Optical module and superordinate computer thereof
By combining digital equalization and analog equalization techniques in optical modules, the problems of high power consumption and high latency in optical modules in ultra-large-scale data centers and artificial intelligence/machine learning applications have been solved, achieving high-bandwidth, low-power, and low-cost optical signal transmission.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- HISENSE BROADBAND MULTIMEDIA TECH
- Filing Date
- 2024-12-18
- Publication Date
- 2026-05-15
AI Technical Summary
Existing optical modules are insufficient to meet the demands for high bandwidth, low power consumption, low latency, and low cost in hyperscale data centers and artificial intelligence/machine learning applications, especially due to the high power consumption, high latency, and high cost issues caused by digital signal processing chips.
A scheme combining digital and analog equalization is adopted. The high-speed digital electrical signal is pre-compensated by the digital equalizer, and then the electrical signal quality is further optimized by the analog equalizer to reduce transmission loss and improve signal discrimination, thereby reducing the complexity and resource consumption of optical signal processing.
It effectively reduces the power consumption and latency of optical modules, improves signal transmission quality, meets users' needs for low power consumption, low latency and low cost, while ensuring efficient conversion and transmission of electrical signals.
Smart Images
Figure CN2024140391_15052026_PF_FP_ABST
Abstract
Description
Optical module and its host computer
[0001] This application claims priority to Chinese Patent Application No. 202411586824.1, filed on November 7, 2024; the entire contents of which are incorporated herein by reference. Technical Field
[0002] This disclosure relates to the field of optical fiber communication technology, and in particular to an optical module and a host computer for the optical module. Background Technology
[0003] With the rise of hyperscale data centers and artificial intelligence (AI) / machine learning (ML) application environments, users have raised demands for optical modules with characteristics such as high bandwidth, low power consumption, low latency, and low cost. Because the amount of data to be transmitted is enormous, optical modules need to have high transmission bandwidth; however, the transmission bandwidth of a single optical module is limited, so multiple optical modules are combined to expand the transmission bandwidth. However, increasing the number of optical modules leads to a negative increase in power consumption and cost; at the same time, the high-speed data transmission requirements also necessitate further reductions in latency, and current optical modules are insufficient to fully meet user needs. Summary of the Invention
[0004] This disclosure provides an optical module, including: a circuit board with an electrical connector disposed on its surface; the electrical connector is connected to a high-speed data electrical signal from a host computer;
[0005] The optical module also includes an analog equalizer, which is mounted on the surface of the circuit board and its input is electrically connected to the electrical connector. It is used to receive high-speed analog signals when the high-speed data signal is a high-speed analog signal. The analog equalizer is also used to perform analog equalization on the high-speed analog signal.
[0006] Alternatively, the optical module may also include a digital equalizer, a digital-to-analog converter, and an analog equalizer. The digital equalizer is mounted on the surface of the circuit board, and its input is electrically connected to an electrical connector. It is used to receive high-speed digital signals when the high-speed data signal is a high-speed digital signal. The digital equalizer is also used to perform digital equalization on the high-speed digital signal. The digital-to-analog converter is mounted on the surface of the circuit board, and its input is electrically connected to the output of the digital equalizer. It receives the digitally equalized high-speed digital signal and converts the received high-speed digital signal into a high-speed analog signal. The analog equalizer is mounted on the surface of the circuit board, and its input is electrically connected to the output of the digital-to-analog converter. The analog equalizer is used to receive high-speed analog signals and perform analog equalization on the high-speed analog signals.
[0007] The laser driver chip is mounted on the surface of the circuit board. Its input terminal is electrically connected to the output terminal of the analog equalizer. It receives the high-speed analog electrical signal after analog equalization and generates a modulated electrical signal.
[0008] The laser chip or optical modulation chip has its input terminal electrically connected to the output terminal of the laser driver chip, receiving the modulation electrical signal and outputting the optical signal.
[0009] This disclosure also provides a host computer for an optical module, including a PAM4 chip / NRZ chip, which outputs high-speed digital electrical signals;
[0010] The host computer also includes a digital equalizer and a digital-to-analog converter. The input of the digital equalizer is electrically connected to the PAM4 chip / NRZ chip to receive high-speed digital electrical signals. The digital equalizer is used to perform digital equalization on the high-speed digital electrical signals. The input of the digital-to-analog converter is electrically connected to the output of the digital equalizer to receive the digitally equalized high-speed digital electrical signals. The digital-to-analog converter is used to convert the received high-speed digital electrical signals into high-speed analog electrical signals.
[0011] Alternatively, the host computer may also include a digital equalizer, a digital-to-analog converter, and an analog equalizer. The input of the digital equalizer is electrically connected to the PAM4 chip / NRZ chip to receive high-speed digital signals, and the digital equalizer is used to perform digital equalization on the high-speed digital signals. The input of the digital-to-analog converter is electrically connected to the output of the digital equalizer to receive the digitally equalized high-speed digital signals, and the digital-to-analog converter is used to convert the received high-speed digital signals into high-speed analog signals. The input of the analog equalizer is electrically connected to the output of the digital-to-analog converter to receive high-speed analog signals, and the analog equalizer is used to perform analog equalization on the high-speed analog signals.
[0012] The electrical connector connects to the analog equalizer, transmitting the high-speed analog electrical signal, which has undergone digital and analog equalization, to the optical module. Attached Figure Description
[0013] To more clearly illustrate the technical solutions in this disclosure, the accompanying drawings used in some embodiments of this disclosure will be briefly introduced below. Obviously, the drawings described below are only drawings of some embodiments of this disclosure, and those skilled in the art can obtain other drawings based on these drawings. In addition, the drawings described below can be regarded as schematic diagrams and are not intended to limit the actual size of the product, the actual flow of the method, the actual timing of the signals, etc. involved in the embodiments of this disclosure.
[0014] Figure 1 is a partial structural diagram of an optical communication system according to some embodiments;
[0015] Figure 2 is a partial structural diagram of a host computer according to some embodiments;
[0016] Figure 3 is a structural diagram of an optical module according to some embodiments;
[0017] Figure 4 is an exploded view of an optical module according to some embodiments;
[0018] Figure 5 is an internal structural diagram of an optical module according to some embodiments;
[0019] Figure 6 is a diagram showing the electrical signal connection between an optical module and a host computer according to some embodiments;
[0020] Figure 7 is a diagram showing the electrical connection relationship between an optical module and a host computer according to some embodiments;
[0021] Figure 8 is a diagram showing the electrical connection between another optical module and a host computer according to some embodiments. Detailed Implementation
[0022] The embodiments of this disclosure will now be described clearly and in detail with reference to the accompanying drawings. However, the described embodiments are merely some, and not all, of the embodiments of this disclosure. All other embodiments obtained by those skilled in the art based on the embodiments provided in this disclosure are within the scope of protection of this disclosure.
[0023] Unless the context otherwise requires, throughout the specification and claims, the term "comprising" is interpreted as open and inclusive, meaning "including, but not limited to"; the terms "first" and "second" should not be construed as indicating or implying relative importance or indicating an upper limit on the number; the term "multiple" means two or more; the term "connection" should be interpreted broadly, for example, "connection" can be a fixed connection, a detachable connection, or an integral part, and can be a direct connection or an indirect connection through an intermediate medium; the use of the terms "applicable to" or "configured to" implies open and inclusive language, which does not exclude applicability to or configuration to devices performing additional tasks or steps; descriptions such as "parallel," "perpendicular," "identical," "consistent," and "aligned" are not limited to absolute mathematical theoretical relationships, but also include acceptable error ranges arising in practice, and differences based on the same design concept but due to manufacturing reasons.
[0024] In optical communication technology, to establish information transmission between information processing devices, information is loaded onto light, and the speed of light propagation is used to transmit the information. This light carrying information is called an optical signal. When optical signals are transmitted in optical information transmission equipment, optical power loss can be reduced, enabling long-distance transmission of optical signals. At the same time, the cost of optical information transmission equipment such as optical fibers is lower than that of electrical information transmission equipment such as copper wires. Therefore, optical communication technology can achieve high-speed, long-distance, and low-cost information transmission.
[0025] Information processing equipment typically includes optical network units (ONUs), gateways, routers, switches, mobile phones, computers, servers, tablets, televisions, etc., while optical information transmission equipment typically includes optical fibers and optical waveguides. Information processing equipment can only recognize and process electrical signals, while optical communication technology uses optical signals for transmission, requiring optical modules to convert between optical and electrical signals.
[0026] An optical module enables the conversion between optical signals and electrical signals between information processing equipment and optical information transmission equipment. In some embodiments, at least one of the optical signal input or output terminals of the optical module is connected to an optical fiber, and at least one of the electrical signal input or output terminals of the optical module is connected to an optical network terminal. A first optical signal from the optical fiber is transmitted to the optical module, which converts the first optical signal into a first electrical signal and transmits the first electrical signal to the optical network terminal. A second electrical signal from the optical network terminal is transmitted to the optical module, which converts the second electrical signal into a second optical signal and transmits the second optical signal to the optical fiber.
[0027] Since multiple information processing devices can transmit information via electrical signals, at least one of these devices needs to be directly connected to the optical module, rather than all of them. Here, the information processing device directly connected to the optical module is also referred to as the host computer of the optical module. Furthermore, the optical signal input or output terminal of the optical module is called the optical port, and the electrical signal input or output terminal is called the electrical port.
[0028] Figure 1 is a partial structural diagram of an optical communication system according to some embodiments. As shown in Figure 1, the optical communication system mainly includes a remote information processing device 1000, a local information processing device 2000, a host computer 100 for optical modules, an optical module 200, an optical fiber 101, and a network cable 103, wherein the optical fiber 101 is an optical information transmission device, and the network cable 103 is an electrical information transmission device.
[0029] In some embodiments, one end of the optical fiber 101 extends toward the remote information processing device 1000, and the other end of the optical fiber 101 is connected to the optical module 200 through the optical port of the optical module 200. The optical signal can undergo total internal reflection in the optical fiber 101, and the propagation of the optical signal in the direction of total internal reflection can almost maintain the original optical power. The optical signal undergoes multiple total internal reflections in the optical fiber 101 to transmit the optical signal from the remote information processing device 1000 to the optical module 200, or to transmit the optical signal from the optical module 200 to the remote information processing device 1000, thereby realizing long-distance information transmission based on low power loss.
[0030] The optical communication system includes one or more optical fibers 101. In some embodiments, the optical fiber 101 is detachably connected to the optical module 200; in some embodiments, the optical fiber 101 is non-detachably connected to the optical module 200.
[0031] The host computer 100 is configured to provide data signals to the optical module 200, or receive data signals from the optical module 200, or monitor or control the working status of the optical module 200.
[0032] The host computer 100 includes a housing for accommodating the optical module 200, and an optical module interface 102 disposed on the housing. The optical module 200 is inserted into the housing through the optical module interface 102 to establish a unidirectional or bidirectional electrical signal connection between the host computer 100 and the optical module 200.
[0033] The host computer 100 also includes an external power interface that can connect to an electrical signal network. In some embodiments, the external power interface includes a Universal Serial Bus (USB) interface or a network cable interface 104. The network cable interface 104 is configured to connect a network cable 103 to establish a unidirectional or bidirectional electrical signal connection between the host computer 100 and the network cable 103.
[0034] One end of the network cable 103 is connected to the local information processing device 2000, and the other end is connected to the host computer 100, so as to establish an electrical signal connection between the local information processing device 2000 and the host computer 100 through the network cable 103. In some embodiments, a third electrical signal emitted by the local information processing device 2000 is transmitted to the host computer 100 through the network cable 103. The host computer 100 generates a second electrical signal based on the third electrical signal. The second electrical signal from the host computer 100 is transmitted to the optical module 200. The optical module 200 converts the second electrical signal into a second optical signal and transmits the second optical signal to the optical fiber 101. The second optical signal is transmitted in the optical fiber 101 to the remote information processing device 1000.
[0035] In some embodiments, a first optical signal from a remote information processing device 1000 is transmitted through an optical fiber 101, and the first optical signal from the optical fiber 101 is transmitted to an optical module 200. The optical module 200 converts the first optical signal into a first electrical signal, and transmits the first electrical signal to a host computer 100. The host computer 100 generates a fourth electrical signal based on the first electrical signal and transmits the fourth electrical signal to a local information processing device 2000.
[0036] In some embodiments, the optical module 200 is a tool for converting optical signals to electrical signals. During the conversion process, the information does not change, but the encoding or decoding method of the information changes.
[0037] In addition to optical network terminals, the host computer 100 also includes optical line terminals (OLTs), optical network equipment (ONTs), or data center servers.
[0038] Figure 2 is a partial structural diagram of a host computer according to some embodiments. To clearly show the connection relationship between the optical module 200 and the host computer 100, Figure 2 only shows the structure of the host computer 100 related to the optical module 200. As shown in Figure 2, in some embodiments, the host computer 100 further includes a PCB circuit board 105 disposed in a receiving cavity, and a cage 106 disposed on the surface of the PCB circuit board 105; the optical module 200 is inserted into the cage 106 and fixed by the cage 106;
[0039] In some embodiments, a heat sink 107 is provided on the cage 106 to dissipate heat for the optical module 200; in some embodiments, the heat sink 107 has fins or other protruding structures to increase the heat dissipation area.
[0040] In some embodiments, an electrical connector is provided inside the cage 106, which is configured to connect to the electrical port of the optical module 200.
[0041] In some embodiments, the optical module 200 is inserted into the cage 106 of the host computer 100, and the cage 106 fixes the optical module 200. The heat generated by the optical module 200 is conducted to the cage 106 and then diffused through the heat sink 107.
[0042] In some embodiments, the optical module 200 is inserted into the cage 106 of the host computer 100, and the electrical port of the optical module 200 is connected to the electrical connector inside the cage 106, thereby establishing an electrical signal connection between the optical module 200 and the host computer 100.
[0043] In some embodiments, the optical port of the optical module 200 is connected to the optical fiber 101, thereby enabling the optical module 200 to establish an optical signal connection with the optical fiber 101.
[0044] Figure 3 is a structural diagram of an optical module according to some embodiments, and Figure 4 is an exploded view of an optical module according to some embodiments. As shown in Figures 3 and 4, in some embodiments, the optical module 200 includes a shell, which includes an upper shell 201 and a lower shell 202. The upper shell 201 covers the lower shell 202, forming two openings 204 and 205, one of which is an electrical port and the other is an optical port. In some embodiments, the shell forms an opening that serves as both an electrical port and an optical port.
[0045] In some embodiments, the upper housing 201 and the lower housing 202 are made of metal materials, which facilitates electromagnetic shielding and heat dissipation.
[0046] The assembly method of combining the upper housing 201 and the lower housing 202 facilitates the installation of the circuit board 300, the light emitting component 400, the light receiving component 500, etc. into the housing. The upper housing 201 and the lower housing 202 can encapsulate and protect the above-mentioned devices.
[0047] The direction of the line connecting the two openings 204 and 205 can be consistent with or inconsistent with the length direction of the optical module 200. For example, opening 204 is located at the end of the optical module 200 (right end in Figure 3), and opening 205 is also located at the end of the optical module 200 (left end in Figure 3). Alternatively, opening 204 is located at the end of the optical module 200, while opening 205 is located on the side of the optical module 200.
[0048] In some embodiments, the lower housing 202 includes a base plate 2021 and two lower side plates 2022 located on both sides of the base plate 2021 and perpendicular to the base plate 2021; the upper housing 201 includes a cover plate 2011, which covers the two lower side plates 2022 of the lower housing 202 to form the aforementioned housing.
[0049] In some embodiments, the lower housing 202 includes a base plate 2021 and two lower side plates 2022 located on both sides of the base plate 2021 and perpendicular to the base plate 2021; the upper housing 201 includes a cover plate 2011 and two upper side plates located on both sides of the cover plate 2011 and perpendicular to the cover plate 2011. The two upper side plates and the two lower side plates 2022 are combined to realize that the upper housing 201 covers the lower housing 202.
[0050] As shown in Figures 3 and 4, in some embodiments, the optical module 200 includes a circuit board 300 disposed within a housing. The circuit board 300 includes circuit traces, electronic components, and chips, etc. The electronic components and chips are connected according to the circuit design through the circuit traces to realize functions such as power supply, electrical signal transmission, and grounding. Electronic components may include, for example, capacitors, resistors, transistors, and metal-oxide-semiconductor field-effect transistors (MOSFETs). Chips may include one or more of the following: a microcontroller unit (MCU), a laser driver chip, a transimpedance amplifier (TIA), a limiting amplifier (LA), and a power management chip.
[0051] The host computer 100 sends high-speed data signals to the optical module 200, which converts the high-speed data signals into optical signals. These optical signals are then propagated in the optical fiber / cable to achieve data transmission with the remote end. The optical module 200 receives optical signals from the optical fiber / cable, converts them into high-speed data signals, and sends these high-speed data signals to the host computer 100. An electrical connection is established between the optical module 200 and the host computer 100 to achieve bidirectional transmission of high-speed data signals.
[0052] The circuit board of the optical module 200 is equipped with an electrical connector to establish an electrical connection with the host computer 100; the electrical connector can be an electrical connection pin or a pin header.
[0053] In some embodiments, the optical module 200 includes a circuit board with electrical connection pins. By inserting these pins into the electrical connector of a host computer, bidirectional transmission of high-speed data signals is achieved. The circuit board can be a rigid circuit board (PCB) or a flexible circuit board (FPC). The electrical connection pins can be gold finger-type pins disposed on the surface of the circuit board, each consisting of multiple independent pins.
[0054] In some embodiments, the optical module has a circuit board with pads on it and pins soldered onto the pads. By establishing an electrical connection between the pins and a host computer, high-speed bidirectional data signal transmission between the optical module and the host computer can be achieved. The circuit board can be a rigid circuit board (PCB) or a flexible circuit board (FPC).
[0055] In some embodiments, the circuit board includes a rigid circuit board, which, due to its relatively rigid material, can also serve a load-bearing function, such as being able to stably support the aforementioned electronic components and chips; the rigid circuit board can also be inserted into an electrical connector in the cage 106 of the host computer 100.
[0056] In some embodiments, the circuit board 300 further includes gold fingers 301 formed on its end surface, the gold fingers 301 being composed of a plurality of independent pins. In some embodiments, the gold fingers 301 are disposed on one side of the surface of the circuit board 300 (e.g., the upper surface shown in FIG. 4); in some embodiments, the gold fingers 301 are disposed on the upper and lower surfaces of the circuit board 300 to provide a greater number of pins, thereby adapting to applications with a large number of pins required.
[0057] In some implementations, the gold fingers 301 of the circuit board 300 extend from the electrical port 204 and are inserted into the electrical connector of the host computer 100; the circuit board 300 is inserted into the cage 106, and the gold fingers 301 are connected to the electrical connector inside the cage 106. The gold fingers 301 are configured to establish an electrical connection with the host computer 100, enabling electrical connection functions such as power supply, grounding, two-wire synchronous serial (Inter-Integrated Circuit, I2C) signal transmission, and data signal transmission.
[0058] In some embodiments, the optical module 200 further includes an unlocking component 600 located outside its housing. The unlocking component 600 is configured to establish a fixed connection between the optical module 200 and the host computer, or to release the fixed connection between the optical module 200 and the host computer.
[0059] For example, the unlocking component 600 is located on the outside of the two lower side plates 2022 of the lower housing 202, and includes a locking component that matches the cage 106 of the host computer 100. When the optical module 200 is inserted into the cage 106, the locking component of the unlocking component 600 fixes the optical module 200 in the cage 106; when the unlocking component 600 is pulled, the locking component of the unlocking component 600 moves accordingly, thereby changing the connection relationship between the locking component and the host computer, so as to release the fixation between the optical module 200 and the host computer, thereby allowing the optical module 200 to be pulled out of the cage 106.
[0060] In some embodiments, the optical module includes an optical emitting component 400, as shown in FIG4. The optical emitting component 400 is used to emit optical signals.
[0061] In some embodiments, the optical module includes an optical receiving component 500, as shown in FIG4. The optical receiving component 500 is used to receive optical signals and convert the optical signals into electrical signals.
[0062] In some embodiments, at least one of the light emitting component 400 or the light receiving component 500 is located on the side of the circuit board 300 away from the gold fingers.
[0063] In some embodiments, the light emitting component 400 and the light receiving component 500 are physically separated from the circuit board 300, and then electrically connected to the circuit board 300 through corresponding flexible circuit boards or electrical connectors.
[0064] In some embodiments, at least one of the light emitting component or the light receiving component may be directly disposed on the circuit board 300. For example, at least one of the light emitting component or the light receiving component may be disposed on the surface of the circuit board 300 or the side of the circuit board 300.
[0065] In some embodiments, the circuit board 300 further includes a first fiber optic adapter 700 at its end.
[0066] In some embodiments, the circuit board 300 further includes a second fiber optic adapter 800 at its end.
[0067] In some examples, the second fiber optic adapter 800 and the first fiber optic adapter 700 are arranged side by side at the end of the circuit board 300.
[0068] Figure 5 is an internal structural diagram of an optical module according to some embodiments. In some embodiments, an analog equalizer 310 may be disposed on the surface of the circuit board 300. The analog equalizer 310 can process electrical signals transmitted from the host computer 100 through the gold finger 301, and can also process electrical signals transmitted from the optical receiving component 500 to the gold finger 301.
[0069] In some implementations, a laser driver chip can be provided on the surface of the circuit board 300. One end of the laser driver chip can be connected to the analog equalizer 310, and the other end of the laser driver chip can be connected to the light emitting component 400, so that the laser driver chip provides a high-frequency drive signal under the action of the electrical signal processed by the analog equalizer 310, thereby causing the light emitting component 400 to emit a light signal under the action of the high-frequency drive signal.
[0070] In some embodiments, the optical receiver 500 can be connected to the analog equalizer 310 via a second signal line, so that the analog equalizer 310 can process the high-frequency electrical signal transmitted from the optical receiver 500 to the gold finger via the second signal line. For example, the transimpedance amplifier chip of the optical receiver 500 can be connected to the analog equalizer 310 via the second signal line.
[0071] In some embodiments, the light emitting component 400 and the light receiving component 500 are staggered along the length of the circuit board 300, and the light emitting component 400 and the light receiving component 500 have no overlapping portion along the width of the circuit board 300. The light receiving component 500 and the analog equalizer 310 are located on the same surface of the circuit board 300.
[0072] In some embodiments, the light receiving component 500 may include a first light receiving component 502. The first light receiving component 502 may be located on one side of the light emitting component 400. The first light receiving component 502 may be disposed on the surface of the circuit board 300. For example, the first light receiving component 502 is located on the upper surface of the circuit board 300.
[0073] The light receiving component 500 may include a second light receiving component 501. The second light receiving component 501 may be located on the other side of the light emitting component 400. The second light receiving component 501 may be disposed on the surface of the circuit board 300. For example, the second light receiving component 501 may be disposed on the upper surface of the circuit board 300.
[0074] As shown in Figure 5, taking a rigid PCB as an example, gold fingers are provided on one end surface of the PCB. The gold fingers are inserted into the host computer to receive high-speed data signals from the host computer.
[0075] A laser driver chip is placed on the surface of a rigid circuit board. The laser driver chip provides electrical signals to the laser chip to drive the laser chip to emit light signals.
[0076] In hyperscale data centers and AI / ML application environments, users have raised demands for optical modules with characteristics such as high bandwidth, low power consumption, low latency, and low cost. Because the amount of data to be transmitted in these environments is enormous, optical modules require high transmission bandwidth. However, the transmission bandwidth of a single optical module is limited, so multiple optical modules are combined to expand the bandwidth. However, increasing the number of optical modules leads to a negative increase in power consumption and cost. At the same time, the high-speed data transmission requirements necessitate further reductions in latency, and current optical modules are insufficient to fully meet user needs.
[0077] During the development of optical modules, the applicant discovered that the Digital Signal Processing (DSP) chip is one of the key factors affecting power consumption, latency, and cost in optical modules. The applicant's research shows that in an 800G optical module based on 100G / channel and 8 optical channels, the DSP accounts for more than 50% of the total power consumption; in a 1.6T optical module based on 200G / channel and 8 optical channels, the DSP accounts for more than 60% of the total power consumption. Furthermore, the DSP also leads to high latency, thus limiting the use of DSP-based optical modules in AI / ML applications.
[0078] In optical modules, DSPs are mainly used to recover distorted electrical signals. Whether the electrical signals come from the host computer or from the received light after conversion, these electrical signals have obvious signal distortion. Electrical signal distortion will cause system errors and affect the quality of data transmission.
[0079] DSPs play a crucial role in recovering electrical signals in optical modules, but they also bring problems such as high power consumption, high cost, and high latency. Therefore, removing DSPs from optical modules can meet users' needs for low power consumption, low latency, and low cost, but ensuring the quality of electrical signals at the same time becomes a technical problem that needs to be solved.
[0080] The optical signal emitted by the optical module is based on the electrical signal from the host computer. During the transmission of the electrical signal from the host computer to the optical module, the adverse phenomenon of electrical signal distortion may occur. After analyzing the transmission path and transmission results of the electrical signal, the applicant found that the distortion of the electrical signal is mainly manifested in the reduction of the amplitude of the high-frequency part of the electrical signal, which weakens the amplitude difference between the high-frequency part and the low-frequency part, thus reducing the distinguishability between the high-frequency part and the low-frequency part of the signal, making it impossible to extract data from the electrical signal, resulting in the phenomenon of electrical signal distortion.
[0081] In response, the applicant provides an electrical signal equalization scheme that reduces or eliminates losses during electrical signal transmission by equalizing the electrical signal, so that the electrical signal after transmission loss maintains a high degree of high and low frequency differentiation, and the amplitude difference between the high-frequency and low-frequency components of the electrical signal is sufficient to resolve the data.
[0082] In some embodiments, the laser driver chip needs to be input with an analog signal / the optical module uses an analog signal to drive the laser chip to emit light, while the host computer of the optical module processes digital signals. In response, the applicant provides a solution that combines digital equalization and analog equalization to improve the compensation effect on electrical signals.
[0083] In some embodiments, when only digital equalization is used to compensate for low modulation bandwidth and / or high RF connection loss, the performance will be limited due to the influence of peak-to-average power ratio (PAPR). To address this, the applicant provides a scheme that combines digital equalization and analog equalization to improve the compensation effect on electrical signals.
[0084] Figure 6 is a diagram showing the electrical connection between an optical module and a host computer according to some embodiments. In some embodiments, as shown in Figure 6, the host computer / Serdes 100 includes a PAM4 chip / NRZ chip 111, which outputs a high-speed data electrical signal to the optical module 200; the output of the PAM4 chip / NRZ chip 111 is a high-speed digital electrical signal, which can also be converted into a high-speed analog electrical signal.
[0085] In some embodiments, as shown in FIG6, the host computer / Serdes100 includes a digital equalizer 112, which can perform equalization compensation on high-speed digital electrical signals. The digital equalizer 112 can be an FFE (Feed Forward Equalizer) chip or a DFE (Decision Feedback Equalizer) chip.
[0086] The electrical signal obtained after the high-speed digital electrical signal is equalized by the digital equalizer 112 is significantly different from the initial electrical signal in the host computer / Serdes (such as the high-speed data electrical signal output by the PAM4 chip / NRZ chip). The digital equalizer 112 reduces the amplitude of the low-frequency part of the digital electrical signal and can also extend the bandwidth of the high-speed digital electrical signal.
[0087] The DSP restores the electrical signal, for example, restoring it to the state it was in when the PAM4 chip / NRZ chip was output. Unlike the DSP, the digital equalizer 112 does not restore the signal; instead, it pre-improves the signal to account for subsequent losses. Compared to restoring distorted electrical signals, the digital equalizer 112 pre-compensates for the original quality electrical signal based on subsequent losses, effectively offsetting the losses incurred during optical signal transmission, improving the transmission quality of the optical signal, reducing the complexity and resource consumption of subsequent optical signal processing, and thus improving the overall working efficiency of the host computer 100 and the optical module 200.
[0088] The processing effect of the digital equalizer 112 can be adjusted by adjusting the tap factor (TAP). By monitoring the emission dispersion eye diagram closed four-phase TDECQ parameters of the output optical signal, the tap factor (TAP) can be adjusted to obtain a more suitable tap factor (TAP).
[0089] In some embodiments, as shown in FIG6, the input terminal of the digital equalizer 112 is electrically connected to the PAM4 chip / NRZ chip 111 to receive high-speed data electrical signals. At this time, the high-speed data electrical signals are high-speed digital electrical signals, and the digital equalizer 112 performs equalization compensation on the high-speed digital electrical signals. The output terminal of the digital equalizer 112 is electrically connected to the digital-to-analog signal converter (DAC) 113 to transmit the digitally equalized electrical signals to the DAC 113.
[0090] In some embodiments, as shown in FIG6, the host computer / Serdes includes a DAC 113, which can convert digital electrical signals into analog electrical signals. In some embodiments, the input terminal of the DAC 113 is electrically connected to the output terminal of the digital equalizer 112 to receive the digitally equalized digital electrical signal, which is then converted into an analog electrical signal by the DAC 113, and the output terminal of the DAC 113 outputs the analog electrical signal.
[0091] The electrical signals output by the PAM4 / NRZ chips carry the data required for the optical signal transmission to the optical module 200. The PAM4 / NRZ chips are the data source, and their output electrical signals are of high quality. During transmission, electrical signals experience loss. Before reaching the optical module 200, the electrical signals output by the PAM4 / NRZ chips undergo digital equalization / compensation. This equalization / compensation, performed when the signal quality is high, improves the signal quality retained after loss, providing a better foundation for subsequent analog equalization / compensation. For severely attenuated electrical signals, the data signal is difficult to distinguish due to its low quality. Therefore, even with equalization / compensation, it is difficult to recover the data. Thus, equalization must be performed when the signal quality is high.
[0092] After the electrical signal is digitally compensated by the digital equalizer 112, the quality of the lost electrical signal can be improved. However, when only digital equalization is used to compensate for low modulation bandwidth and / or high RF connection loss, the performance will be limited due to the influence of peak-to-average power ratio (PAPR). Therefore, it is necessary to combine digital equalization with analog equalization.
[0093] In some embodiments, as shown in FIG6, the host computer / Serdes includes an analog equalizer 310, which can reduce the amplitude of the low-frequency part of the analog electrical signal. The analog equalizer 310 is a circuit composed of resistors, inductors, capacitors, etc. By adjusting the resistance, inductance, or capacitance values of the circuit, the equalization effect of the analog equalizer 310 can be adjusted.
[0094] In some embodiments, the analog equalizer 310 in the host computer can be an active analog equalizer, which can boost the high-frequency portion of the analog electrical signal. The active analog equalizer includes an amplifier, and the equalization effect can be adjusted by controlling the amplifier gain.
[0095] In some embodiments, the input of the analog equalizer 310 is electrically connected to the DAC 310, and its output provides an equalized high-speed analog electrical signal to the optical module.
[0096] Due to the influence of peak-to-average power ratio (PAPR), the equalization performance of digital equalizer 112 is limited. The performance defects of digital equalizer can be compensated by analog equalizer 310 continuing to equalize the digitally equalized electrical signal.
[0097] In some embodiments, as shown in FIG6, the optical module 200 includes an electrical connector 211 disposed on the surface of the circuit board 300. The high-speed analog electrical signal output by the analog equalizer 310 is connected through the electrical connection pin / electrical connector 211, and the high-speed analog electrical signal is transmitted to the laser driver chip 213 by the electrical connector 211.
[0098] In some embodiments, as shown in FIG6, the optical module 200 includes a laser driver chip 213 disposed on the surface of the circuit board 300. The laser driver chip 213 can output a modulation signal according to a high-speed analog electrical signal to complete the modulation of the optical signal. The input terminal of the laser driver chip 213 is electrically connected to the electrical connector 211.
[0099] In some embodiments, the optical module 200 includes a laser chip or an optical modulation chip, the input of which is electrically connected to the output of the laser driver chip 213, to receive the modulation electrical signal and output an optical signal.
[0100] Figure 7 is a diagram showing the electrical connection between an optical module and a host computer according to some embodiments. As shown in Figure 7, in some embodiments, the optical module 200 includes a digital equalizer 112, which can perform equalization compensation on high-speed digital electrical signals. The digital equalizer 112 can be an FFE (Feed Forward Equalizer) chip or a DFE (Decision Feedback Equalizer) chip.
[0101] The electrical signal obtained after the high-speed digital electrical signal is equalized by the digital equalizer 112 is significantly different from the initial electrical signal in the host computer / Serdes (such as the high-speed data electrical signal output by the PAM4 chip / NRZ chip). The digital equalizer 112 reduces the amplitude of the low-frequency part of the digital electrical signal and can also extend the bandwidth of the high-speed digital electrical signal.
[0102] DSPs restore electrical signals, for example, restoring them to the state they were in when output by a PAM4 chip / NRZ chip. Unlike DSPs, digital equalizers do not restore signals; instead, they pre-improve them to account for subsequent losses.
[0103] The processing effect of a digital equalizer can be adjusted by adjusting the tap factor (TAP). By monitoring the emission dispersion eye diagram closed-loop four-phase TDECQ parameters of the output optical signal, the tap factor (TAP) can be adjusted to obtain a more suitable TAP.
[0104] In some embodiments, as shown in FIG7, the high-speed data electrical signal output by the PAM4 chip / NRZ chip in the host computer / Serdes is transmitted to the digital equalizer 112 of the optical module 200; the input terminal of the digital equalizer 112 is electrically connected to the electrical connector 211 on the circuit board 300 in the optical module 200 to receive the high-speed analog electrical signal from the host computer / Serdes. The electrical connector can be an electrical connection pin or a pin header.
[0105] At this time, the high-speed data signal is a high-speed digital signal. The digital equalizer performs equalization compensation on the high-speed digital signal. The output of the digital equalizer is electrically connected to the digital-to-analog converter (DAC) to transmit the digitally equalized signal to the DAC.
[0106] In some embodiments, as shown in FIG7, the optical module 200 includes a digital-to-analog signal converter (DAC) 113 disposed on the surface of the circuit board 300. The DAC 113 can convert digital electrical signals into analog electrical signals. In some embodiments, the input terminal of the DAC 113 is electrically connected to the output terminal of the digital equalizer 112 to receive the digitally equalized digital electrical signal, which is converted into an analog electrical signal by the DAC 113, and the output terminal of the DAC 113 outputs the analog electrical signal.
[0107] After digital compensation by digital equalizer 112, the quality of the lost electrical signal can be improved. However, when using only digital equalization to compensate for low modulation bandwidth and / or high RF connection loss, the performance will be limited due to the influence of peak-to-average power ratio (PAPR). Therefore, it is necessary to combine digital equalization with analog equalization. The applicant proposes a technical solution that combines digital equalization and analog equalization. After digital equalization is completed, the digital signal is converted into an analog signal by DAC 113 to facilitate subsequent analog equalization.
[0108] In some embodiments, as shown in FIG7, the optical module 200 includes an analog equalizer 310 disposed on the surface of the circuit board 300. The analog equalizer 310 can reduce the amplitude of the low-frequency part of the analog electrical signal. The analog equalizer 310 is a circuit composed of resistors, inductors, capacitors, etc. By adjusting the resistance, inductance, or capacitance values of the circuit, the equalization effect of the analog equalizer can be adjusted.
[0109] In some embodiments, the analog equalizer 310 of the optical module is an active analog equalizer, which can boost the high-frequency portion of the analog electrical signal. The active analog equalizer includes an amplifier, and the equalization effect can be adjusted by controlling the amplifier gain.
[0110] In some embodiments, the input of the analog equalizer 310 in the optical module is electrically connected to the DAC 113, and its output provides an equalized high-speed analog electrical signal.
[0111] Figure 8 shows another electrical connection diagram between the optical module and the host computer according to some embodiments. As shown in Figure 8, the input terminal of the analog equalizer 310 in the optical module 200 is electrically connected to the electrical connector 211 on the circuit board of the optical module to receive high-speed analog electrical signals from the host computer / Serdes. The electrical connector can be an electrical connection pin or a pin header. The host computer / Serdes 100 includes a digital equalizer 112, which performs digital equalization; the host computer / Serdes also includes a DAC 113, which converts the high-speed digital signal into a high-speed analog electrical signal and transmits the high-speed analog electrical signal to the optical module 200.
[0112] Due to the influence of peak-to-average power ratio (PAPR), the equalization performance of digital equalizer 112 is limited. The performance defects of digital equalizer can be compensated by analog equalizer 310 continuing to equalize the digitally equalized electrical signal.
[0113] In some embodiments, the high-speed analog electrical signal output by the analog equalizer 310 is transmitted to the laser driver chip 213 in the optical module 200, and the laser driver chip 213 drives the laser chip to emit an optical signal based on the high-speed analog electrical signal. The analog equalizer 310 can be set in the optical module 200 to output the high-speed analog electrical signal; alternatively, the analog equalizer 310 can be set in the host computer / Serdes to output the high-speed analog electrical signal, and then the high-speed analog electrical signal is transmitted to the optical module 200.
[0114] In some embodiments, as shown in FIG8, the optical module 200 includes a laser driver chip 213, which receives high-speed data signals and provides driving signals to the laser chip based on the high-speed data signals to drive the laser chip or optical modulation chip to emit optical signals.
[0115] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this disclosure, and are not intended to limit them. Although this disclosure has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this disclosure.
Claims
1. An optical module, comprising: The circuit board has an electrical connector on its surface; the electrical connector is connected to a high-speed data signal from a host computer. The optical module also includes an analog equalizer, which is disposed on the surface of the circuit board and its input terminal is electrically connected to the electrical connector. The analog equalizer is used to receive the high-speed analog signal when the high-speed data signal is a high-speed analog signal. The analog equalizer is also used to perform analog equalization on the high-speed analog signal. Alternatively, the optical module may further include a digital equalizer, a digital-to-analog converter, and an analog equalizer. The digital equalizer is disposed on the surface of the circuit board, and its input terminal is electrically connected to the electrical connector. It is used to receive the high-speed digital signal when the high-speed data signal is a high-speed digital signal. The digital equalizer is also used to perform digital equalization on the high-speed digital signal. The digital-to-analog converter is disposed on the surface of the circuit board, and its input terminal is electrically connected to the output terminal of the digital equalizer. It receives the digitally equalized high-speed digital signal and converts the received high-speed digital signal into a high-speed analog signal. The analog equalizer is disposed on the surface of the circuit board, and its input terminal is electrically connected to the output terminal of the digital-to-analog converter. The analog equalizer is used to receive the high-speed analog signal and perform analog equalization on the high-speed analog signal. A laser driver chip is disposed on the surface of the circuit board. Its input terminal is electrically connected to the output terminal of the analog equalizer. It receives the high-speed analog electrical signal after analog equalization and generates a modulated electrical signal. The laser chip or optical modulation chip has its input terminal electrically connected to the output terminal of the laser driver chip, receives the modulation electrical signal, and outputs an optical signal.
2. A host computer for an optical module, comprising: PAM4 chip / NRZ chip, outputs high-speed digital electrical signals; The host computer also includes a digital equalizer and a digital-to-analog converter. The input of the digital equalizer is electrically connected to the PAM4 chip / NRZ chip to receive the high-speed digital signal. The digital equalizer is used to perform digital equalization on the high-speed digital signal. The input of the digital-to-analog converter is electrically connected to the output of the digital equalizer to receive the digitally equalized high-speed digital signal. The digital-to-analog converter is used to convert the received high-speed digital signal into a high-speed analog signal. Alternatively, the host computer may further include a digital equalizer, a digital-to-analog converter, and an analog equalizer. The input of the digital equalizer is electrically connected to the PAM4 chip / NRZ chip to receive the high-speed digital signal, and the digital equalizer is used to perform digital equalization on the high-speed digital signal. The input of the digital-to-analog converter is electrically connected to the output of the digital equalizer to receive the digitally equalized high-speed digital signal, and the digital-to-analog converter is used to convert the received high-speed digital signal into a high-speed analog signal. The input of the analog equalizer is electrically connected to the output of the digital-to-analog converter to receive the high-speed analog signal, and the analog equalizer is used to perform analog equalization on the high-speed analog signal. An electrical connector is electrically connected to the analog equalizer to transmit high-speed analog electrical signals, which have undergone digital and analog equalization, to the optical module.