Optical communication testing device

Abstract

The invention discloses an optical communication testing device, and belongs to the technical field of power electronics, and the device comprises a photoelectric conversion unit which is used for converting an optical signal into an electric signal; a low-pass filter in a distributed parameter form is adopted, is connected with the photoelectric conversion unit and is used for filtering the electric signal to obtain a target filtering signal; and the data conversion unit is connected with the low-pass filter and is used for generating an eye pattern corresponding to the target filtering signal. In the device, a low-pass filter in a lumped form is converted into a low-pass filter in a distributed parameter form, and the low-pass filter in the form does not consider various elements in a circuit as a whole, but considers the distribution characteristics of parameters of the various elements in the circuit, so that the low-pass filter in the form has the advantages that the low-pass filter in the form can be converted into a low-pass filter in a distributed parameter form; the low-pass filter of the type can better suppress high-frequency signals outside the bandwidth, so that the eye pattern presentation effect of the optical communication testing device can be further improved.

Description

Technical Field

[0001] The invention relates to the technical field of power electronics, and in particular to an optical communication testing device. Background Art

[0002] Optical communication testing refers to the process of testing the characteristics of optical fiber communication systems. Through optical communication testing, various performance parameters in optical fiber communication systems can be qualitatively and quantitatively analyzed. Therefore, optical communication testing is crucial to ensure the safe and stable operation of optical fiber communication systems.

[0003] When conducting optical communication tests, in order to obtain eye diagrams at different rates, it is usually necessary to integrate low-pass filters of different bandwidths in the optical communication test device to filter the test signal before performing data processing. In the prior art, the low-pass filter is usually set to a lumped form. However, this form of low-pass filter has a low adaptation frequency band and a low bandwidth, and there is a phenomenon that the eye diagram cannot be opened, resulting in a poor presentation of the eye diagram. In addition, when the power frequency in the test circuit is high, the parasitic parameters in the test circuit (such as the parasitic inductance generated by the capacitor pin) cannot be ignored, which causes the high-frequency suppression effect of the low-pass filter to deteriorate, further reducing the presentation of the eye diagram. At present, there is no more effective solution to this technical problem.

[0004] It can be seen that how to improve the eye diagram presentation effect when performing optical communication testing on an optical fiber communication system is a technical problem that needs to be solved urgently by those skilled in the art. Summary of the invention

[0005] In view of this, the purpose of the present invention is to provide an optical communication test device to solve the technical problem in the prior art that the eye diagram presentation effect is poor when performing optical communication testing on an optical fiber communication system. The specific scheme is as follows:

[0006] In order to solve the above technical problems, the present invention provides an optical communication test device, comprising:

[0007] A photoelectric conversion unit, used for converting an optical signal into an electrical signal;

[0008] A low-pass filter in the form of distributed parameters is connected to the photoelectric conversion unit and is used to filter the electrical signal to obtain a target filtered signal;

[0009] A data conversion unit is connected to the low-pass filter and is used to generate an eye diagram corresponding to the target filtered signal.

[0010] Preferably, the low-pass filter comprises: N equivalent inductors, N-1 equivalent capacitors and N-1 equivalent resistors, where N≥2;

[0011] Wherein, N equivalent inductors are connected in series in sequence, the common ends of the N equivalent inductors are connected to the first ends of N-1 equivalent capacitors in one-to-one correspondence, the second ends of the N-1 equivalent capacitors are connected to the first ends of N-1 equivalent resistors in one-to-one correspondence, and the second ends of the N-1 equivalent resistors are all grounded;

[0012] Correspondingly, two ends of the line of the N equivalent inductors connected in series are respectively the input end and the output end of the low-pass filter.

[0013] Preferably, the various elements in the low-pass filter are symmetrically structured with respect to the center point of the target connecting line, and the setting parameters of the two symmetrical elements are the same; the elements include: the equivalent inductance, the equivalent capacitance and the equivalent resistance; the target connecting line is: a connecting line connecting N equivalent inductors in series.

[0014] Preferably, the order of the low-pass filter is positively correlated with the high-frequency suppression effect of the low-pass filter.

[0015] Preferably, the low-pass filter is connected to the photoelectric conversion unit in the form of a microstrip line through a first connector, and the microstrip line is also connected to the data conversion unit through a second connector.

[0016] Preferably, the microstrip line, the first connector and the second connector are all arranged on a PCB board.

[0017] Preferably, the setting parameters of the first connector, the second connector and the PCB board are all set according to the test frequency band of the signal to be tested.

[0018] Preferably, if the operating frequency of the low-pass filter is lower than a preset threshold, the PCB board is a Rogers board; if the operating frequency of the low-pass filter is higher than the preset threshold, the PCB board is a high-speed board.

[0019] The microstrip line includes: a first impedance matching line, a second impedance matching line, a high impedance line, M groups of equivalent resistors and patches connected together; M≥1; the first impedance matching line and the second impedance matching line are designed according to the structure of the PCB board;

[0020] The two ends of the high impedance line are respectively connected to the first impedance matching line and the second impedance matching line, and the high impedance line is connected to M groups of equivalent resistors and patches connected together.

[0021] Preferably, the patch is fan-shaped or rectangular.

[0022] Beneficial effect: It can be seen that in the optical communication test device provided by the present invention, a photoelectric conversion unit, a low-pass filter in the form of distributed parameters and a data conversion unit are provided; after the photoelectric conversion unit converts the optical signal into an electrical signal, the low-pass filter will filter the electrical signal to obtain a target filtered signal; then, the data conversion unit generates an eye diagram corresponding to the target filtered signal. Compared with the prior art, in the present invention, since the lumped low-pass filter is transformed into a distributed parameter low-pass filter, this type of low-pass filter does not consider all components in the circuit as a whole, but considers the distribution characteristics of the parameters of various components in the circuit. Therefore, this type of low-pass filter will better suppress high-frequency signals outside the bandwidth, which can further improve the eye diagram presentation effect of the optical communication test device. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0024] Figure 1 A structural diagram of an optical communication test device provided by an embodiment of the present invention;

[0025] Figure 2 A schematic diagram of the principle of a low-pass filter provided by an embodiment of the present invention;

[0026] Figure 3 A structural diagram of another optical communication test device provided by an embodiment of the present invention;

[0027] Figure 4 A structural diagram of another optical communication test device provided by an embodiment of the present invention;

[0028] Figure 5 A schematic diagram of setting a low-pass filter in an optical communication test device to a 6.25G filter;

[0029] Figure 6 This is a schematic diagram of setting the low-pass filter in the optical communication test device to a 10G filter.

[0030] Figure 7 A structural diagram of a microstrip line provided by an embodiment of the present invention;

[0031] Figure 8 This is a schematic diagram of the return loss of the transmission signal when the low-pass filter in the optical communication test device is set to a 6.25G filter;

[0032] Fig. 9 This is a schematic diagram of the group delay of the transmission signal when the low-pass filter in the optical communication test device is set to a 6.25G filter;

[0033] Fig.10 This is a schematic diagram of the return loss of the transmission signal when the low-pass filter in the optical communication test device is set to a 10G filter;

[0034] Fig.11 This is a schematic diagram of the group delay of the transmission signal when the low-pass filter in the optical communication test device is set to a 10G filter. DETAILED DESCRIPTION

[0035] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0036] See also Figure 1 , Figure 1 A structural diagram of an optical communication test device provided by an embodiment of the present invention, the device comprising:

[0037] A photoelectric conversion unit 11, used to convert an optical signal into an electrical signal;

[0038] A low-pass filter 12 in the form of distributed parameters is connected to the photoelectric conversion unit 11 and is used to filter the electrical signal to obtain a target filtered signal;

[0039] The data conversion unit 13 is connected to the low-pass filter 12 and is used to generate an eye diagram corresponding to the target filtered signal.

[0040] In this embodiment, an optical communication test device is provided. By using the optical communication test device to perform optical communication tests on an optical fiber communication system, the eye diagram presentation effect of the optical communication test device can be significantly improved.

[0041] The optical communication test device is provided with an optoelectronic conversion unit 11, a low-pass filter 12 in the form of distributed parameters, and a data conversion unit 13. After the optoelectronic conversion unit 11 converts the optical signal into an electrical signal, the low-pass filter 12 filters the electrical signal to obtain a target filtered signal. After the low-pass filter 12 filters the electrical signal to obtain a target filtered signal, the data conversion unit 13 generates an eye diagram corresponding to the target filtered signal.

[0042] If the optical fiber communication system is a high-frequency circuit, since the parasitic parameters in the high-frequency circuit (such as the parasitic inductance generated by the capacitor pins) cannot be ignored and even play a dominant role, based on this practical factor, in this application, the low-pass filter 12 in the optical communication test device is transformed from a lumped form to a distributed parameter form. This form of low-pass filter 12 is different from the traditional lumped form. It fully considers the distribution characteristics of various component parameters in the circuit to realize the filtering function, so that it can adapt to the application requirements of high-frequency circuits in different frequency bands.

[0043] A large amount of experimental data shows that the optical communication test device provided in the present application can adapt to eye diagram tests of different rates of 10Gbauds and above, has high bandwidth and good group delay indicators, and can make the eye diagram generated by the data conversion unit 13 have better effect.

[0044] It can be seen that in the optical communication test device provided in this embodiment, a photoelectric conversion unit, a low-pass filter in the form of distributed parameters and a data conversion unit are provided; after the photoelectric conversion unit converts the optical signal into an electrical signal, the low-pass filter will filter the electrical signal to obtain a target filtered signal; then, the data conversion unit generates an eye diagram corresponding to the target filtered signal. Compared with the prior art, in this embodiment, since the lumped low-pass filter is transformed into a distributed parameter low-pass filter, this type of low-pass filter does not consider the various components in the circuit as a whole, but considers the distribution characteristics of the parameters of the various components in the circuit. Therefore, this type of low-pass filter will better suppress high-frequency signals outside the bandwidth, which can further improve the eye diagram presentation effect of the optical communication test device.

[0045] Based on the above embodiments, this embodiment further illustrates and optimizes the technical solution. Figure 2 , Figure 2 A schematic diagram of the principle of a low-pass filter provided by an embodiment of the present invention. As a preferred implementation, the low-pass filter 12 includes: N equivalent inductors L, N-1 equivalent capacitors C and N-1 equivalent resistors R, N≥2;

[0046] Wherein, N equivalent inductors L are connected in series in sequence, the common ends of the N equivalent inductors L are connected to the first ends of N-1 equivalent capacitors C in one-to-one correspondence, the second ends of the N-1 equivalent capacitors C are connected to the first ends of N-1 equivalent resistors R in one-to-one correspondence, and the second ends of the N-1 equivalent resistors R are all grounded;

[0047] Correspondingly, two ends of the line of the N equivalent inductors L connected in series are respectively the input end and the output end of the low-pass filter.

[0048] In this embodiment, the equivalent circuit diagram of the low-pass filter is specifically described. The use of the equivalent circuit diagram of the low-pass filter can simplify the low-pass filter in a complex distributed parameter form into a form that is easier for designers to understand and analyze, so that designers can more accurately and quickly evaluate the performance of the low-pass filter.

[0049] In addition, the equivalent circuit diagram of the low-pass filter can also be used in related simulation software, so that before the low-pass filter is actually manufactured, the equivalent circuit diagram can be used to predict and verify the working performance of the low-pass filter, which helps to discover potential problems in the design stage of the low-pass filter and further improve the production efficiency of the low-pass filter.

[0050] As a preferred embodiment, the various elements in the low-pass filter 12 are symmetrically structured with respect to the center point of the target connecting line, and the setting parameters of the two symmetrical elements are the same; the elements include: equivalent inductance, equivalent capacitance and equivalent resistance; the target connecting line is: a connecting line that connects N equivalent inductors in series.

[0051] In this embodiment, each element in the low-pass filter is symmetrically structured with respect to the center point of the target connection line, and the setting parameters of the two symmetrical elements are the same. Figure 2 , assuming Figure 2 The dotted box 1 is symmetrical with the dotted box 2, so the setting parameters of the equivalent inductance, equivalent capacitance and equivalent resistance in the dotted box 1 are equal to the setting parameters of the equivalent inductance, equivalent capacitance and equivalent resistance in the dotted box 2. That is, if the setting parameters of the equivalent inductance in the dotted box 1 are 1.0nH, the setting parameters of the equivalent capacitance are 1.0pF, and the setting parameters of the equivalent resistance are 50Ohm, then the setting parameters of the equivalent inductance in the dotted box 2 are 1.0nH, the setting parameters of the equivalent capacitance are 1.0pF, and the setting parameters of the equivalent resistance are 50Ohm.

[0052] Of course, in practical applications, the setting parameters of the equivalent inductance, equivalent capacitance and equivalent resistance in the low-pass filter can be adaptively adjusted according to different actual conditions to adapt to different application scenarios.

[0053] When the various components in the low-pass filter are arranged in a symmetrical structure, not only the stability of the circuit structure can be enhanced, but also the filtering effect of the low-pass filter can be improved, and the loss and electromagnetic interference can be reduced.

[0054] In addition, the order of the low-pass filter is positively correlated with the high-frequency suppression effect of the low-pass filter. That is, if the order of the low-pass filter is higher, the low-pass filter will have a better high-frequency suppression effect outside the bandwidth. If the order of the low-pass filter is lower, the low-pass filter will have a relatively poor high-frequency suppression effect outside the bandwidth. Among them, the order of the low-pass filter is equal to the sum of the number of equivalent capacitors and equivalent inductors in the low-pass filter.

[0055] Based on the above embodiments, this embodiment further illustrates and optimizes the technical solution. Figure 3 , Figure 3 As a preferred embodiment, the low-pass filter 12 is connected to the photoelectric conversion unit 11 through the first connector 01 in the form of a microstrip line, and the microstrip line is also connected to the data conversion unit 13 through the second connector 02.

[0056] In practical applications, the distributed parameter low-pass filter 12 is usually presented in the form of a microstrip line. By modifying the length, terminal structure (such as open circuit or short circuit), cross section and other parameters of the microstrip line, the microstrip line can present different impedances, thereby achieving the purpose of filtering signals of different bandwidths.

[0057] The low-pass filter 12 (microstrip line) is usually connected to the photoelectric conversion unit 11 and the data conversion unit 13 through a connector. That is, the low-pass filter 12 (microstrip line) is connected to the photoelectric conversion unit 11 through the first connector 01, and the low-pass filter 12 (microstrip line) is connected to the photoelectric conversion unit 11 through the second connector 02.

[0058] See also Figure 4 , Figure 4 This is a structural diagram of another optical communication test device provided by an embodiment of the present invention. As a preferred implementation, the microstrip line 03 , the first connector 01 and the second connector 0202 are all arranged on the PCB board 04 .

[0059] In practical applications, the microstrip line 03, the first connector 01 and the second connector 02 are all arranged on a PCB (Printed Circuit Board) board 04, that is, the PCB board 04 is used to carry the microstrip line 03, the first connector 01 and the second connector 02. Obviously, under this arrangement, it is more convenient to mass produce the optical communication test device.

[0060] Furthermore, the setting parameters of the first connector 01, the second connector 02 and the PCB board 04 are all set according to the test frequency band of the signal to be tested. That is, the setting parameters of the first connector 01, the second connector 02 and the PCB board 04 need to be adjusted according to the test frequency band of the signal to be tested.

[0061] For example, if the optical communication test device needs to test a signal to be tested within 10G, the first connector 01 and the second connector 02 need to be set as 2.92mm connectors. If the optical communication test device needs to test a signal to be tested above 10G, the first connector 01 and the second connector 02 need to be set as GP30 connectors.

[0062] See also Figure 5 and Figure 6 , Figure 5 This is a schematic diagram of setting the low-pass filter in the optical communication test device to a 6.25G filter. Figure 6 This is a schematic diagram of setting the low-pass filter in the optical communication test device to a 10G filter. When the low-pass filter in the optical communication test device is set to different frequency bands, the low-pass filter will have different sizes and dimensions.

[0063] Specifically, if the operating frequency of the low-pass filter is lower than the preset threshold, the PCB board is a Rogers board; if the operating frequency of the low-pass filter is higher than the preset threshold, the PCB board is a high-speed board.

[0064] In this embodiment, the preset threshold value can be set to 10G. If the operating frequency of the low-pass filter is lower than 10G, the PCB board can be selected as a Rogers board. If the operating frequency of the low-pass filter is higher than 10G, the PCB board can be selected as a high-speed board.

[0065] Since the cost of the Rogers board is relatively lower than that of the high-speed board, under this setting, a more suitable board can be selected to carry the first connector 01, the second connector 02 and the microstrip line 03 (low-pass filter 12) in different application scenarios, which can further reduce the design cost of the optical communication test device.

[0066] See also Figure 7 , Figure 7 A structural diagram of a microstrip line provided by an embodiment of the present invention. As a preferred implementation, the microstrip line 03 includes: a high impedance line 303, a first impedance matching line 301, a second impedance matching line 302, M groups of equivalent resistors 305 and patches 304 connected together; M≥1; the first impedance matching line 301 and the second impedance matching line 302 are designed according to the structure of the PCB board 04;

[0067] The two ends of the high impedance line 303 are connected to the first impedance matching line 301 and the second impedance matching line 302 respectively, and the high impedance line 303 is connected to M groups of equivalent resistors 305 and patches 304 connected together.

[0068] In this embodiment, the microstrip line 03 is specifically described. That is, the microstrip line 03 is mainly composed of a high impedance line 303, a first impedance matching line 301, a second impedance matching line 302, an equivalent resistor 305 and a patch 304. Among them, the first impedance matching line 301 and the second impedance matching line 302 are used to optimize the line width and connector of the microstrip line 03; the high impedance line 303 is equivalent to the equivalent inductance in the low-pass filter, which is used to simulate the inductance in the distributed parameter circuit; the equivalent resistor 305 is used to connect the first connector 01 and the second connector 02, and plays a role in absorbing energy in the circuit; the patch 304 is equivalent to the equivalent capacitor in the low-pass filter, which is used to simulate the capacitor in the distributed parameter circuit.

[0069] In practical applications, in order to improve the filtering effect of the low-pass filter, Figure 7 The structure shown is arranged in a bilaterally symmetrical form. The sizes of the components in the symmetrical part are kept consistent, and the resistance value of the equivalent resistor 305 is also kept consistent.

[0070] In addition, it should be noted that the first impedance matching line 301 and the second impedance matching line 302 are designed for the structure of the PCB board 04. Specifically, if the first connector 01 and the second connector 02 on the PCB board 04 are the same, the first impedance matching line 301 and the second impedance matching line 302 are completely consistent and have a symmetrical structure. If the first connector 01 and the second connector 02 on the PCB board 04 are different, the first impedance matching line 301 needs to be locally optimized at the part close to the first connector 01, and similarly, the second impedance matching line 302 also needs to be locally optimized at the part close to the second connector 02, and the structures of the first impedance matching line 301 and the second impedance matching line 302 will be slightly different.

[0071] As a preferred implementation, the patch 304 is fan-shaped or rectangular.

[0072] Specifically, in practical applications, the patch 304 can be set in a fan-shaped or rectangular form. Because this form of patch 304 has the advantages of simple structure and easy production, when the patch 304 is set in a fan-shaped or rectangular form, the cost and production difficulty of the microstrip line 03 can be further reduced.

[0073] See also Figures 8 to 11 , Figure 8This is a schematic diagram of the return loss of the transmission signal when the low-pass filter in the optical communication test device is set to a 6.25G filter. Fig. 9 This is a schematic diagram of the group delay of the transmission signal when the low-pass filter in the optical communication test device is set to a 6.25G filter. Fig.10 This is a schematic diagram of the return loss of the transmission signal when the low-pass filter in the optical communication test device is set to a 10G filter. Fig.11 This is a schematic diagram of the group delay of the transmission signal when the low-pass filter in the optical communication test device is set to a 10G filter.

[0074] exist Figure 8 and Fig.10 In the figure, the horizontal axis represents the frequency of the transmission signal in Ghz, and the vertical axis represents the S11 parameter in dB. The smaller the value of the S11 parameter, the less signal the system reflects, which means that the match between the input port and the signal source is better, and more energy in the signal source can be transmitted into the system rather than reflected out. Normally, it is hoped that the S11 parameter is less than -10dB in the required frequency band. If the S11 parameter is less than -20dB, this means that the system reflects very few signals, and most of the signals can be effectively transmitted to the inside of the system. Since the 6.25G filter requires its return loss to be less than -10dB, the optical communication test device provided in this application can just meet the actual use requirements.

[0075] exist Fig. 9 and Fig.11 In the figure, the horizontal axis represents the frequency of the transmission signal in Ghz, and the vertical axis represents the group delay in ps. The group delay can indicate the time required for the transmission signal to pass through a system. The flatter the group delay, the smaller the relative delay change between different frequency components when the signal passes through the system, which means that the waveform and phase relationship of the signal are maintained during the transmission process, which can avoid the distortion of the transmission signal. Normally, the group delay fluctuation of 6.25G filters and 10G filters is required to be less than 50ps, and the optical communication test device provided in this application can just meet this test requirement.

[0076] In summary, the optical communication test device provided in the present application can achieve a smaller return loss of the transmission signal and a better group delay, thereby further improving the presentation effect of the eye diagram when performing optical communication testing on the optical fiber communication system.

[0077] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments, and the same or similar parts between the embodiments can be referred to each other. Finally, it should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that there is any such actual relationship or order between these entities or operations. Moreover, the term "include", "comprise" or any other variant thereof is intended to cover non-exclusive inclusion, so that the process, method, article or equipment including a series of elements not only includes those elements, but also includes other elements that are not clearly listed, or also includes elements inherent to such process, method, article or equipment. In the absence of more restrictions, the elements limited by the sentence "including one..." do not exclude the existence of other identical elements in the process, method, article or equipment including the elements.

[0078] The optical communication test device provided by the present invention is introduced in detail above. The principle and implementation mode of the present invention are explained in this article by using specific examples. The description of the above embodiments is only used to help understand the method of the present invention and its core idea. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation mode and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. An optical communication test device, characterized in that: include: A photoelectric conversion unit, used for converting an optical signal into an electrical signal; A low-pass filter in the form of distributed parameters is connected to the photoelectric conversion unit and is used to filter the electrical signal to obtain a target filtered signal; A data conversion unit is connected to the low-pass filter and is used to generate an eye diagram corresponding to the target filtered signal.

2. An optical communication test device according to claim 1, characterized in that: The low-pass filter includes: N equivalent inductors, N-1 equivalent capacitors and N-1 equivalent resistors, where N≥2; Wherein, N equivalent inductors are connected in series in sequence, the common ends of the N equivalent inductors are connected to the first ends of N-1 equivalent capacitors in one-to-one correspondence, the second ends of the N-1 equivalent capacitors are connected to the first ends of N-1 equivalent resistors in one-to-one correspondence, and the second ends of the N-1 equivalent resistors are all grounded; Correspondingly, two ends of the line of the N equivalent inductors connected in series are respectively the input end and the output end of the low-pass filter.

3. An optical communication test device according to claim 2, characterized in that: The various elements in the low-pass filter are symmetrically structured with respect to the center point of the target connecting line, and the setting parameters of the two symmetrical elements are the same; the elements include: the equivalent inductance, the equivalent capacitance and the equivalent resistance; the target connecting line is: a connecting line connecting N equivalent inductors in series.

4. An optical communication test device according to claim 2, characterized in that: The order of the low-pass filter is positively correlated with the high-frequency suppression effect of the low-pass filter.

5. The optical communication test device according to claim 1, characterized in that: The low-pass filter is connected to the photoelectric conversion unit in the form of a microstrip line through a first connector, and the microstrip line is also connected to the data conversion unit through a second connector.

6. An optical communication test device according to claim 5, characterized in that: The microstrip line, the first connector and the second connector are all arranged on a PCB board.

7. An optical communication test device according to claim 6, characterized in that: The setting parameters of the first connector, the second connector and the PCB board are all set according to the test frequency band of the signal to be tested.

8. An optical communication test device according to claim 6, characterized in that: If the operating frequency of the low-pass filter is lower than a preset threshold, the PCB board is a Rogers board; if the operating frequency of the low-pass filter is higher than the preset threshold, the PCB board is a high-speed board.

9. The optical communication test device according to claim 5, characterized in that: The microstrip line includes: a first impedance matching line, a second impedance matching line, a high impedance line, M groups of equivalent resistors and patches connected together; M≥1; the first impedance matching line and the second impedance matching line are designed according to the structure of the PCB board; The two ends of the high impedance line are respectively connected to the first impedance matching line and the second impedance matching line, and the high impedance line is connected to M groups of equivalent resistors and patches connected together.

10. An optical communication test device according to claim 9, characterized in that: The patch is fan-shaped or rectangular.

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