A direct-current-radio frequency optical engine flexible circuit board based on collinear time division multiplexing

Abstract

The utility model discloses a kind of DC-RF light engine flexible circuit board based on collinear time division multiplexing, it relates to optical device circuit board technical field.The utility model is integrated direct current loop layer and radio frequency loop layer in same flexible circuit board, using ground via, ground hole grid and time division multiplexing etc. Design, realize the effective isolation and high-efficiency transmission of direct current and radio frequency signal, not only avoid the crosstalk and bending damage problem caused by traditional double board scheme, but also significantly reduce material and processing cost, simplify assembly process, improve the integration of light engine, electromagnetic compatibility and reliability, so as to have stronger practicality and industrialization application value while guaranteeing performance.

Description

Technical Field

[0001] This utility model relates to the field of natural language processing technology, and in particular to a flexible circuit board for a DC-RF optical engine based on collinear time-division multiplexing. Background Technology

[0002] In the optical communication industry, the rapid development of technologies such as 5G and data centers has placed higher demands on the performance of optical engines (which are related to the speed, stability, and reliability of optical communication). Market competition has also forced companies to urgently reduce the cost of optical devices. However, traditional flexible circuit board designs for optical engines have many limitations: to prevent crosstalk, separate flexible circuit boards for DC and RF circuits are required, resulting in high material and manufacturing costs; during customer assembly, bending of the flexible circuit board can cause changes in RF performance and electromagnetic radiation in the DC circuit, easily leading to crosstalk; double soldering and forced bending can also damage the circuitry, reducing reliability and yield; moreover, the large number of signal lines makes wiring and processes complex, making it difficult to control costs and hindering miniaturization integration. At the same time, the layout of flexible circuit boards for optical engines faces a prominent contradiction between increased functionality and circuitry and limited space. For example, in backlight detection, traditional multi-channel MPD circuits (such as 4 MPD + 1 GND) occupy a lot of space, while MPD signals are slow-changing analog quantities that do not require real-time accurate acquisition. Existing multiplexing technologies also struggle to balance requirements with cost and performance. Therefore, the shortcomings of traditional solutions in terms of cost control, crosstalk avoidance, space utilization, and line simplification urgently require innovative breakthroughs to adapt to the needs of industry development. Utility Model Content

[0003] The purpose of this invention is to provide a flexible circuit board for a DC-RF optical engine based on collinear time-division multiplexing, so as to improve the above-mentioned technical problems.

[0004] To achieve the above-mentioned objectives, the present invention provides the following technical solutions:

[0005] A flexible circuit board for a DC-RF optical engine based on collinear time-division multiplexing includes, from bottom to top, a shielding layer, a cover film layer, a DC-RF loop layer, a cover film layer, and a shielding layer; the DC-RF loop layer integrates a DC loop layer and an RF loop layer, and isolates the DC loop layer and the RF loop layer through ground vias; and ground vias are provided on both sides of the RF loop layer;

[0006] The DC trace layer includes N DC traces; the RF signal trace layer includes M RF signal traces.

[0007] A row of ground vias is provided between adjacent DC traces of the DC loop layer and between RF signal traces of adjacent RF loop layers.

[0008] The DC loop layer adopts a collinear time-division multiplexing method, including at least one DC trace and one GND line, and is connected to an external MCU through a signal conditioning circuit, and is connected to an external time-division controller through a channel switching execution link;

[0009] The MCU sends pulse signals for the corresponding DC traces during the pulse transmission phase; the time-division controller switches DC traces based on pulse counts during the line switching setup phase; the MCU acquires voltage and converts it to current during the data acquisition phase; and polling enables the use of multiple DC traces.

[0010] This invention integrates a DC loop layer and an RF loop layer on the same flexible circuit board. By employing designs such as ground vias, ground via gates, and time-division multiplexing, it achieves effective isolation and efficient transmission of DC and RF signals. This not only avoids the crosstalk and bending damage problems caused by traditional dual-board solutions, but also significantly reduces material and processing costs, simplifies assembly processes, and improves the integration, electromagnetic compatibility, and reliability of the optical engine. Thus, while ensuring performance, it has stronger practicality and industrial application value.

[0011] Furthermore, the shielding layer is made of a thin film of absorbing material, such as graphene, carbon fiber, ferrite and magnetic iron nanomaterials, to absorb the electromagnetic radiation scattered into the surrounding space by the radio frequency signal traces of the radio frequency circuit layer.

[0012] In the above solution, the absorbing material film can efficiently absorb the electromagnetic radiation scattered by the radio frequency signal traces in the radio frequency loop layer into the surrounding space. On the one hand, it can avoid radio frequency radiation interference with the bias voltage / current transmission of the DC loop and prevent DC signal distortion; on the other hand, it can reduce the electromagnetic interference of the circuit board to the outside world and improve the overall electromagnetic compatibility.

[0013] Furthermore, the DC loop layer and the RF loop layer share a common dielectric layer; the dielectric layer includes a first dielectric layer and a second dielectric layer.

[0014] In the above scheme, by sharing a dielectric layer between the DC loop layer and the RF loop layer, the number of independent dielectric layers can be reduced, significantly reducing the overall thickness and material cost of the optical engine flexible circuit board, and simplifying the design and manufacturing process of the multilayer structure.

[0015] Furthermore, the DC loop layer includes a DC loop ground, a first dielectric layer, and a DC trace layer from bottom to top;

[0016] The DC loop ground and the N DC traces in the DC trace layer form a DC loop, and provide a zero potential reference point for the DC loop, stabilize the potential of the DC loop, and provide a return path for the DC traces to transmit the bias voltages / currents of the optical devices.

[0017] The first dielectric layer provides electrical insulation to prevent short circuits between the DC ground and the DC trace layer.

[0018] In the above scheme, a DC loop is formed by the DC loop ground and the DC trace layer and a zero potential reference point is provided to stabilize the DC loop potential and provide a return path for bias voltage / current transmission, ensuring the stability and accuracy of the bias signal transmission of the optical device. The first dielectric layer provides electrical insulation to avoid short circuit between the DC loop ground and the DC trace layer, improving the safety and reliability of the circuit. Moreover, the integrated structural design reduces external lines, compresses wiring space, and adapts to the needs of miniaturization and multi-channel integration of optical engines, ultimately supporting the technical goals of miniaturization, high reliability and precise control of optical devices.

[0019] Furthermore, a row of ground vias is provided between the accompanying ground via and an adjacent DC trace.

[0020] In the above solution, a row of ground vias is set between two adjacent DC traces and between the ground via and adjacent DC traces. The core is to utilize the characteristic of the ground vias that "multiple holes are continuously arranged to form a low impedance grounding barrier": on the one hand, it can block crosstalk caused by signal coupling between adjacent DC traces and avoid the bias voltage / current transmitted by each DC trace from interfering with each other and causing distortion; on the other hand, it can isolate the influence of stray electromagnetic radiation around the ground via (such as radiation generated by the RF circuit through the ground via) on the DC trace, and prevent the DC signal from being interfered with, which would cause the bias of optical devices (such as lasers) to be unstable. By setting the ground vias according to the trace (extension direction) of the DC trace, the crosstalk risk of the entire DC trace can be covered without increasing the spacing of the DC traces. This is suitable for scenarios where the space of the optical engine flexible circuit board is limited, ensuring the accuracy of DC signal transmission and improving the working reliability of optical devices and the integration of the circuit board.

[0021] Furthermore, the radio frequency (RF) loop layer includes, from bottom to top, an RF loop ground, a second dielectric layer, and an RF signal trace layer; wherein:

[0022] The radio frequency (RF) loop ground is used to form an RF loop with the M RF signal traces in the RF signal trace layer, and to provide a zero potential reference point for the RF signals in the RF loop, so as to transmit the RF signals of the optical device through the RF signal trace layer.

[0023] The second dielectric layer provides electrical insulation to prevent short circuits between the RF loop ground and the RF signal trace layer.

[0024] In the above scheme, the stacked structure of the bottom-up RF loop ground, the second dielectric layer, and the RF signal trace layer can form a complete RF loop with the M-channel RF signal traces and provide a stable zero-potential reference point. This can prevent RF signals from being reflected or distorted due to reference potential fluctuations during transmission, ensuring the integrity and stability of the RF signal transmission of optical devices. The second dielectric layer effectively isolates the RF loop ground and the RF signal trace layer through electrical insulation, preventing short-circuit faults caused by contact between the two, thus strengthening the bottom line for safe circuit operation. It also meets the high-density layout requirements of the M-channel RF signal traces without requiring excessive additional space.

[0025] Furthermore, a row of ground vias is provided between the accompanying ground via and an adjacent RF signal trace.

[0026] In the above scheme, by setting ground vias between adjacent RF signal traces and between ground vias and RF signal traces, the grounding barrier effect of the ground vias can be used to block electromagnetic coupling between adjacent RF signal traces, avoiding mutual interference and distortion of high-frequency RF signals; at the same time, it isolates the influence of stray radiation around the ground vias on the RF traces, ensuring the integrity of RF signal transmission of optical devices.

[0027] Furthermore, the time-sharing controller consists of a shift register / counter and an analog switch controller.

[0028] In the above scheme, the shift register / counter can accurately identify the pulse signal sent by the MCU and complete the counting, providing a clear logical control basis for the switching of multi-channel DC traces and ensuring the orderliness of polling switching; the analog switch controller can quickly execute the path switching of DC traces according to the counting results, ensuring the stability of the line switching establishment phase and avoiding signal interruption or distortion; the two work together to adapt to the co-line time-division multiplexing architecture, which not only reduces the control burden of the MCU, but also ensures the accuracy and efficiency of multi-channel signal acquisition, while simplifying the hardware structure of the controller, which is conducive to integration into the flexible circuit board of the optical engine, further supporting the miniaturization and high reliability design of the circuit board.

[0029] Furthermore, the signal conditioning circuit includes a grounding capacitor C5 and a grounding resistor R5; the non-grounded end of the grounding resistor R5 is connected to the non-grounded end of the grounding capacitor C5, the ADC port and Tout port of the MCU, and the flexible circuit board of the optical engine.

[0030] In the above scheme, R5 and C5 form an RC filter structure, effectively filtering out high-frequency noise and interference in the signals transmitted by the flexible circuit board of the optical engine. This prevents noise from affecting the signal acquisition accuracy of the MCU ADC port, ensuring accurate voltage acquisition data and thus guaranteeing the reliability of subsequent current conversion and optical device operating status judgment. Furthermore, it stabilizes the pulse control signal output from the MCU Tout port, reducing distortion or reflection during signal transmission and providing a stable control signal for line switching under a time-division multiplexing architecture.

[0031] Furthermore, the channel switching execution link includes the same number of links as the DC traces in the DC loop layer; one end of each link is connected to the optical engine flexible circuit board and the time-division controller respectively; the other end of each link is connected to an analog switch; when the analog switch is closed, the GPIO port of the time-division controller and the corresponding backlight detection circuit are turned on.

[0032] The backlight detection circuit includes a laser and a monitoring photodiode; one end of the laser is connected to an analog switch, and the other end is connected to one end of the monitoring photodiode and grounded; the other end of the photodiode serves as the IBIAS port.

[0033] In the above scheme, by making the number of channel switching execution links consistent with the number of DC traces, independent link control is achieved for each DC trace, avoiding cross-interference of signals from multiple channels. Each link connects the optical engine flexible circuit board, the time-division controller and the analog switch. When the analog switch is closed, the GPIO port of the time-division controller is precisely connected to the corresponding backlight detection circuit, which can quickly switch the target detection channel according to the time-division multiplexing requirements, ensuring that each channel works independently and in an orderly manner. Attached Figure Description

[0034] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this utility model and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0035] Figure 1 This is a cross-sectional view of the circuit board in Embodiment 1 of this utility model; wherein, 1, shielding layer; 2, cover film layer; 3, DC-RF loop layer; 33, ground via; 35, ground via gate; 311, DC trace layer; 311-1, DC trace; 312, DC loop ground; 321, RF signal trace layer; 321-1, RF signal trace; 322, RF loop ground; 341, first dielectric layer; 342, second dielectric layer;

[0036] Figure 2This is a schematic diagram of the DC channel required for a conventional optical emitting device in Embodiment 1 of this utility model;

[0037] Figure 3 This is a schematic diagram of the signal conditioning circuit and channel switching execution link in Embodiment 1 of this utility model;

[0038] Figure 4 This is a schematic diagram of the data acquisition cycle in Embodiment 1 of this utility model;

[0039] Figure 5 This is a schematic diagram of the electromagnetic field of the cross-section of the microstrip line in Embodiment 1 of this utility model;

[0040] Figure 6 This is a schematic diagram of the electromagnetic field of the cross-section of the microstrip line after adding a shielding layer and a ground via in Embodiment 1 of this utility model.

[0041] Figure 7 This is the circuit layout of the flexible circuit board for the light engine in Embodiment 2 of this utility model;

[0042] Figure 8 This is the circuit layout of the flexible circuit board for the light engine in Embodiment 2 of this utility model. Detailed Implementation

[0043] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0044] Example 1:

[0045] Please see Figure 1 This embodiment provides a flexible circuit board for a DC-RF optical engine based on collinear time-division multiplexing, comprising, from bottom to top, a shielding layer 1, a cover film layer 2, a DC-RF loop layer 3, a cover film layer 2, and a shielding layer 1; the DC-RF loop layer 3 integrates a DC loop layer and an RF loop layer, and isolates the DC loop layer and the RF loop layer through a ground via 33; the DC loop layer and the RF loop layer share a dielectric layer, and ground vias 33 are provided on both sides of the RF loop layer; the material of the ground vias 33 is copper;

[0046] The DC trace layer 311 includes N DC traces 311-1; the RF signal trace layer 321 includes M RF signal traces 321-1.

[0047] A row of ground hole grids 35 are provided between adjacent DC traces 311-1 of the DC loop layer and between adjacent RF signal traces 321-1 of the RF loop layer, arranged uniformly according to the direction of DC trace 311-1 / RF signal trace 321-1. Figure 1 The white portion in the middle refers to the arrangement of a row of ground vias 35 uniformly arranged in the direction of DC trace 311-1 between two adjacent DC traces, and a row of ground vias 35 uniformly arranged in the direction of RF signal trace 321-1 between two adjacent RF signal traces; the dielectric layer is divided into a first dielectric layer 341 and a second dielectric layer 342.

[0048] In the production of flexible circuit boards, a DC-DC loop layer is provided on both sides of the radio frequency loop layer, and the two DC-DC loop layers have identical structures. Therefore, in... Figure 1 In the DC-RF loop layer 3 of the flexible circuit board, only one DC loop layer and one RF loop layer are shown. To clearly show the structural details, the DC loop layer on the other side of the RF loop layer is omitted.

[0049] like Figure 2 As shown, in traditional optical transmitting devices, when using MCU control channels, the number of DC traces 311-1 corresponds to the number of MCU ADC channels connected. Each ADC channel corresponds to a signal conditioning circuit and link. In this case, the circuit board area needs to be too large to have enough space for the wiring layout. Therefore, this embodiment adopts a collinear time-division multiplexing method to adjust the original 5 lines into a 2-line design, so that the DC circuit and the RF circuit can be used normally on the same circuit board.

[0050] Therefore, the DC loop layer adopts a collinear time-division multiplexing method, including at least one DC trace 311-1 and one GND line, and is externally connected to an MCU through a signal conditioning circuit, and externally connected to a time-division controller through a channel switching execution link;

[0051] The MCU sends the corresponding pulse signal of DC trace 311-1 during the pulse transmission phase; the time-division controller switches DC trace 311-1 according to the pulse count during the line switching establishment phase; the MCU collects voltage and converts current during the data acquisition phase; and multiple DC traces 311-1 are used through polling.

[0052] The time-sharing controller consists of a shift register / counter and an analog switch controller.

[0053] like Figure 3As shown, the signal conditioning circuit includes a grounding capacitor C5 and a grounding resistor R5; the non-grounded end of the grounding resistor R5 is connected to the non-grounded end of the grounding capacitor C5, the ADC port and Tout port of the MCU, and the flexible circuit board of the optical engine.

[0054] like Figure 3 As shown, the channel switching execution link includes the same number of links as the DC traces 311-1 in the DC loop layer; one end of each link is connected to the optical engine flexible circuit board and the time-division controller respectively; the other end of each link is connected to an analog switch; when the analog switch is closed, the GPIO port of the time-division controller and the corresponding backlight detection circuit are turned on.

[0055] The backlight detection circuit includes a laser and a monitoring photodiode; one end of the laser is connected to an analog switch, and the other end is connected to one end of the monitoring photodiode and grounded; the other end of the photodiode serves as the IBIAS port.

[0056] Specifically, the data collection period is defined and divided into three consecutive phases; for example... Figure 4 As shown, the three consecutive stages are pulse transmission stage T1, line switching establishment stage T2, and data acquisition stage T3.

[0057] In this embodiment, the DC trace 311-1 of the flexible circuit board of the light engine is a backlight detection line, and N is set to 4. The four backlight detection lines are respectively designated as MPD1, MPD2, MPD3, and MPD4. Each MPD is connected to the DC ground 312 and serves as a loop.

[0058] During the line switching establishment phase, the signals on each MPD line are in an unstable state when the channel is switched. This is the channel establishment time, and the data is invalid and not used. Therefore, it is necessary to wait for the channel to stabilize, that is, after the line switching establishment phase T2 is completed, before data acquisition and calculation can be performed.

[0059] During the pulse transmission phase, the MCU sends the corresponding pulse signal to the DC trace 311-1 in the flexible circuit board of the light engine, and the pulse count is detected by the analog switch controller.

[0060] During normal use, the MPD (MPulsed Detection) of the emitting optical device is mainly used to monitor whether the laser is emitting light normally. It does not require highly precise real-time acquisition, and since the MPD signal is an analog quantity that changes slowly, it only needs to be acquired within a unit of time. The emitting optical device internally carries an analog switch controller, whose function is to detect and count pulses within a unit of time. For example, if one pulse signal is received within a unit of time, the first MPD detection loop is activated; if two pulse signals are received, the second MPD loop is activated. Similarly, if N pulse signals are received, the Nth MPD loop is activated.

[0061] During the line switching setup phase, DC line 311-1 is switched via analog switch controller based on pulse count and then waits until the line switching setup phase ends.

[0062] During the data acquisition phase, the voltage of DC trace 311-1 on the flexible circuit board of the optical engine is acquired by the MCU and calculated to obtain the current value of the corresponding DC trace 311-1, thereby determining the working state of the laser in the optical device; after the acquisition is completed, the DC trace 311-1 is discharged by the MCU.

[0063] The process involves repeating the pulse transmission phase, the line switching setup phase, and the data acquisition phase until the current acquisition of each DC trace 311-1 is completed. In other words, all DC traces 311-1 are cycled through until the acquisition of all DC traces 311-1 is completed.

[0064] Therefore, this invention employs a collinear time-division multiplexing method, which significantly reduces the number of ADC channels and peripheral signal conditioning circuits in the MCU. It compresses the original solution requiring multiple independent DC traces 311-1 into a combination of a few traces and GND lines, greatly reducing wiring space requirements and avoiding the installation and design difficulties caused by excessively large circuit board areas. Simultaneously, the time-division controller enables switching and polling of multiple DC traces 311-1, ensuring the detection requirements of each channel. This not only reduces MCU resource consumption but also decreases the number of copper traces on the circuit board, improving the integration and reliability of the flexible circuit board. Since the backlight detection signal itself changes slowly, time-division acquisition does not affect detection accuracy or performance, thus achieving the design goals of circuit board miniaturization, low cost, and high efficiency while ensuring performance.

[0065] like Figure 5 As shown, when the RF circuit is working, it generates a magnetic field and radiates to the left and right sides. The AC spurious signals in the RF circuit will be inserted into the DC circuit. The DC circuit will then be superimposed on the RF circuit through the drive bias circuit to form crosstalk, which will cause the bias voltage and current to be unstable. At the same time, it will also cause crosstalk between channels and signal energy leakage, thereby reducing the RF performance and electromagnetic compatibility of optical devices.

[0066] Therefore, as Figure 6As shown, this embodiment has shielding layers 1 on the upper and lower surfaces, using absorbing material films such as graphene, carbon fiber, ferrite, and magnetic iron nanomaterials to absorb the electromagnetic radiation scattered by the RF signal traces 321-1 of the RF loop layer into the surrounding space. Furthermore, the ground vias 33 placed on both sides of the RF loop layer can absorb the radiated magnetic field of the RF signal back to the RF reference ground, similar to the function of an electromagnetic shielding grid, effectively preventing the RF signal from radiating into the surrounding space and reducing crosstalk to adjacent channels and DC loops. In actual use, the material of the shielding layer 1 is determined according to the transmission rate. The shielding layer 1 absorbs the electromagnetic radiation from the RF loop into the surrounding space. When the RF signal traces 321-1 are microstrip line structures, simulations are performed on a traditional optical engine flexible circuit board. According to the simulation results, the electromagnetic radiation spacing between different RF signal traces 321-1 is three times the line width. That is, to reduce crosstalk between channels, the safe distance between different RF signal traces 321-1 is at least three times the width of the RF signal traces 321-1.

[0067] However, in the application of optical devices, due to the space limitations of flexible circuit boards, it is usually impossible to meet the requirement that the safe distance between different RF signal traces 321-1 is at least three times the width of the RF signal trace 321-1. Therefore, the method of adding a shielding layer 1 is adopted. Experiments were conducted on the flexible circuit board of the optical engine of this utility model. According to the experimental results, it can be seen that a safe distance of 1 times the line width is sufficient to meet the requirement of reducing crosstalk between channels. Thus, the spacing between the ground aperture gates 35 in the same layer of the DC loop layer or the RF loop is less than one-tenth of the laser wavelength emitted by the laser emitter in the optical device, allowing the circuit board to work normally.

[0068] The DC circuit layer and the radio frequency circuit layer share a common dielectric layer; the dielectric layer includes a first dielectric layer 341 and a second dielectric layer 342.

[0069] The DC loop layer includes a DC loop ground 312, a first dielectric layer 341, and a DC trace layer 311 from bottom to top; the DC loop ground 312 and the N DC traces 311-1 in the DC trace layer 311 form a DC loop and provide a zero potential reference point for the DC loop, stabilize the potential of the DC loop, and provide a return path for the DC traces 311-1 to transmit the bias voltages / currents of the optical devices;

[0070] The first dielectric layer 341 is used to provide electrical insulation to prevent short circuits between the DC circuit ground 312 and the DC trace layer 311.

[0071] The DC trace 311-1 is a temperature control circuit or a backlight detection circuit; a row of ground vias 35 is provided between two adjacent DC traces 311-1, and a row of ground vias 35 is provided between the accompanying ground via 33 and an adjacent DC trace 311-1.

[0072] The radio frequency (RF) loop layer includes, from bottom to top, an RF loop ground 322, a second dielectric layer 342, and an RF signal trace layer 321; wherein:

[0073] RF loop ground 322 is used to form an RF loop with M RF signal traces 321-1 in RF signal trace layer 321, and to provide a zero potential reference point for RF signals in the RF loop, and to transmit RF signals of optical devices through RF signal trace layer 321;

[0074] The second dielectric layer 342 is used to provide electrical insulation to prevent short circuits between the RF loop ground 322 and the RF signal trace layer 321.

[0075] A row of ground vias 35 is provided between two adjacent RF signal traces 321-1, and a row of ground vias 35 is provided between a ground via 33 and an adjacent RF signal trace 321-1.

[0076] In the RF loop layer, according to the signal transmission control command, the RF signal generated by the signal source is transmitted to the load through any RF signal trace 321-1, and then returned through the RF loop ground 322 after passing through the load.

[0077] The first dielectric layer 341 and the second dielectric layer 342 are located in the same dielectric layer and are isolated from each other by a ground via 33. The DC loop ground 312 and the RF loop ground 322 are located in the same routing layer, and the DC routing layer 311 and the RF signal routing layer 321 are located in the same routing layer, all separated by ground vias 33. Furthermore, a row of ground vias 35 is provided between the DC loop ground 312 and the adjacent ground vias 33.

[0078] When the spacing between grounding structures is greater than one-tenth of the wavelength, it not only fails to effectively block stray electromagnetic radiation but may also become a new source of interference. Therefore, in each row of ground vias 35, the spacing between two adjacent ground vias 35 is less than one-tenth of the laser wavelength in the optical device. This can completely absorb the electromagnetic coupling energy between adjacent traces (such as RF signal traces 321-1 and DC traces 311-1), avoiding distortion of high-frequency RF signals or DC bias signals related to lasers due to crosstalk. At the same time, this small-pitch setting does not require increasing the physical spacing of the traces to achieve isolation. It can accommodate multi-channel trace layouts within the limited space of the optical engine flexible circuit board, ensuring the integrity of RF signal transmission and the stability of DC signals, while also meeting the needs of miniaturization and high-density integration of optical devices.

[0079] To effectively isolate the influence of electromagnetic radiation on the circuit board and ensure the stable operation of the DC circuit, this embodiment provides a ground via 33 on each side of the RF circuit layer to further absorb the radiated magnetic field of the RF signal back to the RF reference ground, similar to the function of an electromagnetic shielding barrier, as shown in Figure 6. This effectively prevents the RF signal from radiating into the surrounding space and reduces crosstalk to adjacent channels and the DC circuit.

[0080] Among them, the ground via 33 is placed on one side of the DC-RF loop layer 3 to provide a low-impedance return path for the RF signal and stabilize the transmission of the RF signal; the ground via 33 is placed inside the DC-RF loop layer 3 to provide a low-impedance return path for the RF signal, stabilize the transmission of the RF signal, and isolate the DC loop layer and the RF loop layer.

[0081] In summary, this embodiment, by integrating the DC-DC loop layer and the RF loop layer within the same flexible circuit board, and in conjunction with the structural design of shielding layer 1, absorbing material, ground via 33, and ground via 35, not only solves the electromagnetic crosstalk problem caused by the separation of the DC-DC board and the RF board in traditional solutions, but also demonstrates significant beneficial effects in the following aspects: In terms of circuit board structure, it achieves a high degree of integration of DC and RF, avoiding the stacking of multiple boards and making the wiring more compact and reasonable; in terms of circuit board size, by utilizing collinear time-division multiplexing and optimized electromagnetic shielding design, it significantly reduces the number of traces and safety spacing requirements, thereby reducing the overall size of the flexible circuit board and meeting the miniaturization requirements of optical devices; in terms of cost, single-board integration replaces dual-board fabrication, reducing material and processing costs, while simplifying soldering and assembly processes and reducing failure rates, thus achieving a low-cost, high-reliability circuit board solution.

[0082] Example 2:

[0083] like Figure 7 and Figure 8 As shown, the circuit layout of the flexible circuit board for the light engine is illustrated. The black lines within the red boxes on both sides are DC traces 311-1, while the remaining black lines are RF signal traces 321-1. Dense black dots (ground vias 35, ground vias 33, etc.) are distributed between the lines. The RF signal is transmitted upwards through RF signal traces 321-1, and also through... Figure 8 The large copper area flows downwards, forming a complete loop. These traces and via structures demonstrate the compact integration design of the DC loop layer and the RF loop layer on the same flexible circuit board. Isolation between different traces is achieved through structures such as vias to suppress electromagnetic crosstalk, showcasing the compactness and integration of the circuit board wiring, and providing a hardware foundation for the compatible transmission of DC and RF signals.

[0084] It should be noted that the specific methods by which each module performs operations in the system described in the above embodiments have been described in detail in the embodiments related to the method, and will not be elaborated here.

[0085] The above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

[0086] The above description is merely a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this utility model should be included within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the scope of the claims.

Claims

1. A flexible circuit board for a DC-RF optical engine based on collinear time-division multiplexing, comprising, from bottom to top, a shielding layer (1), a cover film layer (2), a DC-RF loop layer (3), a cover film layer (2), and a shielding layer (1); characterized in that, The DC-RF loop layer (3) integrates the DC loop layer and the RF loop layer, and isolates the DC loop layer and the RF loop layer through a ground via (33); and a ground via (33) is provided on both sides of the RF loop layer. The DC trace layer (311) includes N DC traces (311-1); the RF signal trace layer (321) includes M RF signal traces (321-1). A row of ground vias (35) is provided between adjacent DC traces (311-1) of the DC loop layer and between radio frequency signal traces (321-1) of adjacent radio frequency loop layers. The DC loop layer adopts a collinear time-division multiplexing method, including at least one DC trace (311-1) and one GND line, and is connected to an external MCU through a signal conditioning circuit, and is connected to an external time-division controller through a channel switching execution link; The MCU sends pulse signals to the corresponding DC trace (311-1) during the pulse transmission phase; the time-division controller switches the DC trace (311-1) according to the pulse count during the line switching establishment phase; the MCU collects voltage and converts current during the data acquisition phase; and multiple DC traces (311-1) are used through polling.

2. The flexible circuit board for a DC-RF optical engine based on collinear time-division multiplexing according to claim 1, characterized in that, The shielding layer (1) is made of a thin film of absorbing material, which is composed of graphene, carbon fiber, ferrite and magnetic iron nanomaterials, to absorb the electromagnetic radiation scattered into the surrounding space by the radio frequency signal trace (321-1) of the radio frequency circuit layer.

3. The flexible circuit board for a DC-RF optical engine based on collinear time-division multiplexing according to claim 1, characterized in that, The DC loop layer and the RF loop layer share a common dielectric layer; the dielectric layer includes a first dielectric layer (341) and a second dielectric layer (342).

4. A flexible circuit board for a DC-RF optical engine based on collinear time-division multiplexing according to claim 3, characterized in that, The DC loop layer includes a DC loop ground (312), a first dielectric layer (341), and a DC trace layer (311) from bottom to top. The DC loop ground (312) and the N DC traces (311-1) in the DC trace layer (311) form a DC loop, and provide a zero potential reference point for the DC loop, stabilize the potential of the DC loop, and provide a return path for the DC traces (311-1) to transmit the bias voltages / currents of the optical devices. The first dielectric layer (341) is used to provide electrical insulation to prevent short circuits between the DC circuit ground (312) and the DC trace layer (311).

5. A flexible circuit board for a DC-RF optical engine based on collinear time-division multiplexing according to claim 4, characterized in that, A row of ground vias (35) is provided between the ground via (33) and the adjacent DC line (311-1).

6. A flexible circuit board for a DC-RF optical engine based on collinear time-division multiplexing according to claim 3, characterized in that, The radio frequency (RF) loop layer includes, from bottom to top, an RF loop ground (322), a second dielectric layer (342), and an RF signal trace layer (321); wherein: The radio frequency loop ground (322) is used to form a radio frequency loop with the M radio frequency signal traces (321-1) in the radio frequency signal trace layer (321) and to provide a zero potential reference point for the radio frequency signal in the radio frequency loop. The radio frequency signal of the optical device is transmitted through the radio frequency signal trace layer (321). The second dielectric layer (342) provides electrical insulation to prevent short circuits between the RF loop ground (322) and the RF signal trace layer (321).

7. A flexible circuit board for a DC-RF optical engine based on collinear time-division multiplexing according to claim 6, characterized in that, A row of ground vias (35) is provided between the ground via (33) and the adjacent radio frequency signal trace (321-1).

8. A flexible circuit board for a DC-RF optical engine based on collinear time-division multiplexing according to claim 1, characterized in that, The time-sharing controller consists of a shift register / counter and an analog switch controller.

9. A flexible circuit board for a DC-RF optical engine based on collinear time-division multiplexing according to claim 1, characterized in that, The signal conditioning circuit includes a grounding capacitor C5 and a grounding resistor R5; the non-grounded end of the grounding resistor R5 is connected to the non-grounded end of the grounding capacitor C5, the ADC port and Tout port of the MCU, and the flexible circuit board of the optical engine.

10. A flexible circuit board for a DC-RF optical engine based on collinear time-division multiplexing according to claim 1, characterized in that, The channel switching execution link includes the same number of links as the DC traces (311-1) in the DC loop layer; one end of each link is connected to the optical engine flexible circuit board and the time-division controller respectively; the other end of each link is connected to an analog switch; when the analog switch is closed, the GPIO port of the time-division controller and the corresponding backlight detection circuit are turned on; The backlight detection circuit includes a laser and a monitoring photodiode; one end of the laser is connected to an analog switch, and the other end is connected to one end of the monitoring photodiode and grounded; the other end of the photodiode serves as the IBIAS port.

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