2020259382 A1 WO 2020259382A1 CN 2020096767 W CN2020096767 W CN 2020096767W WO 2020259382 A1 WO2020259382 A1 WO 2020259382A1
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WO
WIPO (PCT)
Prior art keywords
circuit
low
pass filter
chip
filter circuit
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/CN2020/096767
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English (en)
French (fr)
Inventor
王力
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Hisense Broadband Multimedia Technology Co Ltd
Original Assignee
Hisense Broadband Multimedia Technology Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Hisense Broadband Multimedia Technology Co Ltd filed Critical Hisense Broadband Multimedia Technology Co Ltd
Priority to CN202080001541.XA priority Critical patent/CN112438027B/zh
Publication of WO2020259382A1 publication Critical patent/WO2020259382A1/zh
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
    • H04B10/40—Transceivers
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
    • H04B10/27—Arrangements for networking
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
    • H04B10/60—Receivers

Definitions

  • This application relates to the field of optical communication technology, and in particular to an optical module.
  • AMCC Auxiliary Management and Control Channel
  • optical modules can only receive and transmit high-frequency digital service signals, but cannot receive and transmit low-frequency signals.
  • the optical module in the prior art cannot receive a mixed signal that simultaneously carries a high-frequency signal and a low-frequency signal.
  • an embodiment of the present application provides an optical module including a light receiving chip, a transimpedance amplifier chip, a limiting amplifier chip, a first low-pass filter circuit, a second low-pass filter circuit, a comparison circuit, and a microprocessor;
  • the resistance amplifier chip is electrically connected to the light receiving chip, the limiting amplifier chip and the first low-pass filter circuit; the optical receiving chip outputs the first mixed frequency electrical signal to the transimpedance amplifier chip; the transimpedance amplifier chip outputs the first signal to the limiting amplifier chip 2.
  • the second low-pass filter circuit is electrically connected to the first low-pass filter circuit, the first low-pass filter circuit outputs the first low-frequency electrical signal to the second low-pass filter circuit; the first input terminal of the comparison circuit is connected to the first low-pass The filter circuit is electrically connected, the second input terminal of the comparison circuit is electrically connected with the second low-pass filter circuit, the output terminal of the comparison circuit is connected with the microprocessor, and the first low-pass filter circuit inputs the second low-frequency electrical signal to the comparison circuit; The second low-pass filter circuit inputs the decision threshold electrical signal to the comparison circuit; the comparison circuit outputs the third low-frequency electrical signal to the microprocessor.
  • an embodiment of the present application provides an optical module, including a light receiving chip, a boost mirror circuit, a transimpedance amplifier chip, a limiting amplifier chip, a first low-pass filter circuit, a second low-pass filter circuit, and a comparison circuit And a microprocessor;
  • the transimpedance amplifying chip is electrically connected to the light receiving chip and the limiting amplifying chip; the light receiving chip outputs the first mixed frequency electrical signal to the transimpedance amplifying chip; the transimpedance amplifying chip outputs the second to the limiting amplifying chip Mixed frequency electrical signals, the limiting amplifier chip outputs high-frequency electrical signals;
  • the boost mirror circuit is electrically connected to the light receiving chip and the first low-pass filter circuit; the boost mirror circuit outputs working high voltage to the light receiving chip; the boost mirror circuit
  • the image electrical signal of the first mixed frequency electrical signal is output to the first low pass filter circuit;
  • the second low pass filter circuit is electrically connected to the first low pass filter circuit, and the first low pass filter circuit
  • a low-frequency electrical signal is electrically connected with the first low-pass filter circuit, the second input terminal of the comparison circuit is electrically connected with the second low-pass filter circuit, and the output terminal of the comparison circuit is connected with the microprocessor;
  • the first low-pass filter circuit inputs the second low-frequency electrical signal to the comparison circuit;
  • the second low-pass filter circuit inputs the decision threshold electrical signal to the comparison circuit;
  • the comparison circuit outputs the third low-frequency electrical signal to the microprocessor.
  • an embodiment of the present application provides an optical module, including a light receiving chip, one end is electrically connected to a boost circuit through a voltage divider resistor, and the other end is electrically connected to a transimpedance amplifier chip to receive high and low frequency mixed optical signals;
  • the subtractive amplifier circuit receives voltage signals from both ends of the voltage divider resistor, and the output terminal is electrically connected to the input terminal of the second low-pass filter circuit; the input terminal of the second low-pass filter circuit is also electrically connected to the first input terminal of the comparison circuit. Connected, the output terminal is electrically connected with the second input terminal of the comparison circuit, and the judgment threshold electric signal is output;
  • the output end of the comparison circuit is electrically connected with the microprocessor to output low-frequency digital electric signals; the transimpedance amplifier chip is electrically connected with the limiting amplifier chip, and the limiting amplifier chip outputs high-frequency electric signals.
  • Figure 1 is a schematic diagram of the connection relationship of an optical communication terminal
  • Figure 2 is a schematic diagram of the structure of an optical network unit
  • FIG. 3 is a schematic structural diagram of an optical module provided by an embodiment of the application.
  • FIG. 4 is an exploded schematic diagram of an optical module structure provided by an embodiment of the application.
  • FIG. 5 is a schematic diagram of a (partial) exploded structure of a receiving end of an optical module according to an embodiment of the application;
  • Figure 6 is a partial enlarged view of area A in Figure 5;
  • Fig. 7 is a partial enlarged view of area B in Fig. 5;
  • FIG. 8 is a schematic diagram of another structure of an optical module provided by an embodiment of the application.
  • FIG. 9 is a schematic diagram of the circuit connection of the optical module shown in FIG. 8;
  • FIG. 10(A) is a schematic diagram of a related circuit structure of a subtractive amplifier circuit provided by an embodiment of the application;
  • FIG. 10(B) is a schematic diagram of a related structure of a low-pass amplifier circuit provided by an embodiment of the application.
  • Fig. 11(A) is a schematic diagram of voltage signal conversion realized by the circuit in Fig. 10(A);
  • Fig. 11(B) is a schematic diagram of voltage signal conversion realized by the circuit in Fig. 10(B);
  • FIG. 12 is a schematic structural diagram of a second low-pass filter circuit provided by an embodiment of this application.
  • FIG. 13 is a schematic diagram of voltage signal conversion realized by the circuit in FIG. 12;
  • FIG. 14 is a schematic structural diagram of a comparison circuit provided by an embodiment of the application.
  • FIG. 15 is a schematic diagram of voltage signal conversion of the comparison circuit in FIG. 14.
  • Optical communication realizes the transmission of signals using two different carriers, electric and optical.
  • Optical fiber communication uses information-carrying optical signals to be transmitted in optical waveguides, and the passive transmission characteristics of light in optical fibers and other optical waveguides can achieve low-cost, low-loss information transmission; while computers and other information processing equipment use electrical signals. This requires the mutual conversion of electrical and optical signals in optical fiber communication systems.
  • Figure 1 is a schematic diagram of the connection relationship of an optical communication terminal.
  • the connection of an optical communication terminal mainly includes an optical network unit 100, an optical module 200, an optical fiber 101 and a network cable 103;
  • One end of the optical fiber is connected to the remote server, and one end of the network cable is connected to the local information processing equipment.
  • the connection between the local information processing equipment and the remote server is completed by the connection of the optical fiber and the network cable; and the connection between the optical fiber and the network cable is performed by the optical network with optical modules The unit is complete.
  • the optical port of the optical module 200 is connected to the optical fiber 101 to establish a bidirectional optical signal connection with the optical fiber; the electrical port of the optical module 200 is connected to the optical network unit 100 to establish a bidirectional electrical signal connection with the optical network unit; the optical module implements optical signals And electrical signals, so as to establish a connection between the optical fiber and the optical network unit; specifically, the optical signal from the optical fiber is converted into an electrical signal by the optical module and then input to the optical network unit 100. The electrical signal is converted into an optical signal by the optical module and input into the optical fiber.
  • the optical module 200 is a tool for realizing the mutual conversion of photoelectric signals and does not have the function of processing data. During the above photoelectric conversion process, the information has not changed.
  • the optical network unit has an optical module interface 102, which is used to connect to the optical module and establish a two-way electrical signal connection with the optical module; the optical network unit has a network cable interface 104, which is used to connect to a network cable and establish a two-way electrical signal connection with the network cable;
  • the connection between the module and the network cable is established through the optical network unit.
  • the optical network unit transmits the signal from the optical module to the network cable, and transmits the signal from the network cable to the optical module.
  • the optical network unit acts as the upper computer of the optical module to monitor the optical module. work.
  • the remote server establishes a two-way signal transmission channel with the local information processing equipment through optical fibers, optical modules, optical network units and network cables.
  • Common information processing equipment includes routers, switches, electronic computers, etc.; the optical network unit is the upper computer of the optical module, which provides data signals to the optical module and receives data signals from the optical module.
  • the common optical module upper computer also has an optical fiber path. Terminal etc.
  • FIG 2 is a schematic diagram of the optical network unit structure. As shown in Figure 2, there is a circuit board 105 in the optical network unit 100, and a cage 106 is provided on the surface of the circuit board 105; an electrical connector interface is provided in the cage 106 for accessing optical module electrical ports such as golden fingers; A heat sink 107 is provided on the cage 106, and the heat sink 107 has a convex structure such as fins to increase the heat dissipation area.
  • the optical module 200 is inserted into the optical network unit. Specifically, the electrical port of the optical module is inserted into the electrical connector in the cage 106, and the optical port of the optical module is connected to the optical fiber 101.
  • the cage 106 is located on the circuit board and wraps the electrical connectors on the circuit board in the cage; the optical module is inserted into the cage, and the optical module is fixed by the cage. The heat generated by the optical module is conducted to the cage through the optical module housing, and finally passes through the cage.
  • the radiator 107 is diffused.
  • FIG. 3 is a schematic structural diagram of an optical module provided by an embodiment of the application
  • FIG. 4 is an exploded schematic diagram of an optical module structure provided by an embodiment of the application.
  • the optical module provided by the embodiment of the application is 200 includes an upper housing 201, a lower housing 202, an unlocking handle 203, a circuit board 300, a light emitting sub-module 301, and a light receiving sub-module 400.
  • the upper housing 201 and the lower housing 202 form a wrapping cavity with two openings.
  • the two openings can be two openings (204, 205) at the same end of the optical module, or at two different ends of the optical module. Openings; one of the openings is the electrical port 204, which is used to insert the optical network unit and other upper computers, and the other is the optical port 205, which is used for external optical fiber access to connect the internal optical fiber, the circuit board 300, the optical transmitting sub-module 301 and Optoelectronic devices such as the light receiving sub-module 400 are located in the package cavity.
  • the upper shell and the lower shell are generally made of metal materials, which is conducive to electromagnetic shielding and heat dissipation; the assembly method of the upper shell and the lower shell is used to facilitate the installation of circuit boards and other components into the shell. Generally, the optical module will not be installed.
  • the shell is made into an integral structure, so that when assembling circuit boards and other devices, positioning components, heat dissipation and electromagnetic shielding structures cannot be installed, and it is not conducive to production automation.
  • the unlocking handle 203 is located on the outer wall of the cavity/lower housing 202. Pulling the end of the unlocking handle can make the unlocking handle move relative to the outer wall surface; when the optical module is inserted into the upper computer, the unlocking handle fixes the optical module in the cage of the upper computer. By pulling the unlocking handle to release the engagement relationship between the optical module and the host computer, the optical module can be withdrawn from the cage of the host computer.
  • the circuit board is located in a wrapping cavity formed by an upper shell and a shell, and electrical devices such as chips, capacitors and resistors are arranged on the circuit board. Choose the chip that needs to be set according to the needs of the product. Common chips include microprocessor MCU, clock data recovery chip CDR, laser drive chip, transimpedance amplification TIA chip, limiting amplification LA chip, power management chip, etc.
  • the transimpedance amplifying chip is closely related to the light receiving chip, and the short-distance and short trace design can ensure good received signal quality.
  • the transimpedance amplifying chip and the light receiving chip are packaged together in a separate package , Such as packaged in the same coaxial package TO or the same square cavity; independent package body is independent of the circuit board, the light receiving chip and the stepped amplifying chip are electrically connected to the circuit board through the independent package body; the other part of the optical module
  • a separate packaging body may not be used, but the light receiving chip and the transimpedance amplifying chip are arranged on the surface of the circuit board.
  • the light receiving chip can also be packaged independently, and the transimpedance amplifier chip is arranged on the circuit board, and the quality of the received signal can also meet some relatively low requirements.
  • the chip on the circuit board can be an all-in-one chip.
  • the laser driver chip and the MCU chip can be fused into one chip, or the laser driver chip, the limiting amplifier chip and the MCU can be fused into one chip.
  • the chip is an integrated circuit, but The function of each circuit does not disappear because of the collection, but the circuit form is integrated. Therefore, when the circuit board is equipped with three independent chips: MCU, laser drive chip and limiter amplification chip, this is the same as setting a single chip with three functions in one on the circuit.
  • the end surface of the circuit board is provided with golden fingers, which are composed of independent pins.
  • the circuit board is inserted into the electrical connector in the cage, and the golden fingers establish electrical connection with the upper computer.
  • the circuit board is the carrier of the main electrical components of the optical module.
  • the electrical components not provided on the circuit board are finally electrically connected to the circuit board.
  • the electrical connector on the circuit board realizes the electrical connection between the optical module and the upper computer.
  • the electrical connector usually used in the optical module is a golden finger.
  • the optical module also includes an optical emission sub-module and an optical receiving sub-module.
  • the optical emission sub-module and the optical receiving sub-module can be collectively referred to as an optical sub-module.
  • FIG. 4 is an exploded view of the optical module structure provided by the embodiment of the application. As shown in FIG. 4, the optical module provided by the embodiment of the present application includes an optical emission sub-module 301 and an optical receiving sub-module 400. The optical emission sub-module and the optical receiving sub-module The modules are staggered on the surface of the circuit board, which helps to achieve a better electromagnetic shielding effect.
  • the light emitting sub-module 301 is arranged on the surface of the circuit board 300.
  • the light emitting sub-module is packaged independently, physically separated from the circuit board, and electrically connected through a flexible board;
  • the receiving sub-module 400 is arranged on the surface of the circuit board 300.
  • the light receiving sub-module is independently packaged, physically separated from the circuit board, and electrically connected through a flexible board.
  • a low-frequency signal is superimposed on a high-frequency signal, and two signals of different frequencies are transmitted through the same wavelength of light; for example, based on high-frequency signals such as 10Gbps or 25Gbps
  • high-frequency signals such as 10Gbps or 25Gbps
  • high-frequency signals such as 10Gbps or 25Gbps are normal business signals.
  • add another 50Kbps low-frequency signal to perform other functions.
  • For the transmitting end of the optical module it is necessary to send out dual-frequency optical signals; for the receiving end of the optical module, it is necessary to receive dual-frequency optical signals, and then the signals of different frequencies in the optical signal are demodulated separately to obtain high-frequency signals and Low frequency signal.
  • the low-frequency receiving circuit uses the response current of the optical receiving chip to demodulate the low-frequency signal. After the light receiving chip receives the light, it will induce a response current, which is an analog current signal; the current signal is converted into a voltage signal, and then it is divided into two paths through low-pass filtering and operational amplifier amplification.
  • the low-pass filter takes its DC component and compares it with another channel through a comparator to demodulate a digital signal that can be quickly processed by the MCU. When the MCU is processing digital signals, it can quickly identify 1 or 0 to speed up the processing speed.
  • the receiving end of the optical module includes a light receiving chip, a transimpedance amplification chip TIA, a limiting amplification chip LA, a low-pass filter unit, a comparison circuit and a microprocessor.
  • the essence of the chip is the integration of the circuit, the circuit can be integrated into the chip, and some functions in the chip can also be realized by the circuit on the circuit board.
  • the function of the chip can be realized by the chip, by the circuit, or by the main chip combined with the peripheral circuit. Different functions can also be integrated by the same chip, and the change of the circuit integration form still falls within the protection scope of this application.
  • the light receiving chip, the limiting amplification chip, the low-pass filter unit (the low-pass filter unit includes a first low-pass filter circuit and a second low-pass filter circuit), a comparison circuit, and
  • the microprocessor is arranged on the surface of the circuit board. Due to the limited area of the circuit board, the above-mentioned circuits and microprocessors are arranged on the same side surface of the circuit board according to layout requirements, and can be distributed on different side surfaces of the circuit board.
  • the electrical signal is processed by a circuit. Since the electrical signal from the light receiving chip or the electrical signal from the mirror circuit is generally small, an amplifier circuit is usually added to the circuit to increase the signal strength.
  • the embodiment of the present application combines the amplifier function with the first low-pass The filter circuit is fused, and a low-pass amplifier circuit is used, and the following takes the low-pass amplifier circuit as an example.
  • the light receiving chip, the limiting amplifier chip, the subtractive amplifier circuit, the low-pass filter unit (the low-pass filter unit includes the second low-pass filter circuit), the comparison circuit and the micro-processing in the optical module
  • the circuit board is arranged on the surface of the circuit board. Due to the limited area of the circuit board, the above-mentioned circuit and the microprocessor are arranged on the same side surface of the circuit board according to the layout requirements, and can be distributed on different side surfaces of the circuit board.
  • the electrical signal is processed by a circuit. Since the electrical signal from the light receiving chip or the electrical signal from the mirror circuit is generally small, an amplifying circuit is usually added to the circuit to increase the signal strength.
  • the embodiment of the application adopts the amplifying function in the subtractive amplifying circuit Improve the signal strength, while the subtraction amplifier circuit still removes the noise signal.
  • the light receiving chip of the optical module can be independently arranged in a coaxial package, the limiting amplifier chip is preferably packaged with the light receiving chip in a coaxial package, a low-pass amplifier circuit or a subtractive amplifier circuit
  • the second low-pass filter circuit, the comparison circuit and the microprocessor are arranged on the surface of the circuit board, and the coaxial package is electrically connected to the circuit board.
  • the specific electrical connection method may be a flexible circuit board.
  • the essence of the chip is the integration of the circuit, and the specific shape change of the circuit does not affect the protection scope of the embodiment of the present application.
  • the embodiment of the present application uses a specific product solution as an example.
  • FIG. 5 is a schematic diagram of a (partial) exploded structure of a receiving end of an optical module according to an embodiment of the application.
  • the optical module provided in the embodiment of the present application includes a circuit board 300 and a light receiving end 400.
  • the light receiving end 400 is arranged on the surface of the circuit board 300.
  • the light receiving end 400 includes a light receiving chip 401, an optical waveguide 402, a cover plate 403, a transimpedance amplification chip 500 and a limiting amplification chip 600.
  • the surface of the circuit board 300 has a gold finger 303.
  • the light receiving chip, the transimpedance amplifying chip and the limiting amplifying chip are respectively arranged on the surface of the circuit board to realize electrical connection with the circuit board; the cover plate 403 covers the light receiving chip, the transimpedance amplifying chip, the limiting amplifying chip and the optical waveguide The surface of the circuit board.
  • FIG. 6 is a partial enlarged view of the area A in FIG. 5, the area A includes the optical waveguide 402, the light receiving chip 401, and the transimpedance amplifier chip TIA 500.
  • the light receiving chip 401 is arranged on the surface of the circuit board 300, the optical waveguide 402 is located above the light receiving chip 401, the photosensitive surface of the light receiving chip 401 faces the optical waveguide 402, and the light carrying the mixed frequency signal passes through the optical waveguide 402. It is transmitted to the light receiving chip 401, specifically, the end surface of the optical waveguide 402 is an inclined surface, and the light is reflected at the inclined surface of the optical waveguide 402, and then enters the photosensitive surface of the light receiving chip.
  • the light receiving chip is a chip for receiving light signals at the receiving end of the optical module. After the light carrying the dual-frequency mixed signal enters the photosensitive surface of the light receiving chip, the light receiving chip uses the photoelectric conversion effect to generate a current signal, and the current carries the mixed frequency signal In the process of converting light into electric current, the carrier of the signal changes, but the information remains unchanged.
  • the signal output by the light receiving chip is usually an analog signal, and the common light receiving chip is a PIN photodiode or a photoelectric avalanche diode APD.
  • the first mixed-frequency electrical signal (specifically, photocurrent) generated by the light receiving chip is transmitted to the transimpedance amplifier chip.
  • the photocurrent generated by the light receiving chip includes high-frequency and low-frequency signals.
  • the photocurrent needs to be divided into at least two parts.
  • a mirroring circuit is used to mirror the photocurrent.
  • the current generated after mirroring can be one, two or more.
  • the transimpedance amplifying chip matched with the PIN photodiode has a current output terminal 501 and a photovoltage output terminal (502, 503), and the output of the current output terminal 501 is the same as that of the light receiving chip
  • the current is used for subsequent low-frequency signal reception;
  • the photovoltage output terminals (502, 503) output the photovoltage converted by the photocurrent;
  • the limiting amplifier chip has a first mirror circuit, which mirrors the photocurrent from the light receiving chip, and outputs the mirrored current through the current output terminal to achieve the output of the third mixed frequency electrical signal for subsequent use Low frequency signal reception; the photocurrent from the light receiving chip is used for subsequent high frequency signal reception.
  • the photocurrent from the light receiving chip is the most primitive current, and is preferentially used for the demodulation of high-frequency signals to ensure the quality of service data.
  • the mirrored current is the same as the photocurrent, the mirroring can also be The resulting current is used for high frequency signal reception, and the photocurrent is used for low frequency signal reception.
  • the transimpedance amplifier chip can also integrate a conversion circuit to convert the current used for low-frequency signal reception into a voltage signal;
  • the first mirror circuit in the optical module can mirror two mirror currents, one is used for demodulation of low-frequency or high-frequency signals, and the other is used to realize the function of receiving optical power intensity detection.
  • the received optical power intensity RSSI detection circuit is generally composed of a grounding resistance and a microprocessor.
  • the other mirror current is converted into a voltage signal by the grounding resistance and then input into the microprocessor.
  • the microprocessor samples the received optical power intensity signal;
  • the first mirror circuit can be arranged in the transimpedance amplifying chip TIA, or can be arranged outside the transimpedance amplifying chip on the circuit board.
  • the mirror current can be directly output by the mirror circuit; it can also be connected to the transimpedance amplifier chip and output from the current output terminal of the transimpedance amplifier chip;
  • the photocurrent signal After entering the transimpedance amplifier chip, the photocurrent signal is amplified and converted into a voltage signal.
  • the voltage signal is output from the transimpedance amplifier chip to realize the output of the second mixed frequency electrical signal.
  • the second mixed frequency electrical signal is preferably output in the form of a differential voltage signal. Two output ports (502, 503) are required;
  • the transimpedance amplifier chip matched with the APD photoelectric avalanche diode has a photovoltage output terminal (502,503), and the photovoltage output terminal (502,503) outputs a photocurrent
  • the converted photovoltage is preferably output in a differential form.
  • a boost circuit is added to the optical module, and the boost circuit is used to provide high voltage for the APD; in order to facilitate the reception of photocurrent, a second is added to the optical module.
  • Mirror circuit The boost circuit is connected to the APD through a path in the mirror circuit. The current in this path is the photocurrent generated by the APD. The current in this path is used for subsequent high-frequency signal reception; the second mirror circuit uses this path The current in the photocurrent is mirrored to obtain the mirror current of the photocurrent.
  • the third mixed frequency electrical signal is specifically represented as the mirror current; the mirror current is used for subsequent low-frequency signal reception.
  • the photocurrent from the light receiving chip is the most primitive current, and is preferentially used for the demodulation of high-frequency signals to ensure the quality of service data.
  • the mirroring can also be The obtained current is used for high frequency signal reception, and the original current is used for low frequency signal reception.
  • a conversion circuit may also be integrated in the second mirror circuit to convert the current used for receiving low-frequency signals into voltage signals;
  • the second mirror circuit in the optical module can mirror two mirror currents, one is used for demodulation of low-frequency or high-frequency signals, and the other is used to realize the function of detecting received optical power intensity.
  • the received optical power intensity RSSI detection circuit is generally composed of a grounding resistance and a microprocessor.
  • the other mirror current is converted into a voltage signal by the grounding resistance and then input into the microprocessor.
  • the microprocessor samples the received optical power intensity signal;
  • the booster circuit can be arranged in the transimpedance amplifier chip or on the circuit board, and its appearance can be a chip or a circuit, or a main chip combined with a peripheral circuit;
  • the second mirror circuit may be provided in the transimpedance amplifier chip or on the circuit board, and its presentation form may be a chip or a circuit, or a main chip combined with a peripheral circuit.
  • the photocurrent signal enters the transimpedance amplifying chip and is amplified and converted into a voltage signal.
  • the voltage signal is output from the transimpedance amplifying chip to realize the output of the second mixed frequency electrical signal.
  • the voltage signal is preferably output in a differential form.
  • the signal related to the photocurrent can be directly obtained on the circuit connecting the booster circuit and the APD for the reception of low-frequency signals.
  • Fig. 7 is a partial enlarged view of area B in Fig. 5.
  • the limiting amplifier chip 600 is disposed on the circuit board 300, and the limiting amplifier chip TIA is connected to the transimpedance amplifier chip LA for receiving optical voltage signals.
  • the limiting amplifier chip further amplifies the photovoltage signal and limits it to the set output differential amplitude, and the voltage signal output from the limiting amplifier chip is a high-frequency signal.
  • the limiting amplifier chip has input ports (601, 602) to receive photovoltage signals (differential photovoltage signals) from the transimpedance amplifier chip, and the limiting amplifier chip has output ports (603, 604) to output high-frequency signals.
  • the golden fingers on the circuit board 300 have pins 605 and 606, and high-frequency signals are output to the host computer through the pins 605 and 606.
  • On both sides of the pins 606 and 606 for transmitting high frequency signals there are ground pins 607 and 608, and the ground pins are used to realize electrical isolation of the pins for transmitting high frequency signals.
  • a capacitor is connected between the limiting amplifier chip and the transimpedance amplifier chip.
  • the transimpedance amplifier chip outputs two differential signals.
  • the first capacitor connects one of the differential signals to the first input terminal of the limiting amplifier chip
  • the second capacitor connects the other of the differential signals to the first input terminal of the limiting amplifier chip.
  • Two input terminals; the limiting amplifier chip combines the first capacitor and the second capacitor to perform high-pass filtering on the voltage signal output by the transimpedance amplifier chip to output a high-frequency signal.
  • limiting amplifier chips In addition, in practical applications, the design of limiting amplifier chips is generally aimed at high-frequency electrical signals, because optical fiber communication services are high-rate and ultra-high-rate signal transmission, and limiting amplifier chips cannot simultaneously handle mixed frequency signals with such a large frequency difference. Receiving, the limiting amplifier chip generally only recognizes the high frequency part of the electrical signal.
  • the first capacitor, the second capacitor, and the pull-up resistor integrated inside the limiting amplifier chip form a high-pass filter.
  • the low frequency signal therein is Filter out to achieve high-pass filtering.
  • FIG. 8 is a schematic diagram of another structure of the optical module provided by an embodiment of the application
  • FIG. 9 is a schematic diagram of circuit connection of the optical module shown in FIG. 8.
  • Figure 5 shows one side surface of the circuit board
  • Figure 8 shows the other side surface of the circuit board. Due to the limited space on the circuit board surface, the chips on the circuit board are respectively arranged on the upper and lower surfaces of the circuit board.
  • FIG. 8 shows the positions of some circuits/chips on the optical module circuit board, specifically including a subtractive amplifier circuit 700, a second low-pass filter circuit 800, a comparison circuit 900, and a microprocessor MCU304.
  • the electrical connections between the related circuits/chips in FIG. 8 are shown in FIG. 9. As shown in FIG.
  • the subtractive amplifier circuit 700, the second low-pass filter circuit 800, the comparison circuit 900 and the microprocessor 304 are arranged on the surface of the circuit board, and the subtractive amplifier circuit 700 is respectively connected to the second low-pass filter circuit 800 and the comparison circuit 900 is connected, the second low-pass filter circuit is connected to the comparison circuit 900, and the comparison circuit is connected to the microprocessor MCU304.
  • one end of the photoelectric avalanche diode APD is connected to the boost circuit Vapd through a voltage divider resistor R, and the other end is connected to the transimpedance amplifier chip TIA. Since the voltage divider resistor R and TIA are connected in series at both ends of the APD, the current flowing through the voltage divider R is the same as the current flowing into the TIA. Collecting the voltage signal across the voltage divider resistor can obtain the photovoltage signal corresponding to the photocurrent. Used for the reception of low-frequency signals; the current signal flowing into the TIA is used for the reception of high-frequency signals.
  • the current or voltage used for receiving low-frequency signals is connected to the subtraction amplifier circuit.
  • the subtractive amplifier circuit takes the operational amplifier main chip combined with the peripheral circuit as an example, and the low-frequency signal takes the voltage signal as an example.
  • FIG. 10(A) is a schematic diagram of a related circuit structure of a subtractive amplifier circuit provided by an embodiment of the application.
  • the subtraction amplifier circuit 700 includes a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, and an operational amplifier 701.
  • the voltage divider resistor R connected between the boost circuit Vapd and the photoelectric avalanche diode has two ends of M1 and M2, one end of the first resistor R1 is connected to M1, and the other end is connected to the first input end of the operational amplifier; one end of the third resistor R3 Connect to M2, and connect the other end to the second input of the operational amplifier.
  • a grounded second resistor R2 is connected between the first resistor and the first input terminal of the operational amplifier, one end of the fourth resistor is connected between the third resistor and the second input terminal of the operational amplifier, and the other end of the fourth resistor is connected to The output terminal of the operational amplifier is connected.
  • the above-mentioned subtractive amplifying circuit is a commonly used subtractive amplifying circuit in textbooks.
  • the first resistor R1 and the third resistor R3 may have the same resistance value, and the second resistor R2 and the fourth resistor R4 may also have the same resistance value.
  • many other types of circuits can be improved, and there are other types of subtractive amplifier circuits provided in textbooks.
  • the voltage at M1 and M2 are different, but the signal is the same, that is, the M1 and M2 have the same signal, but the signal amplitude is different.
  • noise signals in the signal there are noise signals in the signal.
  • One of the main functions of the subtractive amplifier circuit is to remove noise. The noise amplitude comes from the introduced noise in the circuit, and the noise amplitude at M1 and M2 is equal.
  • the amplitude of the high and low frequency signal at M1 is obviously greater than the amplitude of the high and low frequency signal at M2, but the high and low frequency signals at the two places are the same, so the high and low frequency signal at M1 subtracts the high and low frequency signal at M2, and the subtraction results in the same as that at M1 High and low frequency signal, but the amplitude of the high and low frequency signal is relatively reduced.
  • the amplitude of the noise signal at M1 is slightly the same as that at M2, but the noise signals at the two places are the same. Therefore, the noise signal at M1 is subtracted from the noise signal at M2, and the subtraction results in the same noise signal as at M1. , But the amplitude of the noise signal is significantly reduced, achieving a noise removal effect.
  • the noise signal is removed, a larger high and low frequency signal is obtained, and the signal-to-noise ratio of the signal is improved.
  • capacitors are connected between M1 and the first resistor, and between M2 and the third resistor.
  • the characteristic of passing AC and DC resistance blocks the DC high voltage output by the booster circuit, and the AC signal passes through the capacitor smoothly to be connected to the subtractive amplifier circuit. After using capacitors to isolate DC, the voltage range of AC signals will often reach below 0V.
  • the low frequency signal increases the signal amplitude after being amplified, and the signal becomes smaller after noise subtraction. Even after passing through the amplifier, it will increase the difference with the low frequency effective signal, and the signal-to-noise ratio is effective Promote.
  • Fig. 11(A) is a schematic diagram of voltage signal conversion realized by the circuit in Fig. 10(A).
  • M1 and M2 have the same high and low frequency signal data and noise signal noise, but the high and low frequency signal amplitude at M1 is greater than the high and low frequency signal amplitude at M2, and the noise signal at M1 is The noise signal at M2 is equivalent; after the subtraction amplifier circuit, the noise signal is subtracted and eliminated. After the high and low frequency signals are subtracted, the signal amplitude becomes smaller, and after amplification, the amplitude becomes larger, and finally a high and low frequency signal with improved signal-to-noise ratio is obtained.
  • the signal Before the signal enters the subtractive amplifier circuit, it can be filtered out of high frequency to retain low frequency signals and noise signals. Therefore, the above processing for high and low frequency signals can also be processing for low frequency signals.
  • this part of the subtractive amplifier circuit 700 can be replaced with a low-pass amplifier circuit.
  • the mirror current provided by the mirror circuit is used as an example.
  • the current used for receiving low-frequency signals is connected to one end of the grounding resistor, and the other end of the grounding resistor is grounded.
  • One end of the grounding resistor is also connected to the low-pass amplifier circuit through grounding.
  • the resistor R2 converts the current into voltage and then inputs it into the low-pass amplifier circuit.
  • FIG. 10(B) is a schematic diagram of a related structure of a low-pass amplifier circuit provided by an embodiment of the application.
  • the low-pass amplifier circuit takes the main chip combined with the peripheral circuit as an example, and the low-frequency signal takes the current signal as an example.
  • the low-pass amplifier circuit includes a main operational amplifier chip 702, peripheral resistors RD, RE, and a peripheral capacitor CD.
  • the main operational amplifier chip combines resistors RD and RE to form a filter amplifier circuit. Specifically, one end of the resistor RD is grounded, and the other end is connected to the operational amplifier.
  • One end of the capacitor CD is connected to the input pin IN- of the main operational amplifier chip, and the other end is connected to the output pin OUT of the main operational amplifier chip.
  • the main operational amplifier chip also includes power supply pins V+, V- and an enable pin SD; the power supply pin is used to power the main operational amplifier chip, and the enable pin is a switch pin of the main operational amplifier chip.
  • the low-pass amplifier circuit amplifies the received voltage signal and filters out the high-frequency signal part, leaving only the amplified low-frequency signal part.
  • Fig. 11(B) is a schematic diagram of voltage signal conversion realized by the circuit in Fig. 10(B).
  • the voltage signal connected to the low-pass amplifier circuit is an analog signal, including a DC part a and an AC part b.
  • the intensity of the DC part is not uniform, including two voltage amplitudes e and f. When the signal's DC strength is large, it will exceed the upper limit of the low-pass amplifier circuit when it is amplified by the low-pass amplifier circuit.
  • a capacitor CA is set before the voltage signal is output to the low-pass amplifier circuit, and DC is filtered by the capacitor CA , Only the AC part is reserved; in order to obtain a voltage signal of sufficient strength after the low-pass amplifier circuit, a DC output power supply VREF is connected between the capacitor CA and the low-pass amplifier circuit to provide a uniform DC for the voltage signal after filtering the DC. Obtain the voltage amplitude c.
  • the capacitor CA filters out non-uniform intensity direct current, and then provides a uniform intensity direct current through the power supply VREF, which is convenient to provide a better signal source for the low-pass amplifier circuit and ensure the signal quality after low-pass amplification.
  • the second low-pass filter circuit can be implemented with a simple RC circuit, can also be implemented with an operational amplifier, or can be used in combination with an RC circuit and an operational amplifier.
  • the main function of the second low-pass filter circuit is to filter out the frequency part to obtain the decision threshold electrical signal.
  • the second low-pass filter circuit can also be added with a functional circuit for filtering high-frequency signals.
  • the functional circuit is usually an RC circuit.
  • RC circuit is a commonly used filter circuit. Different RC parameters can achieve different filtering functions. For example, one type of RC circuit can achieve high frequency filtering, and another type of RC circuit can achieve low frequency filtering; The parameters are not clearly limited, and are only described from the perspective of implementing functions. Specific parameters can be set by those skilled in the art as required.
  • the above-mentioned functional circuit for filtering high-frequency signals is provided in the second low-pass filter circuit; in an embodiment of the present application, the above-mentioned filter is not provided in the second low-pass filter circuit.
  • the high-frequency signal functional circuit this is because the circuit before the second low-pass filter circuit cannot handle high-frequency signals well.
  • the high-frequency signal processing ability of the subtraction amplifier circuit is very poor, which makes the second low-pass filter circuit
  • the previous circuit already has a certain high frequency filtering function.
  • an RC circuit for filtering the high frequency part can be added to the second low pass filter circuit.
  • the RC circuit that filters out the high frequency part can also be arranged before the subtractive amplifier circuit.
  • FIG. 12 is a schematic structural diagram of a second low-pass filter circuit provided by an embodiment of this application.
  • the second low-pass filter circuit shown in FIG. 12 includes an RC circuit for filtering high frequencies and an operational amplifier 801.
  • the operational amplifier is used to generate the decision threshold electrical signal.
  • the high frequency part is filtered out by the RC circuit to retain the low frequency part, and then the low frequency signal is divided into two paths, namely the first low frequency electrical signal and the second low frequency electrical signal.
  • the first low frequency electrical signal is used to form the decision threshold electrical signal to
  • the second low-frequency electrical signal enters a decision, thereby generating a digital signal usable by the microprocessor.
  • the second low-pass filter circuit includes a peripheral resistor R9 and a peripheral capacitor C5 to form an RC filter circuit that filters out high frequencies.
  • One end of the resistor R9 is connected to the signal, and the other end is connected to one end of the capacitor C5.
  • the capacitor C5 The other end of is grounded, and one end of the capacitor C5 outputs the filtered signal.
  • the signal output from one end of the capacitor C5 is divided into two paths, namely the first low-frequency electrical signal and the second low-frequency electrical signal.
  • the first low-frequency electrical signal enters the operational amplifier, and the second low-frequency electrical signal enters the comparison circuit.
  • the second low-pass filter circuit does not have a circuit for filtering out the high-frequency part, so the output signal can also be divided into two paths after the subtraction amplifier circuit.
  • the filter circuit/filter is generally composed of reactive components, such as a capacitor C in parallel with the load resistance, or an inductor L in series with the load, and various multiple filter circuits composed of capacitors and inductors.
  • Commonly used filter circuits include passive filter and active filter. If the filter circuit components are only composed of passive components (resistors, capacitors, inductors), it is called a passive filter circuit.
  • the main forms of passive filtering are capacitive filtering, inductive filtering and compound filtering (including inverted L-type, LC filtering, LC ⁇ -type filtering and RC ⁇ -type filtering, etc.). If the filter circuit is composed of not only passive components, but also active components (bipolar tubes, unipolar tubes, integrated operational amplifiers), it is called an active filter circuit.
  • the main form of active filter is active RC filter, also known as electronic filter.
  • FIG. 13 is a schematic diagram of voltage signal conversion realized by the circuit in FIG. 12.
  • the second low-pass filter circuit receives the voltage signal output from the subtractive amplifier circuit and outputs the decision threshold electrical signal for subsequent digital signal generation.
  • the decision threshold electrical signal may specifically be a DC signal.
  • the decision threshold electrical signal is input to the second input terminal of the comparison circuit.
  • the signal voltage range obtained after the subtraction amplifier circuit in Figure 11 is at least below 0V.
  • the signal can be provided A DC voltage is used to increase the voltage of the signal as a whole.
  • the DC voltage is generally realized by connecting the power supply in the circuit; of course, if the comparison voltage range of the comparator is set below 0V, it can be adapted to the voltage range of the signal , Can also provide DC voltage without power supply.
  • the signal voltage shown in FIG. 13 has undergone a DC voltage boost process, and the overall signal voltage range has been increased to more than 0V.
  • FIG. 14 is a schematic structural diagram of a comparison circuit provided by an embodiment of the application.
  • the comparison circuit includes a comparator 901. As shown in FIG. 14, the first input terminal of the comparator 901 receives the second low-frequency electrical signal, the second input terminal receives the decision threshold electrical signal from the second low-pass filter circuit, and the comparison current compares the signal at the first input terminal with the first input terminal. The signals at the two input terminals are compared, and the output terminal outputs a third low-frequency electrical signal.
  • the comparator may also include power supply pins V+, V- and an enable pin SD; the power supply pin is used for power supply, and the enable pin is a switch pin.
  • the comparator can also be replaced by an operational amplifier.
  • the comparator in the comparison circuit is set as a comparator with adjustable hysteresis ratio.
  • the hysteresis comparator is also called Schmitt trigger, hysteresis comparator.
  • the purpose of using the hysteresis comparator in this application is to remove the noise in the signal.
  • the fifth resistor R5, the sixth resistor R6 and the comparator 901 form a hysteresis comparator.
  • One end of the fifth resistor R5 receives the decision threshold electrical signal from the second low-pass filter circuit, and the other end is connected to The first input terminal of the comparator and one end of the sixth resistor R6 are connected, and the other end of the sixth resistor R6 is connected to the output terminal of the comparator; in some embodiments of the present application, the seventh resistor R7 and the eighth resistor R8 is connected in parallel to both ends of the sixth resistor R6, and the switch 902 controls the conduction of the seventh resistor R7, the eighth resistor R8 and the sixth resistor, so that the sixth resistor, the seventh resistor R7, and the eighth resistor R8 form a resistance unit
  • the resistance value is adjustable.
  • the function of the original single sixth resistor R6 in the circuit is replaced by the resistance unit, which realizes the adjustable hysteresis ratio of the comparator, so that the fifth resistor R5 and the sixth resistor R6 and the comparator 901 An adjustable hysteresis comparator is formed.
  • the hysteresis comparator introduces a threshold voltage, which is related to the ratio of R5 and R6.
  • the R6 resistor is connected in parallel with R7 or more resistors through the switch 902, and then the proportional relationship between the resistance at R6 and the R5 resistor is adjusted to adjust the threshold voltage.
  • the switch 902 can be a single switch connected to the respective branches of the seventh resistor and the eighth resistor respectively; it can also be a switch unit connected to the seventh resistor and the eighth resistor respectively; through the switch 902 Realize the conduction control of other resistors connected in parallel with the sixth resistor and the sixth resistor.
  • a smaller resistance value can be used at R6 to increase the threshold and filter out the noise.
  • a larger resistor can be used at R6 to reduce the threshold so that the signal can be output and the noise can be filtered out.
  • FIG. 15 is a schematic diagram of voltage signal conversion of the comparison circuit in FIG. 14. As shown in Figure 15, the threshold electrical signal judges the low-frequency signal to generate
  • the low-frequency signal receiving pin of the microprocessor is used to receive the low-frequency signal in the dual-frequency signal.
  • the microprocessor is connected to the output terminal of the comparison circuit.
  • the third low-frequency electrical signal can be a digital signal. signal.
  • the received optical power intensity detection pin of the microprocessor is used to receive the photovoltage generated by the photocurrent to generate the received optical power intensity signal.
  • the received optical power intensity is one of the working indicators of the optical module required to be monitored in the industry standard.
  • the optical module needs to be collected and stored by itself, and read from the optical module when needed by the host computer.
  • the received light power intensity is derived from the light current intensity generated by the light receiving chip, which is collected, calculated and stored by the microprocessor MCU of the optical module.

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Abstract

本申请提供一种光模块，涉及光纤通信技术领域。本申请实施例提供的光模块，光接收芯片，一端通过分压电阻电连接至升压电路，另一端与跨阻放大芯片电连接，接收高低频混合的光信号；减法放大电路，从分压电阻的两端分别接收电压信号，输出端与第二低通滤波电路的输入端电连接；第二低通滤波电路的输入端还与比较电路的第一输入端电连接，输出端与比较电路的第二输入端电连接，输出判决门限电信号；比较电路的输出端与微处理器电连接，输出低频数字电信号；跨阻放大芯片与限幅放大芯片电连接，限幅放大芯片输出高频电信号。

Description

光模块
本申请要求在2019年06月26日提交中国专利局、申请号为201910562559.6、发明名称为“一种光模块”的中国专利申请的优先权，其全部内容通过引用结合在本申请中。
技术领域
本申请涉及光通信技术领域，尤其涉及一种光模块。
背景技术
随着光纤通信技术的发展，在一些光纤通信领域中，要求在原本的高速业务通道上加载低频信号。例如，国际标准化组织FSAN提出在点对点密集波分复用无源光网络中增加辅助管理与控制信道(Auxiliary Management and Control Channel，简称AMCC)，AMCC的传输速率一般在在100Kbit/s以下，即属于低频信号。因此，这就要求PTP WDM PON网络既能承载原有的高速业务信号，也能承载AMCC这样的低频信号。
PTP WDM PON网络中光信号的接收和发送都由光模块完成，但是，已有技术中，光模块仅能接收和发送高频的数字业务信号，而无法接收和发送低频信号。
因此，已有技术中的光模块无法接收同时承载高频信号和低频信号的混合信号。
发明内容
一方面，本申请实施例提供一种光模块，包括光接收芯片、跨阻放大芯片、限幅放大芯片、第一低通滤波电路、第二低通滤波电路、比较电路及微处理器； 跨阻放大芯片分别与光接收芯片、限幅放大芯片及第一低通滤波电路电连接；光接收芯片向跨阻放大芯片输出第一混合频率电信号；跨阻放大芯片向限幅放大芯片输出第二混合频率电信号；限幅放大芯片输出高频电信号；跨阻放大芯片向第一低通滤波电路输出第三混合频率电信号；第三混合频率电信号为第一混合频率电信号的镜像信号；第二低通滤波电路与第一低通滤波电路电相连，第一低通滤波电路向第二低通滤波电路输出第一低频电信号；比较电路的第一输入端与第一低通滤波电路电相连，比较电路的第二输入端与第二低通滤波电路电相连，比较电路的输出端与微处理器相连，第一低通滤波电路向比较电路输入第二低频电信号；第二低通滤波电路向比较电路输入判决门限电信号；比较电路向微处理器输出第三低频电信号。
另一方面，本申请实施例提供一种光模块，包括光接收芯片、升压镜像电路、跨阻放大芯片、限幅放大芯片、第一低通滤波电路、第二低通滤波电路、比较电路及微处理器；跨阻放大芯片分别与光接收芯片及限幅放大芯片电连接；光接收芯片向跨阻放大芯片输出第一混合频率电信号；跨阻放大芯片向限幅放大芯片输出第二混合频率电信号，限幅放大芯片输出高频电信号；升压镜像电路分别与光接收芯片及第一低通滤波电路电连接；升压镜像电路向光接收芯片输出工作高压；升压镜像电路向第一低通滤波电路输出第一混合频率电信号的镜像电信号；第二低通滤波电路与第一低通滤波电路电相连，第一低通滤波电路向第二低通滤波电路输出第一低频电信号；比较电路的第一输入端与第一低通滤波电路电相连，比较电路的第二输入端与第二低通滤波电路电相连，比较电路的输出端与微处理器相连；第一低通滤波电路向比较电路输入第二低频电信号；第二低通滤波电路向比较电路输入判决门限电信号；比较电路向微处理器输出第三低频 电信号。
第三方面，本申请实施例提供一种光模块，包括光接收芯片，一端通过分压电阻电连接至升压电路，另一端与跨阻放大芯片电连接，接收高低频混合的光信号；
减法放大电路，从分压电阻的两端分别接收电压信号，输出端与第二低通滤波电路的输入端电连接；第二低通滤波电路的输入端还与比较电路的第一输入端电连接，输出端与比较电路的第二输入端电连接，输出判决门限电信号；
比较电路的输出端与微处理器电连接，输出低频数字电信号；跨阻放大芯片与限幅放大芯片电连接，限幅放大芯片输出高频电信号。
附图说明
为了更清楚地说明本申请的技术方案，下面将对实施例中所需要使用的附图作简单地介绍，显而易见地，对于本领域普通技术人员而言，在不付出创造性劳动性的前提下，还可以根据这些附图获得其他的附图。
图1为光通信终端连接关系示意图；
图2为光网络单元结构示意图；
图3为本申请实施例提供的一种光模块结构示意图；
图4为本申请实施例提供的一种光模块结构爆炸示意图；
图5为本申请实施例提供的一种光模块接收端(局部)分解结构示意图；
图6为图5中A区域局部放大图；
图7为图5中B区域局部放大图；
图8为本申请实施例提供的光模块另一结构示意图；
图9为图8所示光模块的电路连接示意图；
图10(A)为本申请实施例提供的一种减法放大电路相关电路结构示意图；
图10(B)为本申请实施例提供的一种低通放大电路相关结构示意图；
图11(A)为图10(A)中电路实现的电压信号转换示意图；
图11(B)为图10(B)中电路实现的电压信号转换示意图；
图12为本申请实施例提供的一种第二低通滤波电路结构示意图；
图13为图12中电路实现的电压信号转换示意图；
图14为本申请实施例提供的比较电路结构示意图；
图15为图14中比较电路的电压信号转换示意图。
具体实施方式
下面将结合本申请实施例中的附图，对本申请实施例中的技术方案进行清楚、完整地描述，显然，所描述的实施例仅仅是本申请一部分实施例，而不是全部的实施例。基于本申请中的实施例，本领域普通技术人员在没有做出创造性劳动前提下所获得的所有其他实施例，都属于本申请保护的范围。
光通信实现了将信号采用电和光两种不同的载体进行传输。光纤通信使用携带信息的光信号在光波导中传输，利用光在光纤等光波导中的无源传输特性可以实现低成本、低损耗的信息传输；而计算机等信息处理设备采用的是电信号，这就需要在光纤通信系统中实现电信号与光信号的相互转换。
图1为光通信终端连接关系示意图。如图1所示，光通信终端的连接主要包括光网络单元100、光模块200、光纤101及网线103；
光纤的一端连接远端服务器，网线的一端连接本地信息处理设备，本地信息处理设备与远端服务器的连接由光纤与网线的连接完成；而光纤与网线之间的 连接由具有光模块的光网络单元完成。
光模块200的光口与光纤101连接，与光纤建立双向的光信号连接；光模块200的电口接入光网络单元100中，与光网络单元建立双向的电信号连接；光模块实现光信号与电信号的相互转换，从而实现在光纤与光网络单元之间建立连接；具体地，来自光纤的光信号由光模块转换为电信号后输入至光网络单元100中，来自光网络单元100的电信号由光模块转换为光信号输入至光纤中。光模块200是实现光电信号相互转换的工具，不具有处理数据的功能，在上述光电转换过程中，信息并未发生变化。
光网络单元具有光模块接口102，用于接入光模块，与光模块建立双向的电信号连接；光网络单元具有网线接口104，用于接入网线，与网线建立双向的电信号连接；光模块与网线之间通过光网络单元建立连接，具体地，光网络单元将来自光模块的信号传递给网线，将来自网线的信号传递给光模块，光网络单元作为光模块的上位机监控光模块的工作。
至此，远端服务器通过光纤、光模块、光网络单元及网线，与本地信息处理设备之间建立双向的信号传递通道。
常见的信息处理设备包括路由器、交换机、电子计算机等；光网络单元是光模块的上位机，向光模块提供数据信号，并接收来自光模块的数据信号，常见的光模块上位机还有光纤路终端等。
图2为光网络单元结构示意图。如图2所示，在光网络单元100中具有电路板105，在电路板105的表面设置笼子106；在笼子106中设置有电连接器接口，用于接入金手指等光模块电口；在笼子106上设置有散热器107，散热器107具有增大散热面积的翅片等凸起结构。
光模块200插入光网络单元中，具体为光模块的电口插入笼子106中的电连接器，光模块的光口与光纤101连接。
笼子106位于电路板上，将电路板上的电连接器包裹在笼子中；光模块插入笼子中，由笼子固定光模块，光模块产生的热量通过光模块壳体传导给笼子，最终通过笼子上的散热器107进行扩散。
图3为本申请实施例提供的一种光模块结构示意图，图4为本申请实施例提供的一种光模块结构爆炸示意图，如图3、图4所示，本申请实施例提供的光模块200包括上壳体201、下壳体202、解锁手柄203、电路板300、光发射次模块301、光接收次模块400。
上壳体201与下壳体202形成具有两个开口的包裹腔体，两个开口具体可以是位于光模块同一端的两处开口(204、205)，也可以是在光模块不同端的的两处开口；其中一个开口为电口204，用于插入光网络单元等上位机中，另一个开口为光口205，用于外部光纤接入以连接内部光纤，电路板300、光发射次模块301及光接收次模块400等光电器件位于包裹腔体中。
上壳体及下壳体一般采用金属材料，利于实现电磁屏蔽以及散热；采用上壳体、下壳体结合的装配方式，便于将电路板等器件安装到壳体中，一般不会将光模块的壳体做成一体结构，这样在装配电路板等器件时，定位部件、散热以及电磁屏蔽结构无法安装，也不利于生产自动化。
解锁手柄203位于腔体/下壳体202的外壁，拉动解锁手柄的末端可以在使解锁手柄在外壁表面相对移动；光模块插入上位机时由解锁手柄将光模块固定在上位机的笼子里，通过拉动解锁手柄以解除光模块与上位机的卡合关系，从而可以将光模块从上位机的笼子里抽出。
电路板位于由上、壳体形成包裹腔体中，电路板上设置有芯片、电容、电阻等电器件。根据产品的需求选择需要设置的芯片，常见的芯片包括微处理器MCU、时钟数据恢复芯片CDR、激光驱动芯片、跨阻放大TIA芯片、限幅放大LA芯片、电源管理芯片等。
跨阻放大芯片与光接收芯片紧密关联，近距离短走线设计可以保证良好的接收信号质量，光模块的一种封装形态中，将跨阻放大芯片与光接收芯片一起封装在独立封装体中，如封装在同一同轴管壳TO中或同一方形腔体中；独立封装体独立于电路板，光接收芯片及跨足放大芯片通过独立封装体与电路板形成电连接；光模块的另一种封装形态中，可以不采用独立封装体，而是将光接收芯片与跨阻放大芯片设置在电路板表面。当然，也可以将光接收芯片独立封装，而将跨阻放大芯片设置在电路板上，接收信号质量也能满足某些相对较低的要求。
电路板上的芯片可以是多合一芯片，比如将激光驱动芯片与MCU芯片融合为一个芯片，也可以将激光驱动芯片、限幅放大芯片及MCU融合为一个芯片，芯片是电路的集成，但各个电路的功能并没有因为集合而消失，只是电路形态发生整合。所以，当电路板上设置有MCU、激光驱动芯片及限幅放大芯片三个独立芯片，这与电路上设置一个三功能合一的单个芯片，方案是等同的。
电路板端部表面具有金手指，金手指由相互独立的一根根引脚组成的，电路板插入笼子中的电连接器中，由金手指与上位机建立电连接。
电路板是光模块主要电器件的载体，没有设置在电路板上的电器件最终也与电路板电连接，电路板上的电连接器实现光模块与其上位机的电连接。光模块通常采用的电连接器为金手指。
光模块还包括光发射次模块及光接收次模块，光发射次模块及光接收次模 块可以统称为光学次模块。图4为本申请实施例提供的光模块结构分解图，如图4所示，本申请实施例提供的光模块包括光发射次模块301及光接收次模块400，光发射次模块与光接收次模块在电路板表面错开设置，利于实现更佳的电磁屏蔽效果。
光发射次模块301设置在电路板300表面，在另一种常见的封装方式(如同轴TO封装)中，光发射次模块独立封装，与电路板物理分离，通过柔性板实现电连接；光接收次模块400设置在电路板300表面，在另一种常见的封装方式(如同轴TO封装)中，光接收次模块独立封装，与电路板物理分离，通过柔性板实现电连接。
目前业内提出一种混合频率光信号通信需求，在一路高频率信号的基础上叠加一路低频率信号，两路不同频率的信号通过同一波长的光传输；例如在10Gbps或25Gbps等高频信号基础上，同时增加一个低频50Kbps的信号；10Gbps或25Gbps等高频信号为正常的业务信号，在不占用正常业务的同时，增加另一路50Kbps的低频信号执行其它功能。对于光模块的发射端，需要发出双频率的光信号；对于光模块的接收端，需要接收双频率的光信号，然后将光信号中不同频率的信号分别解调，从而分别得到高频信号及低频信号。
为了实现对低频信号的接收，本申请实施例提供了如下技术构思：低频接收电路采用光接收芯片的响应电流解调出低频信号。光接收芯片接收到光后，会感应出响应电流，此响应电流为模拟电流信号；将该电流信号转化为电压信号，然后依次通过低通滤波、运放放大后再分成两路，其中一路经过低通滤波器取其直流分量，然后与另一路经过比较器进行比较后，即可解调出MCU可快速处理的数字信号。MCU在处理数字信号时，可快速识别出1或0，加快处理速度。
光模块的接收端包括光接收芯片、跨阻放大芯片TIA、限幅放大芯片LA、低通滤波单元、比较电路及微处理器。芯片的本质是电路的集成，电路可以集成到芯片中，芯片中的部分功能也可以由电路板上的电路实现。实现芯片的功能，可以由芯片实现，也可以由电路实现，也可以由主芯片结合外围电路实现。不同功能也可以由同一芯片集成，电路集成形态的变化仍属于本申请的保护范围。
本申请提供的一个实施例中，光模块中的光接收芯片、限幅放大芯片、低通滤波单元(低通滤波单元包括第一低通滤波电路及第二低通滤波电路)、比较电路及微处理器设置在电路板的表面，由于电路板的面积有限，上述电路及微处理器根据布局需要设置在电路板同侧表面，可以分布在电路板的不同侧表面上。采用电路处理电信号，由于来自光接收芯片的电信号或来自镜像电路的电信号一般较小，通常会在电路中增加放大电路以提高信号强度，本申请实施例将放大功能与第一低通滤波电路融合，采用低通放大电路，后续以低通放大电路为例说明。
本申请提供的另一个实施例中，光模块中的光接收芯片、限幅放大芯片、减法放大电路、低通滤波单元(低通滤波单元包括第二低通滤波电路)、比较电路及微处理器设置在电路板的表面，由于电路板的面积有限，上述电路及微处理器根据布局需要设置在电路板同侧表面，可以分布在电路板的不同侧表面上。采用电路处理电信号，由于来自光接收芯片的电信号或来自镜像电路的电信号一般较小，通常会在电路中增加放大电路以提高信号强度，本申请实施例采用减法放大电路中的放大功能提高信号强度，同时减法放大电路还是去除噪声信号。
具体地，依据光模块的封装形态不同，光模块的光接收芯片可以独立设置在同轴封装中，限幅放大芯片优选与光接收芯片封装在同轴封装中，低通放大电路或减法放大电路、第二低通滤波电路、比较电路及微处理器设置在电路板的表面， 同轴封装与电路板电连接，具体的电连接方式可以是柔性电路板。
芯片的本质是电路的集成，电路的具体形态变化不影响本申请实施例的保护范围，本申请实施例以一种具体的产品方案举例说明。
图5为本申请实施例提供的一种光模块接收端(局部)分解结构示意图。如图5所示，本申请实施例提供的光模块中包括电路板300及光接收端400。光接收端400设置在电路板300表面，光接收端400包括光接收芯片401、光波导402、盖板403、跨阻放大芯片500及限幅放大芯片600，电路板300表面具有金手指303。
光接收芯片、跨阻放大芯片及限幅放大芯片分别设置在电路板表面，与电路板实现电连接；盖板403将光接收芯片、跨阻放大芯片、限幅放大芯片及光波导盖合在电路板表面。
图6为图5中A区域局部放大图，A区域包括光波导402、光接收芯片401及跨阻放大芯片TIA 500。如图6所示，光接收芯片401设置在电路板300表面，光波导402位于光接收芯片401的上方，光接收芯片401的光敏面朝向光波导402，承载混合频率信号的光通过光波导402传输至光接收芯片401中，具体地，光波导402的端面为斜面，光在光波导402的斜面处发生反射，进而射入光接收芯片的光敏面上。
光接收芯片是光模块接收端用于接收光信号的芯片，携带双频率混合信号的光射入光接收芯片的光敏面后，光接收芯片利用光电转换效应生成电流信号，由电流承载混合频率信号，在光转换为电流的过程中，信号的载体发生改变，但信息没有变化。光接收芯片输出的信号通常是模拟信号，常见的光接收芯片为PIN光电二极管或光电雪崩二极管APD。
光接收芯片产生的第一混合频率电信号(具体是光电流)传输至跨阻放大芯片中，光接收芯片产生的光电流包括高频、低频两部分信号，为了分别接收高频、低频信号，需要将光电流分为至少两部分。一般采用镜像电路对光电流进行镜像，视后续信号处理的需求，镜像后产生的电流可以是一路，也可以是两路或多路。
具体地，当光接收芯片采用PIN光电二极管方案时，与PIN光电二极管匹配的跨阻放大芯片具有电流输出端501及光电压输出端(502、503)，电流输出端501输出与光接收芯片相同的电流，用于后续低频信号接收；光电压输出端(502、503)输出由光电流转换的光电压；
具体地，限幅放大芯片中具有第一镜像电路，将来自光接收芯片的光电流进行镜像，将镜像得到的电流通过电流输出端输出，实现了输出第三混合频率电信号，用于后续的低频信号接收；来自光接收芯片的光电流用于后续高频信号接收。来自光接收芯片的光电流是最原始的电流，优先用于高频信号的解调，以保证业务数据质量，当然，理论上而言，由于镜像后的电流与光电流相同，也可以将镜像得到的电流用于高频信号接收，而将光电流用于低频信号接收。跨阻放大芯片也可以集成转换电路，以将用于低频信号接收的电流转换为电压信号；
具体地，光模块中的第一镜像电路可以镜像出两路镜像电流，一路用于低频或高频信号的解调，另一路用于实现接收光功率强度检测功能。接收光功率强度RSSI检测电路一般由接地电阻及微处理器组成，另一路镜像电流经接地电阻转换为电压信号后输入微处理器中，由微处理器采样获得接收光功率强度信号；
具体地，第一镜像电路可以设置在跨阻放大芯片TIA中，也可以设置在跨阻放大芯片之外在电路板上。镜像电流可以直接由镜像电路输出；也可以接入跨阻放大芯片中，由跨阻放大芯片的电流输出端输出；
光电流信号进入跨阻放大芯片后被放大并转换为电压信号，电压信号从跨阻放大芯片输出，实现了输出第二混合频率电信号，第二混合频率电信号优选以差分电压信号形态输出，需要两个输出端口(502、503)；
具体地，当光接收芯片采用APD光电雪崩二极管方案时，与APD光电雪崩二极管匹配的跨阻放大芯片具有光电压输出端(502、503)，光电压输出端(502、503)输出由光电流转换的光电压，优选以差分形态输出。
具体地，由于APD光电雪崩二极管工作时需要高于光模块正常工作的电压，所以光模块中增加升压电路，升压电路用于为APD提供工作高压；为了便于接收光电流，光模块中增加第二镜像电路，升压电路通过镜像电路中的一条通路与APD相连，该通路中的电流即APD产生的光电流，该通路中的电流用于后续进行高频信号接收；第二镜像电路将该通路中的电流进行镜像，从而获得光电流的镜像电流，第三混合频率电信号具体表现为该镜像电流；该镜像电流用于后续进行低频信号的接收。来自光接收芯片的光电流是最原始的电流，优先用于高频信号的解调，以保证业务数据质量，当然，理论上而言，由于镜像后的电流与原电流相同，也可以将镜像得到的电流用于高频信号接收，而将原电流用于低频信号接收。第二镜像电路中也可以集成转换电路，以将用于低频信号接收的电流转换为电压信号；
具体地，光模块中的的第二镜像电路可以镜像出两路镜像电流，一路用于低频或高频信号的解调，另一路用于实现接收光功率强度检测功能。接收光功率强度RSSI检测电路一般由接地电阻及微处理器组成，另一路镜像电流经接地电阻转换为电压信号后输入微处理器中，由微处理器采样获得接收光功率强度信号；
具体地，升压电路可以设置在跨阻放大芯片中，也可以设置在电路板上，其 呈现形态可以是芯片，也可以是电路，也可以是主芯片结合外围电路；
具体地，第二镜像电路可以设置在跨阻放大芯片中，也可以设置在电路板上，其呈现形态可以是芯片，也可以是电路，也可以是主芯片结合外围电路。
光电流信号进入跨阻放大芯片后被放大并转换为电压信号，电压信号从跨阻放大芯片输出，实现了输出第二混合频率电信号，电压信号优选以差分形态输出。
除了镜像电路之外，在使用APD进行光信号接收时，还可以在升压电路与APD连接的电路上直接获得与光电流相关的信号，以用于低频信号的接收。
图7为图5中B区域局部放大图。如图7所示，本申请实施例提供的光模块中，限幅放大芯片600设置在电路板300上，限幅放大芯片TIA与跨阻放大芯片LA相连，用于接收光电压信号。限幅放大芯片将光电压信号进一步放大并限制在设定的输出差分幅度中，从限幅放大芯片输出的电压信号即为高频信号。限幅放大芯片具有输入端口(601、602)以接收来自跨阻放大芯片的光电压信号(差分形态的光电压信号)，限幅放大芯片具有输出端口(603、604)以输出高频信号。电路板300上的金手指具有引脚605、606，高频信号通过引脚605、606输出至上位机。在传输高频信号的引脚606、606两侧，具有接地引脚607、608，接地引脚用于实现对传输高频信号引脚的电隔离。
限幅放大芯片与跨阻放大芯片之间连接有电容。具体地，跨阻放大芯片输出两路差分信号，第一电容将差分信号的一路接入限幅放大芯片的第一输入端，第二电容将差分信号的另一路接入限幅放大芯片的第二输入端；限幅放大芯片结合第一电容以及第二电容，对跨阻放大芯片所输出的电压信号进行高通滤波，以输出高频信号。
此外，实际应用中，限幅放大芯片的设计一般针对高频电信号，因为光纤通信业务是高速率、超高速率的信号传输，而限幅放大芯片无法对频率差距如此大的混合频率信号同时接收，限幅放大芯片一般只会识别电信号中的高频部分。
具体地，第一电容、第二电容以及限幅放大芯片内部集成的上拉电阻构成一个高通滤波器，当电压信号经过第一电容、第二电容以及限幅放大芯片时，其中的低频信号被滤掉，从而实现高通滤波。
图8为本申请实施例提供的光模块另一结构示意图，图9为图8所示光模块的电路连接示意图。图5展示了电路板的一侧表面，图8展示了电路板的另一侧表面，由于电路板表面的空间有限，电路板上的芯片分别设置在电路板上下两个表面。图8示出了部分电路/芯片在光模块电路板上的位置，具体包括减法放大电路700、第二低通滤波电路800、比较电路900及微处理器MCU304。图9中示出了图8中相关电路/芯片之间的电连接。如图8所示，减法放大电路700、第二低通滤波电路800、比较电路900及微处理器304设置在电路板的表面，减法放大电路700分别与第二低通滤波电路800及比较电路900相连，第二低通滤波电路与比较电路900相连，比较电路与微处理器MCU304相连。
如图9所示，以雪崩光电二极管APD接收光信号为示例，光电雪崩二极管APD的一端通过分压电阻R连接至升压电路Vapd，另一端连接至跨阻放大芯片TIA中。由于分压电阻R与TIA串联在APD两端，所以流过分压电阻R的电流与流入TIA中的电流一致，采集分压电阻两端的电压信号即可得到光电流对应的光电压信号，进而可以用于低频信号的接收；流入TIA的电流信号用于高频信号的接收。
用于进行低频信号接收的电流或电压接入减法放大电路中。减法放大电路以运算放大主芯片结合外围电路为例，低频信号以电压信号为例。
图10(A)为本申请实施例提供的一种减法放大电路相关电路结构示意图。减法放大电路700包括第一电阻R1、第二电阻R2、第三电阻R3、第四电阻R4及运算放大器701。连接在升压电路Vapd与光电雪崩二极管之间的分压电阻R具有M1与M2两端，第一电阻R1一端与M1连接，另一端与运算放大器的第一输入端连接；第三电阻R3一端与M2连接，另一端与运算放大器的第二输入端连接。在第一电阻与运算放大器第一输入端之间连接有接地的第二电阻R2，在第三电阻与运算放大器第二输入端之间连接有第四电阻的一端，第四电阻的另一端与运算放大器的输出端连接。上述减法放大电路是一种教科书中常用的减法放大电路，其中第一电阻R1与第三电阻R3可以具有相同的阻值，第二电阻R2与第四电阻R4也可以具有相同的阻值。当然，在上述减法放大电路的基础上，可以改进出多种其他类型的电路，教科书中提供的减法放大电路也还有其他类型。
由于分压电阻的分压作用，M1处与M2处的电压不同，但信号相同，即M1处与M2处具有相同的信号，但信号的幅度不同。信号中除了具有需要接收的高低频的信号之外，还有噪声信号，减法放大电路的主要作用之一就是去除噪声。噪声幅度来源于电路中的引入噪声，M1和M2处的噪声幅度相当。M1处的高低频信号幅度明显大于M2处的高低频信号幅度，但两处的高低频信号相同，所以M1处的高低频信号减去M2处的高低频信号，相减之后得到与M1处相同的高低频信号，但高低频信号幅度相对降低，使用运算放大器将高低频信号的幅度提升以得到放大的高低频信号。
而M1处的噪声信号幅度与M2处的噪声信号幅度略相当，但两处的噪声信号相同，所以M1处的噪声信号减去M2处的噪声信号，相减之后得到与M1处相同的噪声信号，但噪声信号幅度明显降低，实现了去噪声效果。
通过对高低频信号减法并放大、对噪声信号减法，实现了去除噪声信号、得到较大的高低频信号，提升了信号的信噪比。
考虑到运算放大器的实际电压工作性能，以及分压电阻两端具有升压电路输入的较大电压，M1处与第一电阻之间、M2处与第三电阻之间分别接入电容，通过电容的通交流阻直流特性，将升压电路输出的直流高压阻挡，而交流形态的信号顺利通过电容以接入减法放大电路中。使用电容隔离直流之后，交流信号的电压范围往往会到达0V以下。
M1和M2两处的信号经过减法放大器后，低频信号经过放大后增大了信号幅度，噪声减法后信号变小，即使经过放大器，也会增大与低频有效信号的差值，信噪比有效提升。
图11(A)为图10(A)中电路实现的电压信号转换示意图。如图11(A)所示，在M1处与M2处具有相同的高低频信号data及噪声信号noise，但M1处的高低频信号幅度大于M2处的高低频信号幅度，M1处的噪声信号与M2处的噪声信号相当；经过减法放大电路之后，噪声信号相减进而消除，高低频信号相减后信号幅度变小，经过放大后幅度变大，最终得到了信噪比提升的高低频信号。
在信号进入减法放大电路之前，可以对其进行高频滤除，保留低频信号及噪声信号，所以上述对于高低频信号的处理也可以是针对低频信号的处理。
在一种具体的实施方式中，减法放大电路700这一部分可以使用低通放大电路替换。对低频信号的接收采用镜像电路提供的镜像电流为例，用于进行低频 信号接收的电流接入接地电阻的一端，接地电阻的另一端接地，接地电阻一端还与低通放大电路连接，通过接地的电阻R2将电流转换为电压后输入低通放大电路中。
图10(B)为本申请实施例提供的一种低通放大电路相关结构示意图。如图10(B)所示，低通放大电路以主芯片结合外围电路为例，低频信号以电流信号为例。低通放大电路包括运算放大主芯片702、外围电阻RD、RE及外围电容CD，运算放大主芯片结合电阻RD、电阻RE形成滤波放大电路，具体地，电阻RD一端接地，另一端接入运算放大主芯片的输入引脚IN-；电阻RE一端接入运算放大主芯片的输入引脚IN-，另一端接入运算放大主芯片的输出引脚OUT；为了在上述滤波放大电路的基础上调节其截止频率的范围，增加电容CD，电容CD一端接入运算放大主芯片的输入引脚IN-，另一端接入运算放大主芯片的输出引脚OUT。运算放大主芯片还包括电源引脚V+、V-及使能引脚SD；电源引脚用于给运算放大主芯片供电，使能引脚是运算放大主芯片的开关引脚。
低通放大电路将接收到的电压信号放大并滤掉其高频信号部分，仅留下经过放大的低频信号部分。
图11(B)为图10(B)中电路实现的电压信号转换示意图。如图11(B)所示，接入低通放大电路的电压信号是模拟信号，包括直流部分a及交流部分b，其直流部分的强度不统一，包括e、f两种电压幅度，当电压信号的直流强度较大时，经低通放大电路放大时，会超出低通放大电路的上限，为了避免这种情况，在电压信号输出低通放大电路之前设置电容CA，通过电容CA滤除直流，仅保留交流部分；为了经低通放大电路后得到足够强度的电压信号，在电容CA与低通放大电路之间接入直流输出电源VREF，为滤除直流之后的电压信号提供一 个统一的直流，得到电压幅度c。经过电容CA滤除不统一强度的直流，然后通过电源VREF提供一个统一强度的直流，便于为低通放大电路提供较佳的信号源，保证低通放大后的信号质量。
第二低通滤波电路可以用一个简单的RC电路实现，也可以使用运算放大器实现，也可以将RC电路与运算放大器结合使用。第二低通滤波电路的主要作用是将频率部分滤除、得到判决门限电信号。
第二低通滤波电路在上述电路结构的基础上，还可以在前增加一个滤除高频信号的功能电路，该功能电路常见的为RC电路。RC电路是一种常用的滤波电路，不同的RC参数可以实现不同的滤波功能，比如一类RC电路可以实现高频滤除，另一类RC电路可以实现低频滤除；本申请对RC电路的参数不做明确的限定，仅从实现功能的角度进行描述，具体参数可以由本领域技术人员按需设置。
在本申请的某一实施例中，在第二低通滤波电路设置上述滤除高频信号的功能电路；在本申请的某一实施例中，在第二低通滤波电路中不设置上述滤除高频信号的功能电路，这是因为第二低通滤波电路之前的电路无法很好的处理高频信号，如减法放大电路的高频信号处理能力很差，这使得第二低通滤波电路之前的电路已经具备一定的高频滤除功能。当然为了更好的滤除高频部分，以实现对低频部分的接收，可以在第二低通滤波电路中增加实现滤除高频部分的RC电路。当然，也可以将滤除高频部分的RC电路设置在减法放大电路之前。
图12为本申请实施例提供的一种第二低通滤波电路结构示意图。图12中示出的第二低通滤波电路包括滤除高频的RC电路以及运算放大器801。运算放大器用于生成判决门限电信号。
经RC电路滤除高频部分以保留低频部分，然后将低频信号分为两路，即第一低频电信号及第二低频电信号，第一低频电信号用于形成判决门限电信号，以对第二低频电信号进入判决，从而生成微处理器可用的数字信号。
如图12所示，第二低通滤波电路包括外围电阻R9及外围电容C5，组成滤除高频的RC型滤波电路，电阻R9一端接入信号，另一端与电容C5的一端连接，电容C5的另一端接地，由电容C5的一端输出滤波之后的信号。通过调整电阻R9的阻值以及电容C5的容值，可以调节滤波电路的截止频率，控制滤波电路的滤波范围。
由电容C5一端输出的信号分为两路，即第一低频电信号及第二低频电信号，第一低频电信号这一路进入运算放大器中，第二低频电信号这另一路输入比较电路中。本申请某一实施例中第二低通滤波电路中不具有滤除高频部分的电路，所以也可以在减法放大电路之后，将输出的信号分为两路。
滤波电路/滤波器一般由电抗元件组成，如在负载电阻两端并联电容器C，或与负载串联电感器L，以及由电容，电感组成而成的各种复式滤波电路。常用的滤波电路有无源滤波和有源滤波两大类。若滤波电路元件仅由无源元件(电阻、电容、电感)组成，则称为无源滤波电路。无源滤波的主要形式有电容滤波、电感滤波和复式滤波(包括倒L型、LC滤波、LCπ型滤波和RCπ型滤波等)。若滤波电路不仅由无源元件，还由有源元件(双极型管、单极型管、集成运放)组成，则称为有源滤波电路。有源滤波的主要形式是有源RC滤波，也被称作电子滤波器。
图13为图12中电路实现的电压信号转换示意图。如图13所示，第二低通滤波电路接收来自减法放大电路输出的电压信号，输出判决门限电信号，用于后 续数字信号的生成，判决门限电信号具体可以是一个直流信号。该判决门限电信号输入比较电路的第二输入端。
实际设置比较器的比较电压范围时，一般在0V电压以上，而图11中经过减法放大电路之后得到的信号电压范围最低达到了0V以下，为了与比较器的比较电压范围匹配，可以向信号提供一个直流的电压，以整体提升信号的电压，提供直流电压一般采用在电路中接入电源的方式实现；当然，若将比较器的比较电压范围设置在0V以下，可以与信号的电压范围适配，也可以不使用电源提供直流电压。
图13中示出的信号电压经过了直流电压的升压处理，整体信号电压范围提升到了0V以上。
图14为本申请实施例提供的比较电路结构示意图。比较电路中包括比较器901。如图14所示，比较器901的第一输入端接收第二低频电信号，第二输入端接收来自第二低通滤波电路的判决门限电信号，比较电流将第一输入端的信号与第二输入端的信号进行比较，输出端输出第三低频电信号。比较器还可以包括电源引脚V+、V-及使能引脚SD；电源引脚用于供电，使能引脚是开关引脚。
比较器还可以使用运算放大器替代。
为了进一步消除噪声信号，比较电路中将比较器设置为可调滞回比例的比较器。滞回比较器又称施密特触发器，迟滞比较器，本申请使用滞回比较器的目的是去除掉信号中的噪声。图14中由第五电阻R5、第六电阻R6及比较器901组成了一种滞回比较器，第五电阻R5一端接收来自第二低通滤波电路的判决门限电信号，另一端分别与比较器的第一输入端、第六电阻R6的一端连接，第六电阻R6的另一端与比较器的输出端连接；在本申请的某些实施例中，将第七电 阻R7、第八电阻R8并联在第六电阻R6两端，由及开关902控制第七电阻R7、第八电阻R8与第六电阻的导通，使得第六电阻、第七电阻R7、第八电阻R8形成的电阻单元阻值可调，由该电阻单元替代原单一的第六电阻R6在电路中的作用，实现了比较器的滞回比例可调，进而使得由第五电阻R5及第六电阻R6及比较器901组成了可调的滞回比较器。
滞回比较器引入阈值电压，阈值电压与R5和R6的比值相关。本申请实施例中提供的可调滞回比较器，通过开关902，使R6电阻并联R7或更多电阻，进而调整R6处电阻的阻值与R5电阻的比例关系，调整阈值电压。
开关902可以是单独的一个个开关，分别连接在第七电阻、第八电阻等电阻各自的支路上；也可以是一个开关单元，分别接入第七电阻、第八电阻等电阻；通过开关902实现其他与第六电阻并联的电阻与第六电阻的导通控制。
当信号和噪声幅度大时，R6处可以用较小的电阻阻值，以提高阈值，滤除噪声。当信号和噪声幅度小时，R6处可以使用较大的电阻，以减小阈值，使得信号可以输出，噪声被滤掉。
图15为图14中比较电路的电压信号转换示意图。如图15所示，判决门限电信号对低频信号进行判决，从而生成
微处理器的低频信号接收引脚用于接收双频信号中的低频信号，微处理器与比较电路的输出端相连，为了提升微处理器的信号处理速度，该第三低频电信号可以是数字信号。
微处理器的接收光功率强度检测引脚用于接收由光电流产生的光电压，以生成接收光功率强度信号。接收光功率强度是行业标准中要求监控的光模块工作指标之一，需要光模块自行采集并存储，待上位机需要时从光模块中读取。接 收光功率强度源自光接收芯片产生的光电流强度，由光模块的微处理器MCU进行采集、运算及存储。
最后应说明的是：以上实施例仅用以说明本申请的技术方案，而非对其限制；尽管参照前述实施例对本申请进行了详细的说明，本领域的普通技术人员应当理解：其依然可以对前述各实施例所记载的技术方案进行修改，或者对其中部分技术特征进行等同替换；而这些修改或者替换，并不使相应技术方案的本质脱离本申请各实施例技术方案的精神和范围。

Claims (15)

  1. 一种光模块，其特征在于，包括光接收芯片、跨阻放大芯片、限幅放大芯片、第一低通滤波电路、第二低通滤波电路、比较电路及微处理器；
    所述跨阻放大芯片分别与所述光接收芯片、所述限幅放大芯片及所述第一低通滤波电路电连接；
    所述光接收芯片向所述跨阻放大芯片输出第一混合频率电信号；
    所述跨阻放大芯片向所述限幅放大芯片输出第二混合频率电信号；
    所述限幅放大芯片输出高频电信号；
    所述跨阻放大芯片向所述第一低通滤波电路输出第三混合频率电信号；所述第三混合频率电信号为所述第一混合频率电信号的镜像信号；
    所述第二低通滤波电路与所述第一低通滤波电路电相连，所述第一低通滤波电路向所述第二低通滤波电路输出第一低频电信号；
    所述比较电路的第一输入端与所述第一低通滤波电路电相连，所述比较电路的第二输入端与所述第二低通滤波电路电相连，所述比较电路的输出端与所述微处理器相连，
    所述第一低通滤波电路向所述比较电路输入第二低频电信号；
    所述第二低通滤波电路向所述比较电路输入判决门限电信号；
    所述比较电路向所述微处理器输出第三低频电信号。
  2. 如权利要求1所述的光模块，其特征在于，还包括电路板，所述光接收芯片、所述跨阻放大芯片、所述限幅放大芯片、所述第一低通滤波电路、所述第二低通滤波电路、所述比较电路及所述微处理器分别设置在所述电路板上。
  3. 如权利要求1所述的光模块，其特征在于，还包括电路板及独立封装体； 所述独立封装体与所述电路板电连接；
    所述限幅放大芯片、所述第一低通滤波电路、所述第二低通滤波电路、所述比较电路及所述微处理器分别设置在所述电路板上；
    所述光接收芯片、所述跨阻放大芯片分别设置在所述独立封装体中。
  4. 如权利要求1所述的光模块，其特征在于，所述限幅放大芯片与所述第一低通滤波电路之间接入电容及直流输出电源。
  5. 如权利要求1所述的光模块，其特征在于，所述第二滤波电路与所述比较电路之间接入隔离电路。
  6. 一种光模块，其特征在于，包括光接收芯片、升压镜像电路、跨阻放大芯片、限幅放大芯片、第一低通滤波电路、第二低通滤波电路、比较电路及微处理器；所述跨阻放大芯片分别与所述光接收芯片及所述限幅放大芯片电连接；
    所述光接收芯片向所述跨阻放大芯片输出第一混合频率电信号；
    所述跨阻放大芯片向所述限幅放大芯片输出第二混合频率电信号，所述限幅放大芯片输出高频电信号；
    所述升压镜像电路分别与所述光接收芯片及所述第一低通滤波电路电连接；所述升压镜像电路向所述光接收芯片输出工作高压；所述升压镜像电路向所述第一低通滤波电路输出所述第一混合频率电信号的镜像电信号；
    所述第二低通滤波电路与所述第一低通滤波电路电相连，所述第一低通滤波电路向所述第二低通滤波电路输出第一低频电信号；
    所述比较电路的第一输入端与所述第一低通滤波电路电相连，所述比较电路的第二输入端与所述第二低通滤波电路电相连，所述比较电路的输出端与所述微处理器相连；所述第一低通滤波电路向所述比较电路输入第二低频电信号；
    所述第二低通滤波电路向所述比较电路输入判决门限电信号；
    所述比较电路向所述微处理器输出第三低频电信号。
  7. 如权利要求6所述的光模块，其特征在于，还包括电路板，所述光接收芯片、所述升压镜像电路、所述跨阻放大芯片、所述限幅放大芯片、所述第一低通滤波电路、所述第二低通滤波电路、所述比较电路及所述微处理器分别设置在所述电路板上。
  8. 如权利要求6所述的光模块，其特征在于，还包括电路板及独立封装体；所述独立封装体与所述电路板电连接；
    所述限幅放大芯片、所述第一低通滤波电路、所述第二低通滤波电路、所述比较电路及所述微处理器分别设置在所述电路板上；
    所述光接收芯片、所述升压镜像电路及所述跨阻放大芯片分别设置在所述独立封装体中。
  9. 如权利要求6所述的光模块，其特征在于，在所述升压镜像电路与所述第一低通滤波电路之间接入电容及直流输出电源。
  10. 如权利要求6所述的光模块，其特征在于，所述第二滤波电路与所述比较电路之间接入隔离电路。
  11. 一种光模块，其特征在于，包括
    光接收芯片，一端通过分压电阻电连接至升压电路，另一端与跨阻放大芯片电连接，接收高低频混合的光信号；
    减法放大电路，从所述分压电阻的两端分别接收电压信号，输出端与第二低通滤波电路的输入端电连接；
    所述第二低通滤波电路的输入端还与比较电路的第一输入端电连接，输出端与 所述比较电路的第二输入端电连接，输出判决门限电信号；
    所述比较电路的输出端与微处理器电连接，输出低频数字电信号；
    所述跨阻放大芯片与限幅放大芯片电连接，所述限幅放大芯片输出高频电信号。
  12. 如权利要求12所述的光模块，其特征在于，所述分压电阻与所述减法放大电路之间还包括高频滤波电路；所述高频滤波电路具体为RC电路，所述分压电阻的两端分别连接一个RC电路。
  13. 如权利要求11所述的光模块，其特征在于，还包括高频滤波电路，
    所述高频滤波电路的输入端与所述减法放大电路的输出端电连接，输出端分别与所述第二低通滤波电路的输入端及所述比较电路的第一输入端电连接；
    所述高频滤波电路具体为RC电路。
  14. 如权利要求11所述的光模块，其特征在于，所述分压电阻与所述减法放大电路之间电连接有电容，所述分压电阻的两端分别连接一个所述电容。
  15. 如权利要求14所述的光模块，其特征在于，所述第二低通滤波电路的输入端还与直流电源电连接。
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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115658577A (zh) * 2022-10-28 2023-01-31 维沃移动通信有限公司 接口模组和电子设备

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN116232449B (zh) * 2023-03-09 2025-07-04 成都蓉博通信技术有限公司 一种检测光接收机接收信号强度和信号丢失的检测电路
CN116667934B (zh) * 2023-06-20 2026-02-17 四川华丰科技股份有限公司 一种信号传输方法及光模块

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5112134A (en) * 1984-03-01 1992-05-12 Molecular Devices Corporation Single source multi-site photometric measurement system
CN1691549A (zh) * 2004-03-29 2005-11-02 夏普株式会社 光接收机
CN104967487A (zh) * 2015-07-24 2015-10-07 武汉光迅科技股份有限公司 一种基于频率调制的带内透传监控信号的光模块
CN104980225A (zh) * 2015-07-24 2015-10-14 武汉光迅科技股份有限公司 一种基于幅度调制的带内透传监控信号的光模块
CN204761443U (zh) * 2015-07-24 2015-11-11 武汉光迅科技股份有限公司 一种基于频率调制的带内透传监控信号的光模块
CN204993356U (zh) * 2015-07-24 2016-01-20 武汉光迅科技股份有限公司 一种基于幅度调制的带内透传监控信号的光模块
CN106559143A (zh) * 2015-09-29 2017-04-05 青岛海信宽带多媒体技术有限公司 光模块

Family Cites Families (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN201188619Y (zh) * 2008-05-06 2009-01-28 深圳新飞通光电子技术有限公司 一种高速数字光模块接收电路
CN102025415B (zh) * 2009-09-18 2013-12-04 华为技术有限公司 速率检测方法及装置
CN102723998B (zh) * 2012-05-29 2015-06-17 武汉电信器件有限公司 一种延时干涉仪工作点的控制装置及其控制方法
JP6334183B2 (ja) * 2014-01-31 2018-05-30 株式会社日立製作所 光伝送回路
CN104320200B (zh) * 2014-11-17 2016-11-16 索尔思光电（成都）有限公司 保护apd接收器的电路、光模块及方法
KR101906592B1 (ko) * 2014-11-27 2018-10-12 한국전자통신연구원 광모듈
JP6613564B2 (ja) * 2014-12-26 2019-12-04 セイコーエプソン株式会社 光学フィルターデバイス、光学モジュール、及び電子機器
CN106019292B (zh) * 2016-05-12 2018-04-20 常州大地测绘科技有限公司 相位式激光测距仪用激光接收电路
CN106375058A (zh) * 2016-09-09 2017-02-01 青岛海信宽带多媒体技术有限公司 光模块
CN108768533B (zh) * 2018-06-27 2024-04-19 深圳虹鹰科技有限公司 一种用于高速远距离传输的光收发一体组件
CN109099942A (zh) * 2018-07-11 2018-12-28 厦门中莘光电科技有限公司 一种集成硅基光电探测器的光电模数转换芯片
CN109412013B (zh) * 2018-11-09 2023-08-08 武汉联特科技股份有限公司 一种波长可调谐光模块、远程波长切换方法及锁定方法
CN109495185B (zh) * 2018-11-14 2020-12-22 青岛海信宽带多媒体技术有限公司 光模块

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5112134A (en) * 1984-03-01 1992-05-12 Molecular Devices Corporation Single source multi-site photometric measurement system
CN1691549A (zh) * 2004-03-29 2005-11-02 夏普株式会社 光接收机
CN104967487A (zh) * 2015-07-24 2015-10-07 武汉光迅科技股份有限公司 一种基于频率调制的带内透传监控信号的光模块
CN104980225A (zh) * 2015-07-24 2015-10-14 武汉光迅科技股份有限公司 一种基于幅度调制的带内透传监控信号的光模块
CN204761443U (zh) * 2015-07-24 2015-11-11 武汉光迅科技股份有限公司 一种基于频率调制的带内透传监控信号的光模块
CN204993356U (zh) * 2015-07-24 2016-01-20 武汉光迅科技股份有限公司 一种基于幅度调制的带内透传监控信号的光模块
CN106559143A (zh) * 2015-09-29 2017-04-05 青岛海信宽带多媒体技术有限公司 光模块

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115658577A (zh) * 2022-10-28 2023-01-31 维沃移动通信有限公司 接口模组和电子设备

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