Signal quality improvement method and waveform generator

Abstract

This application discloses a signal quality improvement method and a waveform generator. The signal quality improvement method includes acquiring preset output signal parameters of the waveform generator; determining a current compensation coefficient corresponding to the preset output signal parameters; and performing flatness compensation on the digital baseband signal generated by the waveform generator according to the current compensation coefficient. The current compensation coefficient makes the frequency response characteristics of the signal output by the waveform generator after compensation exhibit a state opposite to the frequency response characteristics of the transmission link, thereby improving the spectral flatness of the signal output by the waveform generator after passing through the transmission link. Since the frequency response characteristics of the compensated digital baseband signal after passing through the transmission link are consistent with the frequency response characteristics of the digital baseband signal before compensation, the compensated digital baseband signal can accurately reflect the frequency response characteristics of the device under test when output to the device under test through the transmission link.

Description

Technical Field

[0001] This application relates to the field of signal compensation technology, specifically to a signal quality improvement method and waveform generator. Background Technology

[0002] When a waveform generator is connected to the device under test, an electrical connector or a long cable is often required. The signal output by the waveform generator is then output to the device under test via an electrical adapter or a long cable.

[0003] Currently, waveform generators generally use adaptive adjustment to compensate for the frequency response characteristics of the channel, so that the output signal of the waveform generator is a signal with high flatness. After passing through electrical connectors or long cables, the output signal of the waveform generator is affected by the frequency response characteristics of electrical connectors or long cables, resulting in a decrease in the flatness of the output signal after passing through electrical connectors or long cables, thereby affecting the output results of the device under test. Summary of the Invention

[0004] The main technical problem this application addresses is the decrease in signal flatness when output through electrical connectors or long cables in related technologies, which affects the output results of the device under test.

[0005] According to a first aspect, one embodiment of this application provides a signal quality improvement method applied to a waveform generator that generates vector signals, the waveform generator being configured to connect to a device under test via a transmission link, the signal quality improvement method comprising:

[0006] Obtain the preset output signal parameters of the waveform generator;

[0007] Determine the current compensation coefficient corresponding to the preset output signal parameters;

[0008] The digital baseband signal generated by the waveform generator is flattened according to the current compensation coefficient. The current compensation coefficient makes the frequency response characteristics of the signal output by the waveform generator after compensation present an opposite state to the frequency response characteristics of the transmission link, so as to improve the spectral flatness of the signal output by the waveform generator after passing through the transmission link.

[0009] In one embodiment, determining the current compensation coefficient corresponding to the preset output signal parameters includes:

[0010] Based on the preset output signal parameters, it is determined whether to update the current compensation coefficient. If yes, a new compensation coefficient is determined based on the first characteristic data and the second characteristic data, and the current compensation coefficient is updated to the new compensation coefficient and stored. If no, the previously stored historical current compensation coefficient in the waveform generator is used as the current compensation coefficient. The first characteristic data is the frequency response characteristic data in the overall frequency response characteristic data of the waveform generator corresponding to the preset output signal parameters. The second characteristic data is the frequency response characteristic data corresponding to the preset output signal parameters in the overall frequency response characteristic data of the transmission link.

[0011] In one embodiment, the preset output signal parameters include at least the current center frequency and current signal bandwidth set by the waveform generator; the step of determining whether to update the current compensation coefficient based on the preset output signal parameters includes:

[0012] When the current center frequency of the waveform generator changes compared to the historically set center frequency and / or the current signal bandwidth of the waveform generator changes compared to the historically set signal bandwidth, the current compensation coefficient is updated.

[0013] When the current center frequency of the waveform generator has not changed compared to the historically set center frequency and the current signal bandwidth of the waveform generator has not changed compared to the historically set signal bandwidth, the historical current compensation coefficient is the current compensation coefficient.

[0014] In one embodiment, determining the new compensation coefficient based on the first characteristic data and the second characteristic data includes:

[0015] The first characteristic data and the second characteristic data are superimposed with S-parameters to obtain the first overall characteristic data;

[0016] Calculate the new compensation coefficient based on the first overall characteristic data.

[0017] In one embodiment, the transmission link includes at least one electrical connector, and the overall frequency response characteristic data of the transmission link includes the frequency response characteristic data of each electrical connector; when multiple electrical connectors are provided, the step of superimposing the first characteristic data and the second characteristic data using S-parameters to obtain the first overall characteristic data includes:

[0018] The frequency response characteristic data of each electrical connector is superimposed with the frequency response characteristic data corresponding to the preset output signal parameters by S-parameters to obtain the second overall characteristic data.

[0019] The second overall characteristic data and the first characteristic data are superimposed using S-parameters to obtain the first overall characteristic data.

[0020] In one embodiment, the step of performing flatness compensation on the digital baseband signal generated by the waveform generator according to the current compensation coefficient further includes:

[0021] In response to the first operation, the signal generation parameters of the waveform generator are obtained, wherein the first operation is used to enable the mode without absolute power compensation.

[0022] Determine the current first power compensation value corresponding to the signal generation parameters;

[0023] The digital baseband signal is power compensated according to the current first power compensation value;

[0024] or;

[0025] In response to the second operation, the signal generation parameters of the waveform generator are obtained, the second operation being used to enable the absolute power compensation mode;

[0026] Determine the current second power compensation value corresponding to the signal generation parameters;

[0027] The digital baseband signal is power compensated according to the current second power compensation value.

[0028] In one embodiment, determining the current first power compensation value corresponding to the signal generation parameters includes:

[0029] Based on the signal generation parameters, determine whether to update the current first power compensation value; if yes, determine a new first power compensation value based at least on the first characteristic data, and update the current first power compensation value to the new first power compensation value; if no, use the previously stored historical current first power compensation value in the waveform generator as the current first power compensation value and store it.

[0030] or;

[0031] Based on the signal generation parameters, determine whether to update the current second power compensation value; if yes, determine a new second power compensation value based at least on the first characteristic data and the second characteristic data, update the current second power compensation value to the new second power compensation value, and store it; if no, use the historical current second power compensation value stored in the waveform generator at the previous moment as the current second power compensation value.

[0032] Wherein, the first characteristic data is the frequency response characteristic data in the overall frequency response characteristic data of the waveform generator corresponding to the signal generation parameters; the second characteristic data is the frequency response characteristic data corresponding to the signal generation parameters in the overall frequency response characteristic data of the transmission link.

[0033] In one embodiment, the signal generation parameters include at least the signal sampling rate; the step of determining whether to update the current first power compensation value based on the signal generation parameters includes:

[0034] When the current signal sampling rate of the waveform generator changes compared to the historically set signal sampling rate, the current first power compensation value is updated.

[0035] When the current signal sampling rate of the waveform generator has not changed compared with the historically set signal sampling rate, the historical current first power compensation value is the current first power compensation value.

[0036] The step of determining whether to update the current second power compensation value based on the signal generation parameters includes:

[0037] When the current signal sampling rate of the waveform generator changes compared to the historically set signal sampling rate, the current second power compensation value is updated.

[0038] When the current signal sampling rate of the waveform generator has not changed compared with the historically set signal sampling rate, the historical current second power compensation value is the current second power compensation value.

[0039] In one embodiment, determining the new first power compensation value based at least on first characteristic data includes:

[0040] The new first power compensation value is calculated and determined based on the baseband signal power spectrum of the waveform generator and the first characteristic data.

[0041] In one embodiment, determining the new second power compensation value based at least on the first characteristic data and the second characteristic data includes:

[0042] The first characteristic data and the second characteristic data are superimposed with S-parameters to obtain the first overall characteristic data;

[0043] The new second power compensation value is calculated based on the first overall characteristic data and the baseband signal power spectrum of the waveform generator.

[0044] In one embodiment, the transmission link includes at least one electrical connector, and the overall frequency response characteristic data of the transmission link includes the frequency response characteristic data of each electrical connector; when multiple electrical connectors are provided, the step of superimposing the first characteristic data and the second characteristic data using S-parameters to obtain the first overall characteristic data includes:

[0045] The S-parameters are superimposed on the frequency response characteristic data corresponding to the preset output signal parameters in the overall frequency response characteristic data of the transmission link to obtain the second overall characteristic data.

[0046] The second overall characteristic data and the first characteristic data are superimposed using S-parameters to obtain the first overall characteristic data.

[0047] According to a second aspect, this application provides a waveform generator, comprising:

[0048] At least one processor;

[0049] and a memory communicatively connected to the at least one processor;

[0050] The memory stores instructions that can be executed by the at least one processor, which, when executed by the at least one processor, enables the at least one processor to perform the signal quality improvement method described above.

[0051] According to the signal quality improvement method and waveform generator of the above embodiments, since the digital baseband signal is flattened by the current compensation coefficient, the frequency response characteristics of the digital baseband signal are made to be opposite to the frequency response characteristics of the transmission link. The frequency response characteristics of the compensated digital baseband signal after passing through the transmission link are consistent with the frequency response characteristics of the digital baseband signal before compensation. Therefore, when the compensated digital baseband signal is output to the device under test through the transmission link, it can correctly reflect the frequency response characteristics of the device under test. Attached Figure Description

[0052] Figure 1 The flatness of the output signal of the waveform generator in the prior art;

[0053] Figure 2 To determine the flatness of the output signal via an electrical connector in existing technologies;

[0054] Figure 3 This is a block diagram illustrating the connection principle between a waveform generator and the device under test in one embodiment.

[0055] Figure 4 This is a flowchart of flatness compensation in one embodiment;

[0056] Figure 5 In one embodiment, this refers to the flatness of the waveform generator output signal after compensation by the current compensation coefficient.

[0057] Figure 6 This refers to the flatness of the signal output after passing through the transmission link in one embodiment.

[0058] Figure 7 This serves as the basis for updating the compensation coefficient in one embodiment;

[0059] Figure 8 This is a flowchart of updating the compensation coefficients in one embodiment;

[0060] Figure 9 This is a flowchart illustrating the calculation of first overall characteristic data when flatness compensation is applied to multiple electrical connectors in one embodiment.

[0061] Figure 10 This is a flowchart of an embodiment where absolute power compensation is not required.

[0062] Figure 11 This serves as the basis for updating the current first power compensation value in one embodiment;

[0063] Figure 12 This is a flowchart illustrating the specific process of updating the current first power compensation value in one embodiment;

[0064] Figure 13 This serves as the basis for updating the current second power compensation value in one embodiment;

[0065] Figure 14 This is a flowchart illustrating the specific process of updating the current second power compensation value in one embodiment;

[0066] Figure 15 This is a flowchart illustrating the calculation of first overall characteristic data when power-compensating multiple electrical connectors in one embodiment;

[0067] Figure 16 This is a flowchart of a signal quality improvement method in one embodiment. Detailed Implementation

[0068] The present invention will now be described in further detail with reference to specific embodiments and accompanying drawings. Similar elements in different embodiments are referred to by associated similar element reference numerals. In the following embodiments, many details are described to facilitate a better understanding of this application. However, those skilled in the art will readily recognize that some features may be omitted in different situations, or may be replaced by other elements, materials, or methods. In some cases, certain operations related to this application are not shown or described in the specification. This is to avoid obscuring the core parts of this application with excessive description. For those skilled in the art, detailed description of these related operations is not necessary; they can fully understand the related operations based on the description in the specification and general technical knowledge in the art.

[0069] Furthermore, the features, operations, or characteristics described in the specification can be combined in any suitable manner to form various embodiments. At the same time, the order of the steps or actions in the method description can be changed or adjusted in a manner obvious to those skilled in the art. Therefore, the various orders in the specification and drawings are only for the clear description of a particular embodiment and do not imply a necessary order, unless otherwise stated that a particular order must be followed.

[0070] The serial numbers assigned to components in this document, such as "first" and "second," are used only to distinguish the described objects and have no sequential or technical meaning. The terms "connection" and "linkage" used in this application, unless otherwise specified, include both direct and indirect connections (linkages).

[0071] When connecting the device under test (DUT) to a waveform generator, electrical connectors or long cables are often required. The measurement signal output by the waveform generator will be affected by the frequency response of the electrical connector or cable, which may result in power attenuation or changes in the signal spectrum. As a result, after connecting the DUT, the input signal has already been affected by the frequency response characteristics of the electrical connector, and the signal output by the electrical connector cannot accurately reflect the frequency response characteristics of the DUT.

[0072] The waveform generator can be a vector signal source, such as... Figure 1 As shown, the signal output from the vector signal source is a signal with high flatness before it reaches the electrical connector or cable. For example... Figure 2 As shown, the frequency response characteristics of the signal output from the vector signal source are affected by the electrical connector after passing through the electrical connector or cable, resulting in a decrease in signal flatness before reaching the device under test, which will ultimately affect the output result of the signal through the device under test.

[0073] To ensure the output results of the device under test (DUT), relevant technologies employ several methods: using electrical connectors compatible with the test frequency band; reverse derivation; built-in calibration modules; or built-in adaptive filters to compensate for frequency response characteristics by adjusting filter coefficients. Among these, using electrical connectors compatible with the test frequency band is costly and operates within a specific frequency band; changing the frequency band requires replacing the connector. Different connectors introduce different power and phase effects, compromising the stability of the final output signal. Reverse derivation is intuitive but cannot immediately reflect the DUT's frequency response characteristics at a specific frequency band, limiting its flexibility in real-time testing environments. Built-in calibration modules require hardware support, increasing costs, and existing products cannot be easily upgraded via software; recalibration is required every time a connection is changed, making the process cumbersome. Built-in adaptive filters, however, generally only reduce power and cannot maintain the output power at the same setting value, leading to variations in output signal power depending on different filter configurations.

[0074] Based on this, this application provides a signal quality improvement method, which performs flatness compensation on the digital baseband signal using the current compensation coefficient, so that the frequency response characteristics of the digital baseband signal present a state opposite to the frequency response characteristics of the transmission link. The frequency response characteristics of the compensated digital baseband signal after passing through the transmission link are consistent with the frequency response characteristics of the digital baseband signal before compensation, that is, the true state of the digital baseband signal. Therefore, when the compensated digital baseband signal is output to the device under test through the transmission link, it can correctly reflect the frequency response characteristics of the device under test.

[0075] In some embodiments, the signal quality improvement method can be applied to a waveform generator that generates vector signals, such as... Figure 3 The waveform generator shown is configured to connect to the device under test via a transmission link. For example... Figure 4 As shown, a method for improving signal quality may include the following steps:

[0076] S100: Obtain the preset output signal parameters of the waveform generator;

[0077] S200, Determine the current compensation coefficient corresponding to the preset output signal parameters;

[0078] S300: Perform flatness compensation on the digital baseband signal generated by the waveform generator according to the current compensation coefficient.

[0079] In some embodiments, the waveform generator is equipped with an operation panel. Output signal parameters can be set via the operation panel before generating the digital baseband signal; that is, the output signal parameters can be preset. The FPGA (Field-Programmable Gate Array) chip can generate the digital baseband signal based on the output signal parameters.

[0080] In some embodiments, after the FPGA chip obtains the output signal parameters set on the operation panel, it determines the current compensation coefficient for compensating the digital baseband signal when generating the digital baseband signal based on the preset output signal parameters. After the current compensation coefficient is determined, the generated digital baseband signal is preprocessed using the current compensation coefficient corresponding to the preset output signal parameters, and the compensated digital baseband signal is output. When the compensated digital baseband signal is output through the RF channel of the waveform generator, it exhibits a frequency response characteristic opposite to that of the transmission link. For example... Figure 5 The figure shows the flatness of the digital baseband signal output by the waveform generator after compensation by the current compensation coefficient, compared with... Figure 2 Compared to the flatness of the digital baseband signal output from the transmission link, the frequency response characteristics of the digital baseband signal output from the waveform generator after compensation by the current compensation coefficient are opposite to those of the transmission link, in order to improve the flatness of the signal output from the waveform generator after passing through the transmission link.

[0081] Because the digital baseband signal output by the waveform generator after compensation by the current compensation coefficient is flat after passing through the transmission link, such as... Figure 6 As shown. Therefore, the frequency response characteristics of the compensated digital baseband signal after transmission link are consistent with those of the digital baseband signal before compensation, that is, the true state of the digital baseband signal. When the compensated digital baseband signal is output to the device under test through the transmission link, it can correctly reflect the frequency response characteristics of the device under test, ensuring the accuracy of subsequent measurements. Moreover, the current compensation coefficient can be updated according to the actual situation, thus ensuring the accuracy of compensation, without the need to replace different hardware, such as connectors; and without the need for a built-in calibration module, which reduces costs.

[0082] In some embodiments, such as Figure 7 As shown, the current compensation coefficients corresponding to the preset output signal parameters are determined, including:

[0083] S201. Determine whether to update the current compensation coefficient based on the preset output signal parameters.

[0084] In some embodiments, when it is necessary to update the current compensation coefficient, a new compensation coefficient can be determined based on the first characteristic data and the second characteristic data, and the current compensation coefficient can be updated to the new compensation coefficient and stored. That is, when it is necessary to update the current compensation coefficient, a new coefficient is determined according to the first characteristic data and the second characteristic data, and the new coefficient is stored in the FPGA chip as the current compensation coefficient. When the waveform generator generates a digital baseband signal, the new coefficient can be used to compensate the digital baseband signal.

[0085] When there is no need to update the current compensation coefficient, the previously stored historical current compensation coefficient in the waveform generator is used as the current compensation coefficient. In other words, when there is no need to update the current compensation coefficient, the previously calculated current compensation coefficient is used, that is, the stored historical current compensation coefficient is used as the current compensation coefficient.

[0086] The first characteristic data is the frequency response characteristic data in the overall frequency response characteristic data of the waveform generator corresponding to the preset output signal parameters; the second characteristic data is the frequency response characteristic data corresponding to the preset output signal parameters in the overall frequency response characteristic data of the transmission link.

[0087] It should be noted that different preset output signal parameters correspond to different frequency response characteristics in the overall frequency response characteristic data of the waveform generator. Similarly, different preset output signal parameters correspond to different frequency response characteristics in the overall frequency response characteristic data of the transmission link.

[0088] In some embodiments, the overall frequency response characteristics of the waveform generator and the overall frequency response characteristics of the transmission link can be measured in advance by external devices. Then, the measured overall frequency response characteristics of the waveform generator and the overall frequency response characteristics of the transmission link are imported into the FPGA chip.

[0089] In some embodiments, the external device may be a network analyzer, that is, the network analyzer measures the overall frequency response characteristics of the waveform generator and the overall frequency response characteristics of the transmission link.

[0090] In some embodiments, the preset output signal parameters include at least the current center frequency and current signal bandwidth set by the waveform generator. In one specific embodiment, the preset output signal parameters are the current center frequency and current signal bandwidth set by the waveform generator; the current center frequency refers to the currently set center frequency when generating the digital baseband signal; the current signal bandwidth refers to the current signal bandwidth when generating the digital baseband signal. The current center frequency and current signal bandwidth can be determined by those skilled in the art according to actual needs, and are not limited in detail here.

[0091] In some embodiments, determining whether to update the current compensation coefficient based on preset output signal parameters includes:

[0092] Update the current compensation coefficients when the current center frequency of the waveform generator changes compared to the historically set center frequency and / or the current signal bandwidth of the waveform generator changes compared to the historically set signal bandwidth.

[0093] When the current center frequency of the waveform generator has not changed compared to the historically set center frequency, and the current signal bandwidth of the waveform generator has not changed compared to the historically set signal bandwidth, the historical current compensation coefficient is the current compensation coefficient.

[0094] When using a waveform generator, the current center frequency may be reset; the current center bandwidth may be reset; both the current center frequency and the current center bandwidth may be reset; or neither the current center frequency nor the current center bandwidth may be reset.

[0095] In some embodiments, the corresponding frequency response characteristic data, i.e., the first characteristic data, is selected based on the overall frequency response characteristic data of the waveform generator using the current center frequency and the current center bandwidth. The corresponding frequency response characteristic data, i.e., the second characteristic data, is selected based on the overall frequency response characteristic data of the transmission link using the current center frequency and the current center bandwidth. When either or both of the current center frequency and the current center bandwidth are reset, the first and second characteristic data need to be reselected. When the first and / or second characteristic data change, the current compensation coefficients need to be re-determined, i.e., the current compensation coefficients need to be updated.

[0096] If the current center frequency and current center bandwidth are not reset, the first characteristic data and the second characteristic data will not change. Therefore, the previously stored historical current compensation coefficients can be used, that is, there is no need to update the current compensation coefficients.

[0097] In some embodiments, such as Figure 8 As shown, determining new compensation coefficients based on the first characteristic data and the second characteristic data includes the following steps:

[0098] S2011. The first characteristic data and the second characteristic data are superimposed with S-parameters to obtain the first overall characteristic data;

[0099] S2012. Calculate the new compensation coefficient based on the first overall characteristic data.

[0100] In some embodiments, the transmission link includes at least one electrical connector. When the at least one electrical connector is a single connector, the overall frequency response characteristic data of the transmission link is the overall frequency response characteristic data of that single connector. The second characteristic data is the frequency response characteristic data corresponding to the overall frequency response characteristic data of that single connector selected based on the current center frequency and the current center bandwidth. The FPGA chip superimposes the first and second characteristic data using S-parameters to obtain the first overall characteristic data, and further calculates new compensation coefficients based on the first overall characteristic data.

[0101] In some embodiments, such as Figure 16 As shown, the overall frequency response data of the waveform generator and the overall frequency response data of the electrical connector can also be S-parameterized using an FPGA chip to obtain a first result. When determining the first overall characteristic data, the first overall characteristic data is selected from the first result based on the current center frequency and the current center bandwidth. That is, the overall frequency response data of the waveform generator and the overall frequency response data of the transmission link are first S-parameterized, and then the portion corresponding to the current center frequency and the current center bandwidth is selected from the superposition result as the first overall characteristic data.

[0102] In some embodiments, at least one electrical connector includes multiple electrical connectors, which are cascaded together. When at least one electrical connector includes multiple electrical connectors, such as... Figure 9 As shown, S2011, the first characteristic data and the second characteristic data are superimposed using S-parameters to obtain the first overall characteristic data, including the following steps:

[0103] S2011a. The frequency response characteristic data of each electrical connector is superimposed with the frequency response characteristic data corresponding to the preset output signal parameters by S-parameters to obtain the second overall characteristic data.

[0104] S2011b: The second overall characteristic data and the first characteristic data are superimposed using S-parameters to obtain the first overall characteristic data.

[0105] At least one electrical connector may be multiple electrical connectors, and the overall frequency response characteristic data of the transmission link is the overall frequency response characteristic data of all electrical connectors. When determining the first overall characteristic data, the FPGA chip can select the corresponding frequency response characteristic data from the overall frequency response characteristic data of each electrical connector based on the current center frequency and current center bandwidth. Then, the corresponding frequency response characteristic data from the overall frequency response characteristic data of each electrical connector selected based on the current center frequency and current center bandwidth are superimposed using S-parameters to obtain the second overall characteristic data. Finally, the second overall characteristic data and the first characteristic data are superimposed using S-parameters to calculate the first overall characteristic data, and a new compensation coefficient is further calculated based on the first overall characteristic data.

[0106] like Figure 16 As shown, S-parameter superposition can be performed first, and then the portion corresponding to the current center frequency and current center bandwidth can be selected from the superposition result as the first overall characteristic data. Specifically, the overall frequency response characteristic data of each electrical connector in multiple electrical connectors can be superimposed with S-parameters. Then, the S-parameter superposition result of the overall frequency response characteristic data of each electrical connector can be superimposed with the overall frequency response characteristic data of the waveform generator to obtain the second result. Further, the corresponding portion is selected from the second result as the first overall characteristic data based on the current center frequency and current center bandwidth.

[0107] In one specific embodiment, two electrical connectors are provided, and the frequency response characteristics of the two electrical connectors are respectively... and .

[0108] .

[0109] .

[0110] The overall frequency response characteristics of the RF channel of the waveform generator's output signal (the overall frequency response characteristics of the waveform generator) are as follows: .

[0111] When determining the first overall characteristic data, first... and After superimposing the S-parameters, the overall frequency response characteristics of the external connector, i.e., the overall frequency response characteristics of the transmission link, can be obtained. The overall frequency response characteristics of the transmission link are: .

[0112] Then, the overall frequency response characteristics of the transmission link and the overall frequency response characteristics of the waveform generator are superimposed using S-parameters to obtain the second result: The second result is the overall frequency response characteristic data from the digital-to-analog converter in the waveform generator to the end of the transmission link. When the waveform generator generates a digital baseband signal, it can select the corresponding part from the second result as the first overall characteristic data based on the current center frequency and the current center bandwidth. The current compensation coefficient can be calculated using the first overall characteristic data. When calculating the current compensation coefficient, the coefficients of the FIR filter, i.e., the current compensation coefficients, can be obtained by performing an IDFT (Inverse Discrete Fourier Transform) on the first overall characteristic data. In addition, windowing and smoothing processing can be performed, which will not be elaborated on here.

[0113] In some embodiments, such as Figure 10 , Figure 11 , Figure 16As shown, flatness compensation is performed on the digital baseband signal generated by the waveform generator according to the current compensation coefficient, followed by:

[0114] S400, in response to the first operation, acquire the signal generation parameters of the waveform generator, the first operation being used to enable the mode without absolute power compensation;

[0115] S500, Determine the current first power compensation value corresponding to the signal generation parameters;

[0116] S600: Perform power compensation on the digital baseband signal based on the current first power compensation value.

[0117] or;

[0118] S700, in response to the second operation, acquires the signal generation parameters of the waveform generator, the second operation being used to enable the absolute power compensation mode;

[0119] S800, Determine the current second power compensation value corresponding to the signal generation parameters;

[0120] S900: Perform power compensation on the digital baseband signal based on the current second power compensation value.

[0121] In some embodiments, when performing power compensation on the digital baseband signal, absolute power compensation or non-absolute power compensation can be performed. The power compensation mode can be switched via a first operation or a second operation through the operation panel. When performing the first operation, the mode without absolute power compensation is enabled, and non-absolute power compensation is performed on the digital baseband signal; when performing the second operation, the mode with absolute power compensation is enabled, and absolute power compensation is performed on the digital baseband signal.

[0122] In some embodiments, the signal generation parameters may include the signal sampling rate. In response to the first operation, the FPGA chip acquires the current signal sampling rate of the waveform generator, determines a corresponding current first power compensation value based on the acquired current signal sampling rate, and further performs power compensation on the digital baseband signal based on the current first power compensation value. In response to the second operation, the FPGA chip acquires the current signal sampling rate of the waveform generator, determines a corresponding current second power compensation value based on the acquired current signal sampling rate, and further performs power compensation on the digital baseband signal based on the current second power compensation value.

[0123] Therefore, this signal quality improvement method can also perform power compensation on digital baseband signals, avoiding the impact of power attenuation on the accuracy of the output signal of the device under test. Furthermore, it can compensate for power attenuation caused only by the waveform generator, or for power attenuation caused by both the waveform generator and the transmission link, thus improving flexibility. Specifically, when performing power compensation, it is assumed that the output signal power of the signal source at a certain frequency is... The power value is set to Then the power compensation range is .

[0124] In some embodiments, such as Figure 11 As shown, S500 determines the current first power compensation value corresponding to the signal generation parameters, including:

[0125] S501. Determine whether to update the current first power compensation value based on the signal generation parameters.

[0126] In some embodiments, the signal generation parameters may include the signal sampling rate. When performing power compensation using the current first power compensation value, the FPGA chip can compare the acquired current signal sampling frequency with the historically set signal sampling rate. If the current signal sampling frequency changes compared to the historically set signal sampling rate, the current first power compensation value needs to be recalculated and stored; otherwise, the previously stored historical current first power compensation value can be used as the current first power compensation value. The recalculation of the current first power compensation value is based at least on the first characteristic data to determine the new first power compensation value. The historically set signal sampling rate refers to the signal sampling rate set when the digital baseband signal was last generated.

[0127] In some embodiments, such as Figure 13 As shown, S800 determines the current second power compensation value corresponding to the signal generation parameters, including:

[0128] S801. Determine whether to update the current second power compensation value based on the signal generation parameters.

[0129] Similarly, when performing power compensation using the current second power compensation value, the FPGA chip can compare the acquired current signal sampling frequency with the historically set signal sampling rate. If the current signal sampling frequency changes compared to the historically set signal sampling rate, the current second power compensation value needs to be recalculated and stored. Conversely, the previously stored historical second power compensation value can be used as the current second power compensation value. The recalculation of the current second power compensation value is based at least on the first characteristic data and the second characteristic data to determine the new second power compensation value.

[0130] In some embodiments, the first characteristic data is the frequency response characteristic data in the overall frequency response characteristic data of the waveform generator corresponding to the signal generation parameters; the second characteristic data is the frequency response characteristic data corresponding to the signal generation parameters in the overall frequency response characteristic data of the transmission link.

[0131] In other words, different signal sampling rates correspond to different frequency response characteristic data. The FPGA chip can select frequency response characteristic data corresponding to the current signal sampling rate from the overall frequency response characteristic data of the waveform generator, i.e., the first characteristic data; it can also select frequency response characteristic data corresponding to the current signal sampling rate from the overall frequency response characteristic data of the transmission link, i.e., the second characteristic data. The specific details of the overall frequency response characteristic data of the waveform generator and the overall frequency response characteristic data of the transmission link can be found in the above description and will not be elaborated upon here.

[0132] In some embodiments, such as Figure 12 As shown, a new first power compensation value is determined based at least on the first characteristic data, including:

[0133] S5011. Calculate and determine a new first power compensation value based on the baseband signal power spectrum and first characteristic data of the waveform generator.

[0134] In some embodiments, when power calibrating the waveform generator, the power spectrum of the digital baseband signal corresponding to the baseband data input by the user through the operation panel is calculated: .

[0135] When absolute power compensation mode is not required, based on Power compensation is performed based on the first characteristic data; in absolute power compensation mode, based on Power compensation is performed using the second characteristic data.

[0136] The digital baseband signal generated by the waveform generator is in complex form, specifically in the form I+jQ, and its amplitude is... Performing a Fast Fourier Transform (FFT) on the entire digital baseband signal yields a first array of complex numbers. Squaring the amplitude of this first array produces a second array, which represents the power spectrum of the digital baseband signal. Assuming the current center frequency of the waveform generator is Freq and the current center bandwidth is BW, the output signal of the waveform generator will have an amplitude range of [Freq-BW / 2, Freq+BW / 2].

[0137] The frequency response data is also in complex form. The frequency response data corresponding to [Freq-BW / 2, Freq+BW / 2] is taken from the overall frequency response data of the waveform generator; this is the first characteristic data. The amplitude of the first characteristic data is normalized to its maximum value, and then multiplied by the complex number corresponding to the second array to obtain the third array after weighting the power spectrum of the digital baseband signal.

[0138] The frequency response characteristic data corresponding to [Freq-BW / 2, Freq+BW / 2] is taken from the overall frequency response characteristic data of the transmission link, that is, the second characteristic data. The first characteristic data and the second characteristic data are superimposed by S-parameters to obtain the first overall characteristic data. The amplitude of the first overall characteristic data is normalized according to the maximum value, and multiplied with the complex number corresponding to the second array to obtain the fourth array after weighting the power spectrum of the digital baseband signal.

[0139] The average of the sums of the second array is calculated to obtain the average value b; the average of the sums of the third array is calculated to obtain the average value c; and the average of the sums of the fourth array is calculated to obtain the average value d. In the absence of absolute power compensation mode, the current first power compensation value is 10log(c / b); in the absolute power compensation mode, the current second power compensation value is 10log(d / b).

[0140] In some embodiments, such as Figure 14 As shown, a new second power compensation value is determined based at least on the first characteristic data and the second characteristic data, including:

[0141] S8011. The first characteristic data and the second characteristic data are superimposed with S-parameters to obtain the first overall characteristic data;

[0142] S8012. Calculate the new second power compensation value based on the first overall characteristic data and the baseband signal power spectrum of the waveform generator.

[0143] In some embodiments, such as Figure 15 As shown, the transmission link includes at least one electrical connector, and the overall frequency response characteristic data of the transmission link includes the frequency response characteristic data of each electrical connector; when multiple electrical connectors are provided, the first characteristic data and the second characteristic data are superimposed using S-parameters to obtain the first overall characteristic data, including:

[0144] S8011a. The frequency response characteristic data corresponding to the preset output signal parameters in the overall frequency response characteristic data of the transmission link are superimposed with S-parameters to obtain the second overall characteristic data.

[0145] S8011b: The second overall characteristic data and the first characteristic data are superimposed using S-parameters to obtain the first overall characteristic data. For details, please refer to the process of determining the first overall characteristic data when setting multiple electrical connectors during flatness compensation; it will not be elaborated further here.

[0146] In some embodiments, the waveform generator can be any waveform generator, vector signal source, etc., capable of generating vector signals.

[0147] In some embodiments, the device under test can be a multi-port device such as a filter, transmission line amplifier, attenuator, matrix switch, etc.

[0148] In some embodiments, this application also provides a waveform generator, including:

[0149] At least one processor;

[0150] and memory that is communicatively connected to at least one processor;

[0151] The memory stores instructions executable by at least one processor. These instructions are executed by the at least one processor to enable it to perform the aforementioned signal quality improvement method. Specific details are provided in a particular embodiment of the signal quality improvement method, and will not be elaborated further here.

[0152] The above examples illustrate the present invention only to aid in understanding it and are not intended to limit the scope of the invention. Those skilled in the art can make various simple deductions, modifications, or substitutions based on the principles of this invention.

Claims

1. A signal quality improvement method, applied to a waveform generator that generates vector signals, characterized in that, The waveform generator is configured to connect to the device under test via a transmission link, and the signal quality improvement method includes: Obtain the preset output signal parameters of the waveform generator; Determine the current compensation coefficient corresponding to the preset output signal parameters; The digital baseband signal generated by the waveform generator is flattened according to the current compensation coefficient. The current compensation coefficient makes the frequency response characteristics of the signal output by the waveform generator after compensation present an opposite state to the frequency response characteristics of the transmission link, so as to improve the spectral flatness of the signal output by the waveform generator after passing through the transmission link. Determining the current compensation coefficient corresponding to the preset output signal parameters includes: Based on the preset output signal parameters, it is determined whether to update the current compensation coefficient. If yes, a new compensation coefficient is determined based on the first characteristic data and the second characteristic data, and the current compensation coefficient is updated to the new compensation coefficient and stored. If no, the previously stored historical current compensation coefficient in the waveform generator is used as the current compensation coefficient. The first characteristic data is the frequency response characteristic data in the overall frequency response characteristic data of the waveform generator corresponding to the preset output signal parameters. The second characteristic data is the frequency response characteristic data corresponding to the preset output signal parameters in the overall frequency response characteristic data of the transmission link.

2. The signal quality improvement method as described in claim 1, characterized in that, The preset output signal parameters include at least the current center frequency and current signal bandwidth set by the waveform generator; the step of determining whether to update the current compensation coefficient based on the preset output signal parameters includes: When the current center frequency of the waveform generator changes compared to the historically set center frequency and / or the current signal bandwidth of the waveform generator changes compared to the historically set signal bandwidth, the current compensation coefficient is updated. When the current center frequency of the waveform generator has not changed compared to the historically set center frequency and the current signal bandwidth of the waveform generator has not changed compared to the historically set signal bandwidth, the historical current compensation coefficient is the current compensation coefficient.

3. The signal quality improvement method as described in claim 1, characterized in that, The determination of the new compensation coefficient based on the first characteristic data and the second characteristic data includes: The first characteristic data and the second characteristic data are superimposed with S-parameters to obtain the first overall characteristic data; Calculate the new compensation coefficient based on the first overall characteristic data.

4. The signal quality improvement method as described in claim 3, characterized in that, The transmission link includes at least one electrical connector, and the overall frequency response characteristic data of the transmission link includes the frequency response characteristic data of each electrical connector; when multiple electrical connectors are provided, the step of superimposing the first characteristic data and the second characteristic data using S-parameters to obtain the first overall characteristic data includes: The frequency response characteristic data of each electrical connector is superimposed with the frequency response characteristic data corresponding to the preset output signal parameters by S-parameters to obtain the second overall characteristic data. The second overall characteristic data and the first characteristic data are superimposed using S-parameters to obtain the first overall characteristic data.

5. The signal quality improvement method as described in claim 1, characterized in that, The step of performing flatness compensation on the digital baseband signal generated by the waveform generator according to the current compensation coefficient further includes: In response to the first operation, the signal generation parameters of the waveform generator are obtained, wherein the first operation is used to enable the mode without absolute power compensation. Determine the current first power compensation value corresponding to the signal generation parameters; The digital baseband signal is power compensated according to the current first power compensation value; or; In response to the second operation, the signal generation parameters of the waveform generator are obtained, and the second operation is used to enable the absolute power compensation mode. Determine the current second power compensation value corresponding to the signal generation parameters; The digital baseband signal is power compensated according to the current second power compensation value.

6. The signal quality improvement method as described in claim 5, characterized in that, Determining the current first power compensation value corresponding to the signal generation parameters includes: Based on the signal generation parameters, determine whether to update the current first power compensation value; if yes, determine a new first power compensation value based at least on the first characteristic data, and update the current first power compensation value to the new first power compensation value; if no, use the previously stored historical current first power compensation value in the waveform generator as the current first power compensation value and store it. or; Based on the signal generation parameters, determine whether to update the current second power compensation value; if yes, determine a new second power compensation value based at least on the first characteristic data and the second characteristic data, update the current second power compensation value to the new second power compensation value, and store it; if no, use the historical current second power compensation value stored in the waveform generator at the previous moment as the current second power compensation value. Wherein, the first characteristic data is the frequency response characteristic data in the overall frequency response characteristic data of the waveform generator corresponding to the signal generation parameters; the second characteristic data is the frequency response characteristic data corresponding to the signal generation parameters in the overall frequency response characteristic data of the transmission link.

7. The signal quality improvement method as described in claim 6, characterized in that, The signal generation parameters include at least the signal sampling rate; the step of determining whether to update the current first power compensation value based on the signal generation parameters includes: When the current signal sampling rate of the waveform generator changes compared to the historically set signal sampling rate, the current first power compensation value is updated. When the current signal sampling rate of the waveform generator has not changed compared with the historically set signal sampling rate, the historical current first power compensation value is the current first power compensation value. The step of determining whether to update the current second power compensation value based on the signal generation parameters includes: When the current signal sampling rate of the waveform generator changes compared to the historically set signal sampling rate, the current second power compensation value is updated; When the current signal sampling rate of the waveform generator has not changed compared with the historically set signal sampling rate, the historical current second power compensation value is the current second power compensation value.

8. The signal quality improvement method as described in claim 6 or 7, characterized in that, The determination of the new first power compensation value based at least on the first characteristic data includes: The new first power compensation value is calculated and determined based on the baseband signal power spectrum of the waveform generator and the first characteristic data.

9. The signal quality improvement method as described in claim 6 or 7, characterized in that, The determination of the new second power compensation value based at least on the first characteristic data and the second characteristic data includes: The first characteristic data and the second characteristic data are superimposed with S-parameters to obtain the first overall characteristic data; The new second power compensation value is calculated based on the first overall characteristic data and the baseband signal power spectrum of the waveform generator.

10. The signal quality improvement method as described in claim 9, characterized in that, The transmission link includes at least one electrical connector, and the overall frequency response characteristic data of the transmission link includes the frequency response characteristic data of each electrical connector; when multiple electrical connectors are provided, the step of superimposing the first characteristic data and the second characteristic data using S-parameters to obtain the first overall characteristic data includes: The S-parameters are superimposed on the frequency response characteristic data corresponding to the preset output signal parameters in the overall frequency response characteristic data of the transmission link to obtain the second overall characteristic data. The second overall characteristic data and the first characteristic data are superimposed using S-parameters to obtain the first overall characteristic data.

11. A waveform generator, characterized in that, include: At least one processor; and a memory communicatively connected to the at least one processor; The memory stores instructions that can be executed by the at least one processor, which, when executed by the at least one processor, enables the at least one processor to perform the signal quality improvement method according to any one of claims 1-10.

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