Insertion loss board, test equipment, signal transmission method and program product

Abstract

The invention discloses an insertion loss board, test equipment, a signal transmission method and a program product, and is applied to the technical field of signal quality test, and the insertion loss board comprises a storage unit which is used for storing each preset signal frequency and a corresponding initial S parameter; the main control unit is used for determining a target signal frequency and a target length; the signal processing unit is used for determining the S parameter of the transmission line with the target length and extracting the insertion loss from the S parameter based on the initial S parameter corresponding to the target signal frequency and the target length; receiving an original to-be-tested signal through an input interface of a signal transmission path, and adjusting the signal transmission path based on the insertion loss so as to enable the insertion loss from the input interface to an output interface of the signal transmission path to accord with the extracted insertion loss; and signal output is carried out through an output interface of the signal transmission path. By applying the scheme of the invention, the size can be reduced on the basis of meeting the functional requirements of the insertion loss plate.

Description

Technical Field

[0001] The present invention relates to the technical field of signal quality testing, and in particular to an insertion loss board, testing equipment, a signal transmission method and a program product. Background Art

[0002] When testing the signal quality of high-speed signals, bit error rate testing is a key test item. By measuring the receiver's bit error rate, the rationality of the entire high-speed system design can be determined. During testing, the insertion loss of the signal link must be properly designed and calibrated, so an insertion loss test board is an essential auxiliary tool.

[0003] Current insertion loss boards are implemented by designing numerous differential lines of varying lengths on a single PCB (Printed Circuit Board). These lines provide varying insertion losses, and each set of differential lines is equipped with two pairs of connectors (one pair for the input and one pair for the output). This allows testers to select the appropriate differential lines for connection based on their testing needs, thus satisfying their need to construct appropriate test signals for different scenarios. However, the large number of differential lines and their associated connectors required for current insertion loss boards makes them bulky and inconvenient for testers to use.

[0004] In summary, how to provide an insertion loss board that meets functional requirements and reduces its volume is a technical problem that those skilled in the art urgently need to solve. Summary of the Invention

[0005] The object of the present invention is to provide an insertion loss board, a test device, a signal transmission method and a program product, so as to provide an insertion loss board that meets functional requirements and reduces the volume.

[0006] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0007] In a first aspect, the present invention provides an insertion loss board, comprising:

[0008] A storage unit, used to store each preset signal frequency and the corresponding initial S parameter;

[0009] The initial S parameter represents the scattering parameter of a signal of any of the signal frequencies when a transmission line with a length of L0 is used for signal transmission, where L0 is a preset initial length;

[0010] a main control unit, configured to receive a length selection instruction and a frequency selection instruction, and determine a target signal frequency specified by the frequency selection instruction and a target length specified by the length selection instruction;

[0011] A signal processing unit is configured to determine, based on the target length and initial S parameters corresponding to the target signal frequency, the S parameters of the transmission line having the target length and extract the insertion loss therefrom; receive the original signal to be measured through the input interface of its own signal transmission path, and adjust the signal transmission path based on the insertion loss so that the insertion loss from the input interface to the output interface of the signal transmission path conforms to the extracted insertion loss; and output the signal through the output interface of the signal transmission path.

[0012] On the other hand, it also includes:

[0013] A differential signal pair is provided on the insertion loss board, and a line length of the differential signal pair is equal to the initial length L0.

[0014] On the other hand, it also includes:

[0015] A display unit is used to display the target signal frequency and the target length under the control of the main control unit.

[0016] On the other hand, based on the initial S parameters corresponding to the target signal frequency and the target length, determining the S parameters of the transmission line having the target length and extracting the insertion loss therefrom includes:

[0017] Determining the value of the iteration round N and the initial S parameter corresponding to the target signal frequency; wherein N is a positive integer not less than 1;

[0018] Let i be incremented from 1 to N, and follow Perform recursive calculations to obtain S0 to S N ;

[0019] Wherein, S0 represents the initial S parameter corresponding to the target signal frequency; S i is the i-th S parameter corresponding to the target signal frequency, indicating that for the signal of the target signal frequency, the length L is used i Scattering parameter when the transmission line transmits signals; S N The Nth S parameter corresponding to the target signal frequency indicates that for the signal of the target signal frequency, the length L is used. N Scattering parameter when the transmission line transmits signals; S i-1 is the i-1th S parameter corresponding to the target signal frequency, indicating that for the signal of the target signal frequency, the length L is used. i-1 The scattering parameter of the transmission line when transmitting signals; L i is the length of the i-th round of recursive operation, Li-1 is the length value of the i-1th round of recursive operation;

[0020] Determine the multiplier value K obtained by dividing the target length by the initial length L0, and based on the obtained S0 to S N , S K-1 As the S parameter of the transmission line having the target length, the insertion loss is extracted therefrom; wherein K is a positive integer not exceeding N.

[0021] On the other hand, the signal processing unit is further configured to:

[0022] After receiving the original signal to be tested through the input interface of its own signal transmission path, the pre-processing unit in the signal transmission path performs noise reduction on the original signal to be tested.

[0023] On the other hand, adjusting the signal transmission path based on the insertion loss so that the insertion loss from the input interface to the output interface of the signal transmission path conforms to the extracted insertion loss includes:

[0024] constructing a corresponding finite length unit impulse response filter unit based on the insertion loss so that the insertion loss from the input interface to the output interface of the signal transmission path conforms to the extracted insertion loss;

[0025] Wherein, the signal transmission path includes the finite length unit impulse response filtering unit.

[0026] On the other hand, a corresponding finite length unit impulse response filter unit is constructed based on the insertion loss, including:

[0027] Converting the insertion loss into a discrete frequency response, and obtaining a time domain impulse response by performing an inverse Fourier transform on the frequency response;

[0028] The time domain impulse response is used as a filter coefficient of a finite length unit impulse response filter unit to construct a finite length unit impulse response filter unit corresponding to the insertion loss.

[0029] In a second aspect, the present invention provides a testing device comprising the insertion loss board as described above.

[0030] In a third aspect, the present invention provides a signal transmission method, which is applied to the signal processing unit of the insertion loss board as described above, comprising:

[0031] After the main control unit receives the length selection instruction and the frequency selection instruction and determines the target signal frequency specified by the frequency selection instruction and the target length specified by the length selection instruction, the main control unit determines the S parameters of the transmission line having the target length based on the target length and the initial S parameters corresponding to the target signal frequency, and extracts the insertion loss therefrom;

[0032] receiving an original signal to be tested through an input interface of its own signal transmission path, and adjusting the signal transmission path based on the insertion loss so that the insertion loss from the input interface to the output interface of the signal transmission path conforms to the extracted insertion loss;

[0033] Outputting the signal through the output interface of the signal transmission path;

[0034] Among them, the storage unit stores various preset signal frequencies and corresponding initial S parameters; the initial S parameters represent the scattering parameters when a signal of any of the signal frequencies is transmitted using a transmission line with a length of L0, where L0 is the preset initial length.

[0035] In a fourth aspect, the present invention provides a computer program product, comprising a computer program, which implements the steps of the signal transmission method described above when executed by a processor.

[0036] Using the technical solution provided by an embodiment of the present invention, a storage unit stores various preset signal frequencies and corresponding initial S parameters. The initial S parameters represent the scattering parameters for a signal at any frequency when transmitted using a transmission line of length L0, where L0 is the preset initial length. Since the initial S parameters are obtained, once a target signal frequency and target length are determined, the S parameters of the transmission line with the target length can be determined based on the initial S parameters corresponding to the target signal frequency and target length, and the insertion loss can be extracted from the S parameters. In other words, the required insertion loss is calculated for the target signal frequency and target length. Subsequently, the signal transmission path is adjusted based on the insertion loss so that the insertion loss from the input interface to the output interface of the signal transmission path matches the extracted insertion loss. This is equivalent to inserting a transmission line of varying lengths into the actual circuit, thereby changing the transmission and reflection characteristics of the signal, and thus the insertion loss of the signal transmission path. The signal outputted through the output interface of the signal transmission path is now the output signal of the original test signal after the insertion loss of the signal transmission path has been applied, thus meeting subsequent testing requirements.

[0037] As can be seen, in this application, the required insertion loss can be calculated for different applications based on the target signal frequency and target length. The signal transmission path can then be adjusted to meet the current insertion loss requirements. Therefore, this application eliminates the need for numerous transmission lines and connectors of varying lengths, as in traditional solutions. This allows for a reduced size while still meeting the functional requirements of the insertion loss board. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0039] Figure 1 A schematic structural diagram of an insertion loss plate provided in a specific embodiment of the present invention;

[0040] Figure 2 A schematic structural diagram of an insertion loss plate provided in another specific embodiment of the present invention;

[0041] Figure 3 A schematic structural diagram of a signal processing unit of an insertion loss board provided in a specific embodiment of the present invention;

[0042] Figure 4 Another structural schematic diagram of a signal processing unit of an insertion loss board provided in a specific embodiment of the present invention;

[0043] Figure 5 This is a flowchart of a signal transmission method provided in a specific embodiment of the present invention. DETAILED DESCRIPTION

[0044] The core of the present invention is to provide an insertion loss board, a test device, a signal transmission method and a program product, which can reduce the volume while meeting the functional requirements of the insertion loss board.

[0045] To help those skilled in the art better understand the present invention, the present invention is further described below in conjunction with the accompanying drawings and specific embodiments. It is apparent that the embodiments described are only a portion of the present invention, not all of the embodiments. All other embodiments derived by those skilled in the art based on the embodiments of the present invention without inventive effort are also within the scope of protection of the present invention.

[0046] Please refer to Figure 1 , Figure 1This is a schematic structural diagram of an insertion loss plate provided in a specific embodiment of the present invention. The insertion loss plate may include:

[0047] The storage unit 10 is used to store various preset signal frequencies and corresponding initial S parameters;

[0048] The initial S parameter represents the scattering parameter of a signal of any signal frequency when the signal is transmitted using a transmission line with a length of L0, where L0 is a preset initial length.

[0049] The main control unit 20 is used to receive the length selection instruction and the frequency selection instruction, and determine the target signal frequency specified by the frequency selection instruction and the target length specified by the length selection instruction;

[0050] The signal processing unit 30 is used to determine the S parameters of the transmission line with the target length based on the initial S parameters corresponding to the target length and the target signal frequency and extract the insertion loss therefrom; receive the original test signal through the input interface of its own signal transmission path, and adjust the signal transmission path based on the insertion loss so that the insertion loss from the input interface to the output interface of the signal transmission path conforms to the extracted insertion loss; and output the signal through the output interface of the signal transmission path.

[0051] Specifically, in the present application, it is necessary to predetermine each preset signal frequency and the corresponding initial S parameters, which can usually be determined through experimental data and / or theoretical analysis. For example, in a scenario where a PCIe (Peripheral Component Interconnect express, a high-speed serial computer expansion bus standard) 4.0 line needs to be tested, the signal frequency required by the PCIe 4.0 line can be used as one of the preset signal frequencies (denoted as signal frequency A), and then, through experiments, the scattering parameters of a transmission line with a length of L0 when transmitting PCIe 4.0 signals are obtained, that is, the initial S parameters of the transmission line with a length of L0 at signal frequency A are obtained, which can be simply referred to as the initial S parameters corresponding to signal frequency A. For example, in some cases, it is necessary to test the PCIe5.0 line. The signal frequency required by the PCIe5.0 line can be used as one of the preset signal frequencies (denoted as signal frequency B). Then, through experiments, the scattering parameters of the transmission line with a length of L0 when transmitting PCIe5.0 signals can be obtained. That is, the initial S parameters of the transmission line with a length of L0 at signal frequency B are obtained, which can be simply referred to as the initial S parameters corresponding to signal frequency B.

[0052] The S parameter is a scattering parameter, which is a matrix representation of the signal transmission and reflection relationship between the ports of a microwave network, and can effectively reflect the reflection and transmission characteristics at the corresponding frequency. The S parameter includes reflection parameters such as S11, S22, etc., and also includes transmission parameters such as S12, S21, etc. The S11 described here represents the reflection coefficient of the input port, which reflects the degree of reflection of the circuit for the incident signal. S22 represents the reflection coefficient of the output port, which reflects the reflection characteristics of the output port. S21 represents the transmission coefficient from the input port to the output port, which reflects the gain or loss of the signal passing through the circuit. Therefore, S21 is also the insertion loss in the S parameter. S12 represents the transmission coefficient from the output port to the input port, which reflects the isolation. In addition, if it is a differential transmission line, the insertion loss in the S parameter is usually recorded as S DD21 .

[0053] After the initial S parameters corresponding to each preset signal frequency are determined in advance, this information can be stored as an S parameter file in the storage unit 10 for use in subsequent processes. The storage unit 10 is implemented using a non-volatile memory device, and the specific type can be set and adjusted according to actual needs.

[0054] It should also be noted that L0 is a preset initial length. The specific value can be set according to actual needs, but it should be set relatively small. This is because the S parameters corresponding to various multiples of L0 can usually be calculated based on the initial S parameters according to the recursive calculation method described below. Therefore, L0 is equivalent to the minimum granularity of length division and needs to be set relatively small. This allows users to obtain the S parameters for various transmission line lengths based on the initial S parameters. For example, in one embodiment, the preset initial length L0 can be set to 1 inch.

[0055] The main control unit 20 is connected to the storage unit 10 so as to read the storage content in the storage unit 10 . In practical applications, the main control unit 20 can usually be connected to the storage unit 10 via an SPI interface or an I2C interface.

[0056] The main control unit 20 can communicate with external devices to receive the length selection instruction and frequency selection instruction sent by the staff, such as Figure 2 In the example, the main control unit 20 can communicate with the external device through the input unit. The input unit can provide USB, UART, Ethernet and other interfaces, so that the insertion loss board of the present application can be connected to the host or other test equipment for communication. The staff can then send length selection instructions and frequency selection instructions to the main control unit 20 in the insertion loss board through the host or other test equipment.

[0057] The target signal frequency specified by the frequency selection instruction indicates the frequency at which the staff needs to perform the test, and it can be understood that the target signal frequency is the signal frequency of the original signal to be tested received by the signal processing unit 30. The target length specified by the length selection instruction indicates the length of the transmission line that the staff needs the insertion loss board to provide. Of course, the insertion loss board of the present application does not need to be provided with a large number of transmission lines of different lengths. Instead, the signal transmission path is adjusted according to the required insertion loss by the signal processing unit 30, which is equivalent to inserting a transmission line of different lengths into the actual circuit. It can effectively change the transmission and reflection characteristics of the signal in the transmission network, that is, it can change the S parameters of the transmission network, of course, also including the change of insertion loss.

[0058] After obtaining the target signal frequency and target length specified by the operator, the signal processing unit 30 can obtain the initial S parameters corresponding to the target signal frequency from the storage unit 10. The signal processing unit 30 can also be connected to the storage unit 10 via an SPI interface or an I2C interface. Based on the initial S parameters corresponding to the target signal frequency and the target length, the signal processing unit 30 can calculate the S parameters of the transmission line with the target length, and then extract the insertion loss from the S parameters.

[0059] When calculating the S parameters of a transmission line of a target length, there can be a variety of specific algorithms. As long as the S parameters of the transmission line of the target length at the target signal frequency can be accurately obtained based on the S parameters of the transmission line of the L0 length at the target signal frequency (i.e., the initial S parameters), the S parameters of the transmission line of the target length at the target signal frequency can be accurately obtained.

[0060] For example, in a specific embodiment of the present invention, determining the S parameters of a transmission line having a target length and extracting the insertion loss therefrom based on the initial S parameters corresponding to the target signal frequency and the target length may specifically include:

[0061] Determine the value of the iteration round N and the initial S parameter corresponding to the target signal frequency; where N is a positive integer not less than 1;

[0062] Let i be incremented from 1 to N, and follow Perform recursive calculations to obtain S0 to S N ;

[0063] Among them, S0 represents the initial S parameter corresponding to the target signal frequency; S i The i-th S parameter corresponding to the target signal frequency indicates that for the signal of the target signal frequency, the length L is used. i The scattering parameter of the transmission line when transmitting the signal; S NThe Nth S parameter corresponding to the target signal frequency indicates that for the signal of the target signal frequency, the length L is used. N The scattering parameter of the transmission line when transmitting the signal; S i-1 The i-1th S parameter corresponding to the target signal frequency indicates that for the signal of the target signal frequency, the length L is used. i-1 The scattering parameter of the transmission line when transmitting the signal; L i is the length of the i-th round of recursive operation, L i-1 is the length value of the i-1th round of recursive operation;

[0064] Determine the multiplier value K obtained by dividing the target length by the initial length L0, and based on the obtained S0 to S N , S K-1 As the S-parameter of the transmission line with the target length, the insertion loss is extracted therefrom; wherein K is a positive integer not exceeding N.

[0065] In this embodiment, the recursive operation can be used to gradually determine the values ​​of S0 to S N , and is relatively simple and convenient in calculation.

[0066] Specifically, in this implementation, the initial S parameter corresponding to the target signal frequency is recorded as S0. Therefore, the S parameter of the transmission line with a length of L0 can be recorded as "transmission line length = L0, S parameter at this length = S0". Therefore, we can first calculate S1, that is, the S parameter of the transmission line with a length of L1 can be recorded as "transmission line length = L1 = L0 + L0, and the S parameter under this length = S1 = S0 * S0". By analogy, we can then calculate S2, that is, the S parameter of the transmission line with a length of L2 can be recorded as "transmission line length = L2 = L1 + L0, and the S parameter under this length = S2 = S1 * S0". Correspondingly, we can then calculate S3, that is, the S parameter of the transmission line with a length of L3 can be recorded as "transmission line length = L3 = L2 + L0, and the S parameter under this length = S3 = S2 * S0". Then we can calculate S4, that is, the S parameter of the transmission line with a length of L4 can be recorded as "transmission line length = L4 = L3 + L0, and the S parameter under this length = S4 = S3 * S0". By analogy, the last round is S N Calculation, that is, for L N The S parameter of a transmission line with a certain length can be expressed as "transmission line length = L N =L N-1 +L0, the S parameter at this length = S N =S N-1 *S0”

[0067] According to the above recursive operation, iterations can be performed continuously until the value of i reaches the value of the iteration round N. At this time, the signal corresponding to the target signal frequency is obtained, and the S parameters of the signal when it is transmitted in transmission lines of different lengths are obtained, that is, the S0 to S N .

[0068] Then, in this embodiment, the multiple value K obtained by dividing the target length by the initial length L0 can be determined, that is, the target length is K*L0, and then S K-1 As the S parameter of the transmission line with the target length, the insertion loss can be extracted from the S parameter. For example, in one case, L0 is 1 inch and N is 50, that is, through 50 rounds of iteration, the insertion loss from S0 to S 50 For example, if the target length is 3 inches, the multiplier value K obtained by dividing 3 inches by the initial length L0 is 3, so S2 is required as the S parameter of the transmission line with the target length.

[0069] This implementation method is based on the consideration that when the S parameters of two transmission lines are known, matrix multiplication can be performed based on the S parameters of the two transmission lines. The obtained S parameters can be used as the S parameters of the transmission line with a length equal to the sum of the two transmission lines. Therefore, starting from the initial parameter S0 of the transmission line with a length of L0, the S parameters of the transmission lines with lengths equal to multiples of L0 can be obtained through step-by-step iteration, which is computationally simple and convenient. In addition, in this implementation method, the matrix multiplication from S0 to S N Only S0 needs to be obtained in advance through experimental data and / or theoretical analysis, and the rest can be obtained through recursive calculations, so there is no need to do a lot of accurate work in advance.

[0070] In addition, it is understandable that in this embodiment, the target length specified by the staff needs to be an integer multiple of the initial length L0. Therefore, in some embodiments, when the user inputs the length selection instruction, the input method can be restricted so that the specified target length is an integer multiple of the initial length L0, for example, only allowing the user to select the target length through a drop-down option. In another case, a button can be provided to the staff through the input unit. For example, after the insertion loss board is powered on and the target signal frequency is determined, if the staff does not press the button, the initial length L0 is used as the target length by default. When the staff presses the button once, the target length will become 2*L0. When the staff presses the button again, the target length will become 3*L0, and so on. When the target length reaches L NWhen the staff presses the button again, the target length will return to L0. It can be seen that in this example, due to the limitation of the input method, the staff can only set the target length to an integer multiple of the initial length L0, and no other values ​​will appear.

[0071] In a specific embodiment of the present invention, it may further include: a display unit for displaying the target signal frequency and target length under the control of the main control unit 20. Figure 2 In this embodiment, the display unit is connected to the main control unit, allowing the target signal frequency and target length to be displayed on the display unit, making it easier for personnel to view and reminding them of the currently selected signal frequency and line length. Of course, in other embodiments, the display unit may also display other content as needed, without affecting the implementation of the present invention. Figure 2 Also shown is a power module that can power the entire insertion loss board.

[0072] After the signal processing unit 30 determines the S parameters of the transmission line with the target length and extracts the insertion loss therefrom, it is necessary to adjust its own signal transmission path so that the insertion loss from the input interface to the output interface of the signal transmission path meets the extracted insertion loss. The specific implementation can be set as needed to achieve the purpose of insertion loss adjustment.

[0073] For example, in a specific embodiment of the present invention, adjusting the signal transmission path based on the insertion loss so that the insertion loss from the input interface to the output interface of the signal transmission path conforms to the extracted insertion loss may specifically include:

[0074] Constructing a corresponding finite length unit impulse response filter unit based on the insertion loss so that the insertion loss from the input interface to the output interface of the signal transmission path conforms to the extracted insertion loss;

[0075] Wherein, the signal transmission path includes a finite length unit impulse response filter unit.

[0076] In this embodiment, the signal transmission path of the signal processing unit 30 includes a FIR (Finite Impulse Response) filter unit. By setting the FIR filter unit differently, different filtering performances can be achieved, that is, the required insertion loss effect can be achieved.

[0077] Specifically, it is necessary to construct a corresponding finite length unit impulse response filter unit according to the required insertion loss, so that the insertion loss from the input interface to the output interface of the signal transmission path meets the required insertion loss, that is, after the original signal to be measured passes through the FIR filter unit, the insertion loss meets the required insertion loss.

[0078] Furthermore, in a specific embodiment of the present invention, constructing a corresponding finite length unit impulse response filter unit based on insertion loss may specifically include:

[0079] The insertion loss is converted into a discrete frequency response, and the time domain impulse response is obtained by performing an inverse Fourier transform on the frequency response;

[0080] The time domain impulse response is used as the filter coefficient of a finite length unit impulse response filter unit, and a finite length unit impulse response filter unit corresponding to the insertion loss is constructed.

[0081] This implementation method takes into account that, when constructing the corresponding FIR filter unit according to the required insertion loss, the insertion loss can be first converted into a discrete frequency response, and then the frequency response is inverse Fourier transformed to obtain a time domain impulse response, which is then used as the filter coefficient of the FIR filter unit to realize the construction of the FIR filter unit. At this time, the insertion loss of the constructed FIR filter unit can be well consistent with the required insertion loss.

[0082] In addition, it should be noted that the FIR filter unit described in this embodiment can be implemented by an analog circuit or a digital circuit. Considering that the signal processing unit 30 can usually be a DSP, a digital filter can be constructed in the DSP, that is, an FIR filter unit is constructed in the DSP according to the required insertion loss.

[0083] After the original test signal is processed by the signal transmission path, it can be output through the output interface of the signal processing unit 30. After the output, it can be tested. For example, in actual applications, the bit error rate and other items can be tested.

[0084] In a specific embodiment of the present invention, it may further include:

[0085] A differential signal pair is provided on the insertion loss board, and the line length of the differential signal pair is equal to the initial length L0. As can be seen from the above description, in the present application scheme, it is necessary to predetermine each preset signal frequency and the corresponding initial S parameters. The initial S parameters represent the scattering parameters when a transmission line with a length of L0 is used to transmit a signal of a certain signal frequency. In other words, a transmission line with a length of L0 can be used to obtain the S parameters of a transmission line with a length of L0 at different signal frequencies through experiments. In this embodiment, a differential signal pair with a length of L0 is directly provided on the insertion loss board, so that the staff does not need to look for a transmission line with a length of L0 separately, and the insertion loss board can provide it. Figure 2 In the example, a differential signal pair with a line length equal to the initial length L0 is shown in the lower left corner of the insertion loss board, which is recorded as a standard differential pair. Figure 2 In the example, the input port of the signal processing unit 30 is specifically a differential signal input port, and accordingly, the input port of the signal processing unit 30 is specifically a differential signal output port.

[0086] In addition, it should be noted that the differential signal pair with a line length equal to the initial length L0 is set in this embodiment. This is because in most cases, the original test signal is a differential signal, that is, the present application scheme is usually applied in the case of differential signals. Of course, if the original test signal is a single-ended signal, the insertion loss board can also be set according to the principle of the present application scheme. That is, whether it is a differential signal or a single-ended signal, after applying the present application scheme, the principle is the same. However, in the case of differential transmission, it is necessary to conduct experiments in advance according to the differential signal pair with a line length equal to the initial length L0 to obtain the corresponding S parameters at different signal frequencies. In the case of single-ended transmission, it is necessary to conduct experiments in advance according to the single-ended signal line with a line length equal to the initial length L0 to obtain the corresponding S parameters at different signal frequencies.

[0087] In a specific embodiment of the present invention, the signal processing unit 30 may also be used to:

[0088] After receiving the original signal to be tested through the input interface of its own signal transmission path, the pre-processing unit in the signal transmission path performs noise reduction on the original signal to be tested.

[0089] This implementation allows for noise reduction of the original test signal through a preprocessing unit in the signal transmission path to ensure signal quality, which also helps improve the reliability of subsequent tests. Furthermore, it is understood that the preprocessing unit can also be a digital circuit, specifically implemented via a DSP. In addition to noise reduction, in some implementations, the preprocessing unit can also add other functions based on actual needs, such as gain adjustment and phase adjustment of the original test signal as needed.

[0090] Figure 3 The preprocessing unit of this embodiment is used, and the signal processing unit 30 is specifically implemented by DSP. The original signal to be measured is a time domain signal and an analog signal. Therefore, it is necessary to set an analog-to-digital conversion unit at the input end of the signal processing unit 30, and set a digital-to-analog conversion unit at the output end of the signal processing unit 30, so that the input signal and output signal of the signal processing unit 30 are both time domain signals and analog signals.

[0091] In a specific embodiment of the present invention, the signal processing unit 30 may be further configured to: use the signal output by the finite length unit impulse response filter unit as a feedback signal and feed it back to the input end of the finite length unit impulse response filter unit.

[0092] This embodiment takes into account that, in the above embodiment, the required insertion loss can be achieved by the FIR filter unit, and in order to make the signal processing unit 30 process the original test signal closer to the actual situation, that is, closer to using the required length of the transmission line to provide the required insertion loss, in this embodiment, reference can be made to Figure 4 The signal output by the finite-length unit impulse response filter unit can also be used as a feedback signal and fed back to the input end of the finite-length unit impulse response filter unit, thereby effectively simulating the reflection characteristics during signal transmission, and making the processing of the original test signal by the signal processing unit 30 closer to the actual situation, which is conducive to ensuring the accuracy of the test.

[0093] Using the technical solution provided by the embodiments of the present invention, the storage unit 10 stores various preset signal frequencies and corresponding initial S parameters. The initial S parameters represent the scattering parameters for a signal at any frequency when transmitted using a transmission line of length L0, where L0 is the preset initial length. Since the initial S parameters are obtained, once the target signal frequency and target length are determined, the S parameters of the transmission line with the target length can be determined based on the initial S parameters corresponding to the target signal frequency and the target length, and the insertion loss can be extracted from the S parameters. In other words, the required insertion loss is calculated for the required target signal frequency and target length. Subsequently, the signal transmission path is adjusted based on the insertion loss so that the insertion loss from the input interface to the output interface of the signal transmission path matches the extracted insertion loss. This is equivalent to inserting a transmission line of varying lengths into the actual circuit, thereby changing the transmission and reflection characteristics of the signal, and thus the insertion loss of the signal transmission path. At this point, the signal outputted through the output interface of the signal transmission path is the output signal of the original test signal after the insertion loss provided by the signal transmission path has been reduced, thus meeting subsequent testing requirements.

[0094] It can be seen that in the present application, for different occasions, the required insertion loss can be calculated according to the required target signal frequency and target length, and then the insertion loss can be adjusted to meet the current needs by adjusting the signal transmission path. Therefore, the present application does not need to set up a large number of transmission lines and connectors of different lengths as in the traditional solution, and the volume can be reduced on the basis of meeting the functional requirements of the insertion loss board.

[0095] Corresponding to the above embodiments of the insertion loss board, an embodiment of the present invention further provides a testing device, which may include the insertion loss board as in any of the above embodiments, and may refer to the above for reference.

[0096] An embodiment of the present invention further provides a signal transmission method, which can be applied to a signal processing unit of an insertion loss board in any of the above embodiments, comprising the following steps:

[0097] Step S101: After the main control unit receives the length selection instruction and the frequency selection instruction and determines the target signal frequency specified by the frequency selection instruction and the target length specified by the length selection instruction, the main control unit determines the S parameters of the transmission line with the target length based on the initial S parameters corresponding to the target length and the target signal frequency and extracts the insertion loss therefrom;

[0098] Step S102: receiving the original test signal through the input interface of its own signal transmission path, and adjusting the signal transmission path based on the insertion loss so that the insertion loss from the input interface to the output interface of the signal transmission path conforms to the extracted insertion loss;

[0099] Step S103: outputting the signal through the output interface of the signal transmission path;

[0100] The storage unit stores various preset signal frequencies and corresponding initial S parameters; the initial S parameters represent the scattering parameters for a signal of any signal frequency when a transmission line with a length of L0 is used for signal transmission, where L0 is the preset initial length.

[0101] An embodiment of the present invention further provides a computer program product, which can be referenced in correspondence with the above.

[0102] The computer program product includes a computer program / instruction, which implements the steps of the signal transmission method in any of the above embodiments when executed by a processor.

[0103] It should also be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or device. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of additional identical elements in the process, method, article, or device comprising the element.

[0104] Professionals may further appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the composition and steps of each example have been generally described in terms of function in the above description. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professionals and technicians can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention. Specific examples are used herein to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the technical solution and core ideas of the present invention. It should be pointed out that for ordinary technicians in this technical field, without departing from the principles of the present invention, the present invention can also be improved and modified in a number of ways, and these improvements and modifications also fall within the scope of protection of the present invention.

Claims

1. An insertion loss board, characterized in that: include: A storage unit, used to store each preset signal frequency and the corresponding initial S parameter; The initial S parameter represents the scattering parameter of a signal of any of the signal frequencies when a transmission line with a length of L0 is used for signal transmission, where L0 is a preset initial length; a main control unit, configured to receive a length selection instruction and a frequency selection instruction, and determine a target signal frequency specified by the frequency selection instruction and a target length specified by the length selection instruction; A signal processing unit is configured to determine, based on the target length and initial S parameters corresponding to the target signal frequency, the S parameters of the transmission line having the target length and extract the insertion loss therefrom; receive the original signal to be measured through the input interface of its own signal transmission path, and adjust the signal transmission path based on the insertion loss so that the insertion loss from the input interface to the output interface of the signal transmission path conforms to the extracted insertion loss; and output the signal through the output interface of the signal transmission path.

2. The insertion loss plate according to claim 1, wherein: Also includes: A differential signal pair is provided on the insertion loss board, and a line length of the differential signal pair is equal to the initial length L0.

3. The insertion loss plate according to claim 1, wherein: Also includes: A display unit is used to display the target signal frequency and the target length under the control of the main control unit.

4. The insertion loss plate according to claim 1, wherein: Determining the S parameters of a transmission line having the target length based on the initial S parameters corresponding to the target signal frequency and the target length, and extracting the insertion loss therefrom, comprising: Determining the value of the iteration round N and the initial S parameter corresponding to the target signal frequency; wherein N is a positive integer not less than 1; Let i be incremented from 1 to N, and follow Perform recursive calculations to obtain S0 to S N ; Wherein, S0 represents the initial S parameter corresponding to the target signal frequency; S i is the i-th S parameter corresponding to the target signal frequency, indicating that for the signal of the target signal frequency, the length L is used i Scattering parameter when the transmission line transmits signals; S N The Nth S parameter corresponding to the target signal frequency indicates that for the signal of the target signal frequency, the length L is used. N Scattering parameter when the transmission line transmits signals; S i-1 is the i-1th S parameter corresponding to the target signal frequency, indicating that for the signal of the target signal frequency, the length L is used. i-1 The scattering parameter of the transmission line when transmitting signals; L i is the length of the i-th round of recursive operation, L i-1 is the length value of the i-1th round of recursive operation; Determine the multiplier value K obtained by dividing the target length by the initial length L0, and based on the obtained S0 to S N , S K-1 As the S parameter of the transmission line having the target length, the insertion loss is extracted therefrom; wherein K is a positive integer not exceeding N.

5. The insertion loss plate according to claim 1, wherein: The signal processing unit is further configured to: After receiving the original signal to be tested through the input interface of its own signal transmission path, the pre-processing unit in the signal transmission path performs noise reduction on the original signal to be tested.

6. The insertion loss plate according to any one of claims 1 to 5, characterized in that: Adjusting the signal transmission path based on the insertion loss so that the insertion loss from the input interface to the output interface of the signal transmission path conforms to the extracted insertion loss, comprising: constructing a corresponding finite length unit impulse response filter unit based on the insertion loss so that the insertion loss from the input interface to the output interface of the signal transmission path conforms to the extracted insertion loss; Wherein, the signal transmission path includes the finite length unit impulse response filtering unit.

7. The insertion loss plate according to claim 6, wherein: A corresponding finite length unit impulse response filter unit is constructed based on the insertion loss, including: Converting the insertion loss into a discrete frequency response, and obtaining a time domain impulse response by performing an inverse Fourier transform on the frequency response; The time domain impulse response is used as a filter coefficient of a finite length unit impulse response filter unit to construct a finite length unit impulse response filter unit corresponding to the insertion loss.

8. A testing device, characterized in that: Comprising the insertion loss board according to any one of claims 1 to 7.

9. A signal transmission method, characterized in that: A signal processing unit applied to the insertion loss board according to any one of claims 1 to 7, comprising: After the main control unit receives the length selection instruction and the frequency selection instruction and determines the target signal frequency specified by the frequency selection instruction and the target length specified by the length selection instruction, the main control unit determines the S parameters of the transmission line having the target length based on the target length and the initial S parameters corresponding to the target signal frequency, and extracts the insertion loss therefrom; receiving an original signal to be tested through an input interface of its own signal transmission path, and adjusting the signal transmission path based on the insertion loss so that the insertion loss from the input interface to the output interface of the signal transmission path conforms to the extracted insertion loss; Outputting the signal through the output interface of the signal transmission path; Among them, the storage unit stores various preset signal frequencies and corresponding initial S parameters; the initial S parameters represent the scattering parameters when a signal of any of the signal frequencies is transmitted using a transmission line with a length of L0, where L0 is the preset initial length.

10. A computer program product comprising a computer program, characterized in that When the computer program is executed by a processor, the steps of the signal transmission method according to claim 9 are implemented.

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