A method for calibrating output power of a vector signal source and a vector signal source

Abstract

The application discloses a kind of vector signal source output power's scaling method and vector signal source, it is related to radio frequency signal generation and instrument measurement technical field.The vector signal source includes signal control module, radio frequency processing module, automatic level control module and processor.When bandwidth calibration signal is selected, signal control module uses first baseband gain coefficient to adjust bandwidth calibration signal and exports calibration signal;When vector baseband signal is selected, signal control module uses second baseband gain coefficient to adjust vector baseband signal and exports target vector baseband signal.Radio frequency processing module generates power calibration signal according to calibration signal, and generates target radio frequency vector signal according to target vector baseband signal.When bandwidth calibration signal is selected, automatic level control module generates calibration parameter in closed loop state according to power calibration signal;When vector baseband signal is selected, automatic level control module exports vector signal in open loop state according to calibration parameter.

Description

Technical Field

[0001] This application relates to the field of radio frequency signal generation and instrument measurement technology, specifically to a calibration method for the output power of a vector signal source and a vector signal source. Background Technology

[0002] To achieve high-precision and high-stability output power, radio frequency (RF) signal sources typically employ automatic level control loop technology. This technology dynamically adjusts the link gain by real-time detection of the output signal amplitude to maintain stable RF output power. Vector signal sources, as a type of RF signal source, usually have a wider bandwidth in their output signal, thus placing even higher demands on power control precision.

[0003] Most existing power calibration methods for vector signal sources are based on closed-loop control of signal power by the RF channel. However, the response of the RF channel to signals of different bandwidths varies significantly: narrowband or single-tone signals are only affected by the frequency response within a very small bandwidth range, while wideband vector signals are affected by the combined frequency response of the entire channel. Because traditional power calibration methods often do not fully consider the frequency response characteristics of the RF channel within its bandwidth range, deviations can easily occur between the actual power and the desired set value when outputting ultra-wideband vector signals.

[0004] On the other hand, in order to improve power accuracy, there is also an attempt to directly track the bandwidth vector signal by increasing the bandwidth of the power control loop. However, high-bandwidth loops often place more stringent requirements on the linearity, noise performance, and loop stability of the RF link, and are difficult to be compatible with multiple signals. The response time is also difficult to meet the needs of rapid switching of vector signal sources, so they are not suitable for vector signal sources in practical engineering.

[0005] For the reasons mentioned above, existing technologies generally suffer from insufficient accuracy when processing the output power of ultra-wideband vector signals. Especially with further increases in signal bandwidth, the influence of the RF channel's frequency response becomes increasingly significant, and current power calibration procedures often fail to incorporate the bandwidth frequency characteristics of the RF channel into the calibration process, leading to large output power errors. Therefore, it is necessary to propose a new calibration method for vector signal sources to effectively compensate for the amplitude response of the RF channel within its bandwidth range, achieving high-precision control of the output power of ultra-wideband signals. Summary of the Invention

[0006] The main technical problem addressed by this application is to provide a calibration method and vector signal source that incorporates the frequency response of the radio frequency channel into the vector signal calibration process and improves the accuracy of the output power of ultra-wideband vector signals.

[0007] According to the first aspect, one embodiment provides a vector signal source, including a digital signal processing module, a radio frequency processing module, an automatic level control module, and a processor;

[0008] The digital signal processing module includes a calibration signal generator, a vector signal generator, and a signal control module;

[0009] The calibration signal generator is used to generate a preset bandwidth calibration signal;

[0010] The vector signal generator is used to acquire the vector waveform data to be played and to generate a vector baseband signal based on the vector waveform data to be played.

[0011] The signal control module is used to select the bandwidth calibration signal and the vector baseband signal; when the bandwidth calibration signal is selected, the signal control module adjusts the bandwidth calibration signal using a first baseband gain coefficient and outputs a calibration signal for power calibration; when the vector baseband signal is selected, the signal control module adjusts the vector baseband signal using a second baseband gain coefficient and outputs a target vector baseband signal.

[0012] The radio frequency processing module is connected to the signal control module and is used to perform digital-to-analog conversion and radio frequency modulation on the calibration signal to generate a power calibration signal; and to perform digital-to-analog conversion and radio frequency modulation on the target vector baseband signal to generate a target radio frequency vector signal.

[0013] The automatic level control module is connected to the radio frequency processing module. When the bandwidth calibration signal is selected, the automatic level control module is in a closed-loop state, and in the closed-loop state, it performs power calibration according to the power calibration signal to obtain calibration parameters. When the vector baseband signal is selected, the automatic level control module is in an open-loop state, and in the open-loop state, it adjusts the gain of the automatic level control module according to the calibration parameters to output a vector signal.

[0014] The processor is used for:

[0015] The first baseband gain coefficient is obtained, and the first baseband gain coefficient is determined based on the power spectral density of the bandwidth calibration signal, the power spectral density of the vector waveform data to be played, and the frequency response of the radio frequency processing module.

[0016] Obtain the digital gain coefficient of the bandwidth calibration signal adjusted by the signal control module;

[0017] The second baseband gain coefficient is determined based on the digital gain coefficient and the first baseband gain coefficient;

[0018] When the bandwidth calibration signal is selected, the first baseband gain coefficient is configured to the signal control module; when the vector baseband signal is selected, the second baseband gain coefficient is configured to the signal control module.

[0019] In one embodiment, the power spectral density of the bandwidth calibration signal and the power spectral density of the vector waveform data to be played are obtained in the following manner:

[0020] Obtain the sampling point sequence of the bandwidth calibration signal and the sampling point sequence of the vector waveform data to be played;

[0021] Fourier transforms are performed on the sampling point sequence of the bandwidth calibration signal and the sampling point sequence of the vector waveform data to be played, respectively, to determine the frequency point sequence of the bandwidth calibration signal and the frequency point sequence of the vector waveform data to be played.

[0022] The power spectral density of the bandwidth calibration signal is determined based on the frequency point sequence of the bandwidth calibration signal and the number of transformation points of the Fourier transform.

[0023] The power spectral density of the vector waveform data to be played is determined based on the frequency point sequence of the vector waveform data to be played and the number of transformation points of the Fourier transform.

[0024] In one embodiment, when the number of transformation points of the Fourier transform is less than the number of sampling points of the vector waveform data to be played, the vector waveform data to be played is segmented so that the number of sampling points of each segment of the vector waveform data to be played is equal to the number of transformation points of the Fourier transform.

[0025] In one embodiment, the bandwidth calibration signal includes a single-tone signal and a wideband signal;

[0026] When the bandwidth calibration signal is a single-tone signal, the frequency response of the radio frequency processing module includes the frequency response of the single-tone signal in the radio frequency processing module and the frequency response of the vector waveform data to be played in the radio frequency processing module.

[0027] When the bandwidth calibration signal is a wideband signal, the frequency response of the radio frequency processing module includes the frequency response of the wideband signal in the radio frequency processing module and the frequency response of the vector waveform data to be played in the radio frequency processing module.

[0028] The frequency response of the single-tone signal in the radio frequency processing module is the frequency response value of the radio frequency processing module at a single frequency point in the single-tone signal.

[0029] The frequency response of the broadband signal in the radio frequency processing module is the set of frequency response values ​​of the radio frequency processing module at multiple frequency points in the broadband signal.

[0030] The frequency response of the vector waveform data to be played in the radio frequency processing module is a sequence of the frequency response values ​​of the radio frequency processing module within the bandwidth occupied by the vector waveform data to be played.

[0031] In one embodiment, the frequency response of the radio frequency processing module is obtained in the following manner:

[0032] The vector signal source generates a calibration signal of a preset frequency and outputs it to the test equipment connected to the vector signal source.

[0033] Acquire the sampling signal obtained by the test equipment sampling the calibration signal;

[0034] The frequency response of the radio frequency processing module is determined based on the sampled signal and the calibration signal.

[0035] In one embodiment, when the number of sampling points of the sampled signal output by the test device is greater than the number of transformation points of the Fourier transform, the number of transformation points of the Fourier transform is interpolated so that the number of sampling points of the sampled signal is equal to the number of transformation points of the Fourier transform; when the number of sampling points of the sampled signal output by the test device is less than the number of transformation points of the Fourier transform, the number of transformation points of the Fourier transform is decimated so that the number of sampling points of the sampled signal is equal to the number of transformation points of the Fourier transform.

[0036] In one embodiment, obtaining the digital gain coefficient for adjusting the bandwidth calibration signal by the signal control module includes:

[0037] Obtain the sampling point sequence of the bandwidth calibration signal;

[0038] Amplitude detection is performed on the sampling point sequence of the bandwidth calibration signal;

[0039] The sampling point sequence of the bandwidth calibration signal is normalized according to the amplitude detection result, and the gain value required for the digital gain coefficient of the bandwidth calibration signal to reach the preset set value is taken as the digital gain coefficient.

[0040] In one embodiment, determining the second baseband gain coefficient based on the digital gain coefficient and the first baseband gain coefficient includes:

[0041] The digital gain coefficient divided by the first baseband gain coefficient is the second baseband gain coefficient.

[0042] In one embodiment, the vector signal source further includes a local oscillator, the signal control module includes a selector and a gainer connected in sequence, and the radio frequency processing module includes a digital-to-analog converter and a modulator connected in sequence.

[0043] The input of the selector can be selectively connected to the output of the calibration signal generator and the vector signal generator. The output of the selector is connected to the input of the gain unit. The output of the gain unit is connected to the input of the digital-to-analog converter. The input of the modulator is connected to the output of the digital-to-analog converter and the output of the local oscillator. The output of the modulator is connected to the input of the automatic level control module. The digital-to-analog converter is used to convert the digital quantity of the calibration signal into the analog quantity of the calibration signal, and to convert the digital quantity of the target vector baseband signal into the analog quantity of the target vector baseband signal. The modulator receives the analog quantity of the calibration signal or the analog quantity of the target vector baseband signal from the digital-to-analog converter, and mixes it with the local oscillator signal output from the local oscillator to obtain a power calibration signal modulated to the radio frequency band and a target radio frequency vector signal, which are then output from the radio frequency output of the vector signal source through the automatic control module.

[0044] In one embodiment, the vector signal source further includes at least one filter connected between the output of the gainer and the input of the digital-to-analog converter, wherein the first baseband gain coefficient is determined based on the power spectral density of the bandwidth calibration signal, the power spectral density of the vector waveform data to be played, the frequency response of the RF processing module, and the frequency response of each filter; and / or, the vector signal source further includes at least one RF device connected between the output of the automatic level control module and the RF output, wherein the first baseband gain coefficient is determined based on the power spectral density of the bandwidth calibration signal, the power spectral density of the vector waveform data to be played, the frequency response of the RF processing module, the frequency response of each filter, and the frequency response of each RF device.

[0045] According to a second aspect, one embodiment provides a method for calibrating the output power of a vector signal source. The vector signal source includes a calibration signal generator, a vector signal generator, a signal control module, a radio frequency processing module, and an automatic level control module. The calibration signal generator is used to generate a preset bandwidth calibration signal. The vector signal generator is used to acquire vector waveform data to be played and generate a vector baseband signal based on the vector waveform data. The radio frequency processing module is used to acquire a calibration signal corresponding to the bandwidth calibration signal and perform digital-to-analog conversion and radio frequency modulation on the calibration signal to generate a power calibration signal. It is also used to acquire a target vector baseband signal corresponding to the vector baseband signal and perform digital-to-analog conversion and radio frequency modulation on the target vector baseband signal to generate a target radio frequency vector signal. The automatic level control module is used to perform power calibration based on the power calibration signal to obtain calibration parameters and adjust the gain of the automatic level control module based on the calibration parameters to output a vector signal.

[0046] The calibration method for the output power of the vector signal source includes:

[0047] Obtain the power spectral density of the vector waveform data to be played;

[0048] Obtain the power spectral density of the bandwidth-calibrated signal;

[0049] Obtain the frequency response of the radio frequency processing module;

[0050] The first baseband gain coefficient is determined based on the power spectral density of the bandwidth calibration signal, the power spectral density of the vector waveform data to be played, and the frequency response of the radio frequency processing module.

[0051] When the bandwidth calibration signal is selected, the first baseband gain coefficient is configured to the signal control module. The signal control module adjusts the bandwidth calibration signal using the first baseband gain coefficient and outputs the calibration signal for power calibration.

[0052] Obtain the digital gain coefficient of the bandwidth calibration signal adjusted by the signal control module;

[0053] The second baseband gain coefficient is determined based on the digital gain coefficient and the first baseband gain coefficient.

[0054] When the vector baseband signal is selected, the second baseband gain coefficient is configured to the signal control module. The signal control module adjusts the vector baseband signal using the second baseband gain coefficient and outputs the target vector baseband signal.

[0055] In one embodiment, the power spectral density of the bandwidth calibration signal and the power spectral density of the vector waveform data to be played are obtained in the following manner:

[0056] Obtain the sampling point sequence of the bandwidth calibration signal and the sampling point sequence of the vector waveform data to be played;

[0057] Fourier transforms are performed on the sampling point sequence of the bandwidth calibration signal and the sampling point sequence of the vector waveform data to be played, respectively, to determine the frequency point sequence of the bandwidth calibration signal and the frequency point sequence of the vector waveform data to be played.

[0058] The power spectral density of the bandwidth calibration signal is determined based on the frequency amplitude sequence of the bandwidth calibration signal and the number of transform points of the Fourier transform.

[0059] The power spectral density of the vector waveform data to be played is determined based on the frequency point sequence of the vector waveform data to be played and the number of transformation points of the Fourier transform.

[0060] In one embodiment, when the number of transformation points of the Fourier transform is less than the number of sampling points of the vector waveform data to be played, the vector waveform data to be played is segmented so that the number of sampling points of each segment of the vector waveform data to be played is equal to the number of transformation points of the Fourier transform.

[0061] In one embodiment, determining the second baseband gain coefficient based on the digital gain coefficient and the first baseband gain coefficient includes:

[0062] The digital gain coefficient divided by the first baseband gain coefficient is the second baseband gain coefficient.

[0063] In one embodiment, obtaining the digital gain coefficient for adjusting the bandwidth calibration signal by the signal control module includes:

[0064] Obtain the sampling point sequence of the bandwidth calibration signal;

[0065] Amplitude detection is performed on the sampling point sequence of the bandwidth calibration signal;

[0066] The sampling point sequence of the bandwidth calibration signal is normalized according to the amplitude detection result, and the gain value required for the digital gain coefficient of the bandwidth calibration signal to reach the preset set value is taken as the digital gain coefficient.

[0067] In one embodiment, the calibration method for the output power of the vector signal source further includes:

[0068] Determine whether the radio frequency of the radio frequency processing module has been switched. If so, read the frequency response corresponding to the radio frequency of the radio frequency processing module to update the frequency response of the radio frequency processing module, and calculate the first baseband gain coefficient based on the updated frequency response of the radio frequency processing module.

[0069] According to a third aspect, one embodiment provides a computer-readable storage medium storing a computer program that can be executed by a processor to implement the methods described in any of the above embodiments.

[0070] A calibration method for the output power of a vector signal source and a vector signal source according to the above embodiments aim to solve the problem of inaccurate power output of existing vector signal sources when outputting ultra-wideband vector signals. The vector signal source includes a digital signal processing module, a radio frequency (RF) processing module, an automatic level control module, and a processor. The digital signal processing module includes a calibration signal generator, a vector signal generator, and a signal control module. The digital signal processing module generates a bandwidth calibration signal and a vector baseband signal to be played, and selects different signal paths. The RF processing module performs digital-to-analog conversion and RF modulation on the calibration signal and the vector baseband signal, respectively, and outputs corresponding RF signals. The automatic level control module is in a closed-loop state during the calibration stage to achieve power calibration, and in an open-loop state during the vector signal output stage to output a stable vector signal. The processor calculates and configures the baseband gain coefficient to achieve power consistency between the wideband calibration signal and the vector signal after the RF channel.

[0071] The processor first determines the first baseband gain coefficient based on the power spectral density of the signal and the frequency response of the RF channel, and then further calculates the second baseband gain coefficient for the vector waveform data to be played, in conjunction with the digital gain coefficient. When a bandwidth calibration signal is selected, the signal control module outputs a calibration signal using the first baseband gain coefficient, and the automatic level control module performs power calibration on this calibration signal in closed-loop mode to obtain calibration parameters. Subsequently, switching to the vector signal path, the signal control module outputs a vector baseband signal using the second baseband gain coefficient, and the automatic level control module outputs a precisely powered RF vector signal in open-loop mode based on the calibration parameters.

[0072] This application no longer uses a pure single-tone signal as the calibration basis. Instead, it uses a single-tone signal that takes into account the frequency response of the RF channel for power calibration, combined with a bandwidth calibration signal. This fundamentally avoids the power errors caused by the different RF channel responses of single-tone and broadband signals in traditional solutions. By calculating the first and second baseband gain coefficients, the bandwidth calibration signal and the vector waveform data to be played achieve the same power after passing through the RF processing module. This effectively compensates for the frequency response of the RF processing module, eliminating the need for additional calibration of the RF processing module and ensuring power consistency of the vector signal before and after the automatic level control module. Furthermore, through the above configuration, this application can still achieve high-precision vector signal power output even when the frequency response of the RF processing module is complex or the vector signal bandwidth is wide. Attached Figure Description

[0073] Figure 1 This is a schematic diagram of the overall structure of a vector signal source in one embodiment;

[0074] Figure 2 This is a schematic diagram of the unfolded structure of the digital signal processing module in a vector signal source in one embodiment;

[0075] Figure 3 This is a schematic diagram of the unfolded structure of the signal control module in a vector signal source in one embodiment;

[0076] Figure 4 This is a schematic diagram of the unfolded structure of the radio frequency processing module in a vector signal source in one embodiment;

[0077] Figure 5 This is a flowchart illustrating the overall process of a calibration method for the output power of a vector signal source executed by a processor in one embodiment.

[0078] Figure 6 This is a flowchart illustrating a method for determining the power spectral density of a bandwidth calibration signal and the power spectral density of the vector waveform data to be played, as described in one embodiment.

[0079] Figure 7 This is a flowchart illustrating a method for determining the frequency response of a radio frequency processing module in one embodiment.

[0080] Figure 8 This is a schematic diagram of a structure for calibrating the frequency response of a radio frequency processing module using a spectrum analyzer in one embodiment.

[0081] Figure 9 This is a schematic diagram of the structure of a vector signal source extension in one embodiment;

[0082] Figure 10This is a flowchart illustrating a method for calibrating the output power of a vector signal source in another embodiment. Detailed Implementation

[0083] The present application will now be described in further detail with reference to the accompanying drawings and specific embodiments. Similar elements in different embodiments are referred to by related similar element reference numerals. In the following embodiments, many details are described to facilitate a better understanding of the present 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 the present application are not shown or described in the specification. This is to avoid obscuring the core parts of the present 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.

[0084] 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 steps or actions in the method description can be rearranged 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.

[0085] 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).

[0086] In one embodiment, to facilitate understanding of the technical solution of this application, the following describes two commonly used power control methods in vector signal sources.

[0087] The first power calibration method: In this method, before the vector signal source actually outputs the vector signal, it first outputs a single-tone signal with the same power as the target vector signal. At this time, the automatic level control loop is in a closed-loop state. The loop detects the output power of the single-tone signal and adjusts the gain to stabilize the output power of the RF channel. Once the power is stable, the automatic level control loop is opened, and only then is the actual vector signal output.

[0088] The advantage of this method is that the automatic level control loop does not need to track the bandwidth signal, thus the requirements for loop bandwidth and device linearity are relatively low, making it simple to implement and providing good stability. However, because the response characteristics of the RF channel to single-tone signals and bandwidth vector signals are inconsistent—single-tone signals are only affected by the frequency response within a very narrow bandwidth range, while bandwidth vector signals are affected by the frequency response of the entire channel—the power calibrated by this method cannot accurately reflect the actual power of the bandwidth vector signal after passing through the RF channel, ultimately leading to a large deviation in output power.

[0089] The second power calibration method involves maintaining the automatic level control loop in a closed-loop state when outputting the vector signal, essentially using a high-bandwidth automatic level control loop to directly perform real-time power tracking of the vector signal. Theoretically, this method can achieve high power accuracy because it directly controls the target signal itself. However, in practical applications, the high-bandwidth automatic level control loop faces several challenges: it places higher demands on the linearity of the RF link, easily introduces noise amplification, reduces loop stability, and struggles to simultaneously adapt to various bandwidth modulation signals. Furthermore, the high-bandwidth loop has a long dynamic response time, which is detrimental to the performance of the vector signal source during signal switching or rapid amplitude changes. Therefore, this approach is difficult to implement on a large scale in practical vector signal sources.

[0090] In summary, neither of the two power calibration methods fully considers the true frequency response characteristics of the RF channel within its bandwidth, thus failing to ensure the output power accuracy of ultra-wideband vector signals. In particular, as the signal bandwidth continues to increase, the impact of differences in the amplitude response of the RF channel on power error becomes increasingly significant.

[0091] Therefore, this application proposes a calibration method for the output power of a vector signal source and a vector signal source, which can introduce the bandwidth frequency response characteristics of the radio frequency channel into the power calibration process of the vector signal, thereby significantly improving the accuracy of the output power of the ultra-wideband signal. The details are described below.

[0092] Please refer to Figure 1 In one embodiment, the vector signal source 2 includes a processor 21, a memory 22, a digital signal processing module 23, a radio frequency processing module 24, and an automatic level control module 25 (ALC).

[0093] In one embodiment, the processor 21 is used to manage the overall operation of the vector signal source 2 and read the vector waveform data to be played from the memory 22. The memory 22 can store the vector waveform data to be played, the calibration parameters of the vector signal, and the configuration data related to power calibration.

[0094] Please refer to Figure 2In one embodiment, the digital signal processing module 23 may be implemented by a field-programmable gate array (FPGA), which specifically includes a scaling signal generator 231, a vector signal generator 232, and a signal control module 233.

[0095] In one embodiment, a calibration signal generator 231 generates a preset bandwidth calibration signal for power calibration. The preset bandwidth calibration signal includes both single-tone signals and wideband signals. The wideband signal is designed to have a power spectral density that is the same as or very close to the vector waveform data to be played, ensuring that the frequency response of the bandwidth calibration signal in the radio frequency channel is highly consistent with that of the vector signal.

[0096] It should be noted that aligning the power spectral density of the bandwidth calibration signal with that of the vector waveform data to be played can accurately reflect the power attenuation characteristics of the vector signal in the RF channel. Wideband signals do not exhibit random characteristics, reducing the pressure on the automatic level control module 25 for rapid tracking and significantly lowering the requirements for the loop bandwidth and device linearity of the automatic level control module 25.

[0097] In one embodiment, a vector signal generator 232 is connected to a memory 22 to acquire vector waveform data to be played and generate a vector baseband signal based on the vector waveform data.

[0098] In one embodiment, in Figure 2 In the structure shown, the power of the vector baseband signal output by the vector signal generator 232 is denoted as Pwave1, and the power of the single-tone signal or wideband signal output by the calibration signal generator 231, i.e., the power of the bandwidth calibration signal, is denoted as Psin1. The power of the calibration signal output by the signal control module 233 for both types of signals is denoted as Psin2, and the power of the target vector baseband signal is Pwave2.

[0099] Please refer to Figure 3In one embodiment, the signal control module 233 includes a selector 2331 and a gainer 2332 connected in sequence. The input of the selector 2331 is selectively connected to the outputs of the calibration signal generator 231 and the vector signal generator 232. The output of the selector 2331 is connected to the input of the gainer 2332, and the output of the gainer 2332 serves as the output of the signal control module 233. The signal control module 233 is used to select between a bandwidth calibration signal and a vector baseband signal, and applies different baseband gain coefficients according to the selected signal. When the selector 2331 selects the bandwidth calibration signal, the signal control module 233 adjusts the bandwidth calibration signal using a first baseband gain coefficient and outputs a calibration signal for power calibration; when the selector 2331 selects the vector baseband signal, the signal control module 233 adjusts the vector baseband signal using a second baseband gain coefficient and outputs a target vector baseband signal.

[0100] In one embodiment, the radio frequency processing module 24 is connected to the signal control module 233 and is used to perform digital-to-analog conversion and radio frequency modulation on the calibration signal to generate a power calibration signal. It is also used to perform digital-to-analog conversion and radio frequency modulation on the target vector baseband signal to generate a target radio frequency vector signal.

[0101] Please refer to Figure 4 In one embodiment, the radio frequency (RF) processing module 24 includes a digital-to-analog converter (DAC) 241 and a modulator 242 connected in sequence. The RF processing module 24 also includes a local oscillator 243. The input terminal of the DAC 241 is connected to the output terminal of the gain unit 2332. The input terminal of the modulator 242 is connected to both the output terminal of the DAC 241 and the output terminal of the local oscillator 243. The output terminal of the modulator 242 serves as the output terminal of the RF processing module 24. The DAC 241 converts the digital quantity of the calibration signal into an analog quantity of the calibration signal, the power corresponding to the analog quantity of the calibration signal being denoted as Psin3. The DAC 241 also converts the digital quantity of the target vector baseband signal into an analog quantity of the target vector baseband signal, the power corresponding to the analog quantity of the target vector baseband signal being Pwave3. Modulator 242 receives the analog signal of the calibration signal or the analog signal of the target vector baseband signal from digital-to-analog converter 241, and mixes it with the local oscillator signal output from local oscillator source 243 to obtain a power calibration signal and a target RF vector signal modulated to the RF band. The power of the power calibration signal is denoted as Psin4, and the power of the target RF vector signal is denoted as Pwave4.

[0102] In one embodiment, the input terminal of the automatic level control module 25 is connected to the output terminal of the radio frequency processing module 24, and the output terminal of the automatic level control module 25 is connected to the radio frequency output terminal of the vector signal source 2. The automatic level control module 25 is used to control the output power of the final vector signal.

[0103] Specifically, when selector 2331 selects the bandwidth calibration signal, automatic level control module 25 is in closed-loop mode. Automatic level control module 25 adjusts the gain of the RF channel in real time by detecting the power calibration signal output by modulator 242, so that the RF output power (denoted as Psin5) of the output signal corresponding to the power calibration signal can be stabilized to the set target power. After the automatic level control module 25 operates in closed loop, it calculates and stores calibration parameters based on the RF output power in the stable state for power compensation of the vector signal.

[0104] When selector 2331 selects a vector baseband signal, automatic level control module 25 is in open-loop state. Automatic level control module 25 adjusts the gain of RF channel according to the acquired calibration parameters so that the power of the vector signal output at the final RF output terminal (i.e., Pwave5) reaches the set target power.

[0105] It should be noted that this application simplifies the RF channel to the digital-to-analog converter 241 and modulator 242 in the RF processing module 24. The actual RF channel is much more complex than the RF processing module 24, and may include various analog or RF devices such as RF amplifiers, variable attenuators, filters, and / or isolators, in addition to the digital-to-analog converter 241 and modulator 242. The frequency response characteristics of each device will also collectively affect the power distribution of the vector signal in the RF channel. However, regardless of the number and structure of the devices in the actual RF channel, in power calibration, the power of the power calibration signal passing through all the hardware of the RF channel in the RF processing module 24 and before entering the automatic level control module 25 is denoted as Psin4, and the power of the target RF vector signal is denoted as Pwave4.

[0106] In one embodiment, in the vector signal source 2, the automatic level control module 25 has a gain adjustment function for the output power of the radio frequency signal. Let the gain coefficient of the automatic level control module 25 for the signal power be α, then the radio frequency output power satisfies the following formula:

[0107] Pwave5 = α × Pwave4

[0108] Psin5=α×Psin4

[0109] Wherein, Pwave5 represents the power of the vector signal, α represents the gain coefficient of the automatic level control module 25, Pwave4 represents the power of the target RF vector signal, Psin5 represents the RF output power, and Psin4 represents the power of the power calibration signal.

[0110] In the user interface, the target power is set by inputting vector signal source 2, which is Psetting. Ideally, it should satisfy the following:

[0111] Pwave5=Psetting=α×Pwave4

[0112] This means that when outputting a vector signal, the automatic level control module 25 should ensure that the power of the vector signal matches the user-set target power. However, in traditional power calibration processes, power calibration is usually performed using a single-tone signal, i.e., through the following formula:

[0113] Psetting = Psin5 = α × Psin4

[0114] This enables the automatic level control module 25 to track the single-tone signal, ensuring that the RF output power of the single-tone signal reaches the set target power. The power of the output vector signal equals the RF output power of the single-tone signal only if Psin4 = Pwave4, i.e.:

[0115] Psin5= Pwave5=Psetting

[0116] In one embodiment, to achieve the above conditions, conventional methods typically control the scaling signal generator 231 and the vector signal generator 232 in the digital signal processing module 23, ensuring that the power of the output bandwidth scaling signal and the power of the vector baseband signal satisfy the following:

[0117] Pwave1 = Psin1

[0118] When the frequency response characteristics of a narrowband vector signal or RF channel are relatively ideal, Pwave4≈Psin4 can still be maintained after passing through modules such as gainer 2332, digital-to-analog converter 241, and modulator 242, thus achieving accurate power calibration. However, in ultra-wideband vector signal scenarios, the frequency response of the RF channel affects the overall power of the signal, causing the energy distribution of the vector signal to be affected by the frequency response, while single-tone signals are only affected by the single-point frequency response. Therefore, even if Pwave1=Psin1, it is difficult to guarantee that Psin4=Pwave4, resulting in a deviation between the power of the vector signal and the set target power, which cannot meet the requirements of high-precision control.

[0119] In one embodiment, the calibration method for the output power of the vector signal source 2 provided in this application independently adjusts the power Pwave1 of the vector baseband signal and the power Psin1 of the bandwidth calibration signal in the digital signal processing module 23. It does not require them to be equal, but rather uses an algorithm to ensure that the vector baseband signal and the bandwidth calibration signal satisfy Psin4 = Pwave4 after passing through the RF channel. That is, by adjusting the power of the single-tone signal used for calibration, and utilizing the different frequency response characteristics of the RF channel to the bandwidth calibration signal and the vector baseband signal, the bandwidth calibration signal and the vector baseband signal achieve consistent power before entering the automatic level control module 25. This ensures that after the gain of the automatic level control module 25, the RF output of the vector signal source 2 satisfies Pwave5 = Psetting.

[0120] Please refer to Figure 5 In one embodiment, to ensure that Psin4 = Pwave4, the processor 21 provided in this application executes a calibration method for the output power of the vector signal source 2, which specifically includes the following steps.

[0121] Step S110: Obtain the first baseband gain coefficient.

[0122] In one embodiment, the first baseband gain coefficient is determined based on the power spectral density of the bandwidth calibration signal, the power spectral density of the vector waveform data to be played, and the frequency response of the radio frequency processing module 24.

[0123] Please refer to Figure 6 In one embodiment, the method for determining the power spectral density of the bandwidth calibration signal and the power spectral density of the vector waveform data to be played includes the following steps.

[0124] Step S111: Obtain the sampling point sequence of the bandwidth calibration signal and the sampling point sequence of the vector waveform data to be played.

[0125] In one embodiment, to obtain the power spectral density of the bandwidth calibration signal and the power spectral density of the vector waveform data to be played, the sampling point sequences of the two types of signals in the digital baseband domain are first obtained respectively. The sampling point sequence of the bandwidth calibration signal is denoted as s[n], and the sampling point sequence of the vector waveform data to be played is denoted as x[n], where n=0, 1, 2, ..., Nsamples-1, and Nsamples is the number of sampling points of the bandwidth calibration signal and the vector waveform data to be played.

[0126] Step S113: Perform Fourier transform on the sampling point sequence of the bandwidth calibration signal and the sampling point sequence of the vector waveform data to be played, respectively, to determine the frequency point sequence of the bandwidth calibration signal and the frequency point sequence of the vector waveform data to be played.

[0127] In one embodiment, a Fourier transform is performed on the sampling point sequence of the bandwidth calibration signal to obtain the frequency point sequence S[n] of the corresponding bandwidth calibration signal. A Fourier transform is then performed on the sampling point sequence of the vector waveform data to be played to obtain the corresponding frequency point sequence X[n] of the vector waveform data to be played.

[0128] Step S115: Determine the power spectral density of the bandwidth calibration signal and the power spectral density of the vector waveform data to be played.

[0129] In one embodiment, the power spectral density of the vector waveform data to be played can be obtained from the Fourier transform result using the following formula:

[0130]

[0131] in, This represents the power spectral density of the vector waveform data to be played. This indicates the number of transformation points used in the Fourier transform.

[0132] In one embodiment, the power spectral density of the bandwidth-calibrated signal can be obtained from the Fourier transform result using the following formula:

[0133]

[0134] in, This represents the power spectral density of the bandwidth-calibrated signal. This indicates the number of transformation points used in the Fourier transform.

[0135] In one embodiment, according to Parseval's theorem, the power of the signal remains consistent in the time and frequency domains. Therefore, the total power of the signal can be obtained by summing the power spectral density over the frequency range of the Fourier transform. Thus:

[0136]

[0137]

[0138] It should be noted that if the bandwidth scaling signal samples a single-tone signal, the power spectral density of the single-tone signal requires further interpretation: the frequency domain energy of the single-tone signal is entirely concentrated at a certain frequency point n0, and the power spectral density at all other frequency points is zero. Therefore, the power spectral density of the single-tone signal is:

[0139]

[0140] in, Let n be the power spectral density of a single-tone signal at frequency point n0. This is a frequency point sequence of a single-tone signal at point n0. This indicates the number of transform points used in the Fourier transform. Since a single-tone signal has energy at only one frequency point, then:

[0141]

[0142] Furthermore, the power spectral density of both the bandwidth calibration signal and the power spectral density of the vector waveform data to be played are obtained by performing a Fourier transform on the sampling point sequence. In some cases, the number of sampling points Nsamples of the vector waveform data is greater than the number of transform points used in the Fourier transform. In this case, to ensure the correctness and consistency of the Fourier transform, it is necessary to segment the vector waveform data to be played. Specifically, the sampling point sequence of the vector waveform data to be played is sequentially truncated to a length of... The data segments are processed by treating each segment as an independent sequence and performing a Fourier transform on each segment. The power spectral density of the frequency point sequence obtained from the Fourier transform of each segment is calculated. The power spectral densities of all segments are summed and averaged to obtain the overall power spectral density of the vector waveform data to be played.

[0143] Please refer to Figure 7 In one embodiment, the method for determining the frequency response of the radio frequency processing module 24 includes the following steps.

[0144] Step S112: Determine the frequency response in the radio frequency processing module.

[0145] Please refer to Figure 8 In one embodiment, to accurately obtain the frequency response of the radio frequency processing module 24, a spectrum analyzer with sufficient intermediate frequency bandwidth is used as the test device. The vector signal source 2 and the spectrum analyzer are synchronized via a reference clock interface, ensuring they maintain a unified time and frequency reference. It should be noted that the reference clock is typically 10 MHz, but this embodiment is not limited to this frequency; any frequency that enables synchronization is acceptable.

[0146] In one embodiment, the RF output of vector signal source 2 is connected to the RF input of a spectrum analyzer via an RF cable. Vector signal source 2 outputs a preset calibration signal, which can be a variety of broadband sequences with good autocorrelation characteristics, such as binary phase shift keying (BPSK) modulation signals, Zadoff-Chu sequences, etc. These calibration signals have advantages such as amplitude stability, wide frequency domain coverage, and strong correlation, making them suitable for estimating RF channels.

[0147] In one embodiment, the spectrum analyzer samples the calibration signal to obtain a sampled signal. The sampled signal is then transmitted to a computer via a data interface. In the computer, the calibration signal and the sampled signal are correlated, inverted, and time-frequency aligned to calculate the frequency response of the radio frequency channel, reflecting the amplitude and phase characteristics of the radio frequency processing module 24 at different frequency points.

[0148] Step S114: Determine the frequency response of the bandwidth calibration signal in the RF processing module according to the different types of bandwidth calibration signals.

[0149] Step S116: Determine the frequency response of the vector waveform data to be played in the radio frequency processing module.

[0150] In one embodiment, the bandwidth calibration signal includes two types: single-tone signal and wideband signal. Depending on the type of bandwidth calibration signal, it is necessary to obtain the frequency response characteristics of different types of bandwidth calibration signals in the RF processing module 24, and combine this with the frequency response of the vector waveform data to be played in the RF processing module 24, to jointly calculate the first baseband gain coefficient.

[0151] In one embodiment, when the bandwidth calibration signal is a single-tone signal, since the single-tone signal contains only one frequency point, its frequency response in the RF processing module 24 can be expressed as the frequency response value of the RF processing module 24 at that single frequency point. Meanwhile, the vector waveform data to be played is typically a wideband signal, covering a continuous or discrete frequency bandwidth. Therefore, it is necessary to obtain the frequency response value sequence of the RF processing module 24 at all frequency points within the bandwidth occupied by the vector signal. In other words, under the calibration of the single-tone signal, the frequency response of the RF processing module 24 is jointly constituted by the single-point response value corresponding to the single-tone signal and the frequency response sequence of the vector waveform data to be played within the bandwidth.

[0152] In one embodiment, when the bandwidth calibration signal is a broadband signal, the broadband signal consists of multiple frequency points, and the amplitude of each frequency point can be precisely controlled to form a specific power spectral density distribution. In this case, the frequency response of the broadband signal in the RF processing module 24 is composed of the set of frequency response values ​​corresponding to its multiple frequency points. Simultaneously, it is still necessary to acquire the frequency response sequence of the vector waveform data to be played within its occupied bandwidth to reflect the attenuation characteristics of the RF channel at different spectral positions. Therefore, under the calibration of the broadband signal, the frequency response of the RF processing module 24 is jointly composed of the set of response values ​​at each frequency point of the broadband signal and the broadband frequency response sequence of the vector waveform data.

[0153] It should be noted that after acquiring the sampling sequence of the RF calibration signal through the test equipment, a Fourier transform needs to be performed on the sampled signal to calculate the frequency response of the RF processing module 24. Since the number of sampling points output by the test equipment may differ from the number of Fourier transform points used in the vector signal source 2 in this embodiment, the number of sampling points needs to be adjusted to ensure consistency in frequency domain analysis. When the number of sampling points in the sampled signal output by the test equipment is greater than the number of transform points in the Fourier transform, the sampling sequence is first decimated by deleting some sampling points to reduce the data volume, making the adjusted number of sampling points consistent with the number of transform points in the Fourier transform. Conversely, when the number of sampling points in the sampled signal output by the test equipment is less than the number of transform points in the Fourier transform, interpolation is performed by inserting sampling points between the sampling sequences to expand the number of sampling points in the sampled signal to be equal to the number of transform points in the Fourier transform. Through the above interpolation or decimation processing, it can be ensured that the sampled signal has a uniform number of points when performing the Fourier transform, thereby ensuring the comparability and consistency of the final frequency response under different test conditions.

[0154] Step S120: Obtain the digital gain coefficient of the bandwidth calibration signal adjusted by the signal control module.

[0155] In one embodiment, to determine the digital gain coefficient required for the signal control module 233 to adjust the bandwidth calibration signal, amplitude evaluation and normalization processing of the baseband sampling point sequence of the bandwidth calibration signal are required. Specifically, the sampling point sequence of the bandwidth calibration signal is first obtained from the calibration signal generator 231, and amplitude detection is performed on the sampling point sequence to obtain the current amplitude range or peak amplitude of the signal. Based on the amplitude detection result, the sampling point sequence is normalized so that the amplitude of the bandwidth calibration signal is adjusted to a preset standard amplitude level, i.e., normalized to 1. In this way, when the bandwidth calibration signal is in a normalized state, the digital gain coefficient can be determined according to the gain amount required for its actual amplitude to reach the set amplitude value.

[0156] It should be noted that the power calibration logic of this application requires the bandwidth calibration signal to maintain a uniform power reference under different test conditions. Therefore, regardless of whether the bandwidth calibration signal is in single-tone or wideband form, it must undergo the same normalization process to uniformly adjust its amplitude to the normalization value of 1. In this way, it is possible to ensure that the digital gain coefficient derived from the bandwidth calibration signal has a uniform reference standard, thereby ensuring that the calculated first baseband gain coefficient is accurate and effective, which is beneficial for achieving consistent power calibration results for different bandwidth calibration signals and target vector signals.

[0157] Step S130: Determine the second baseband gain coefficient.

[0158] In one embodiment, taking a single-tone signal as an example, in order to make the power of the vector signal before entering the automatic level control module 25 after the RF channel equal to the power of the single-tone signal used for calibration, so that the RF output consistent with the user-set power is achieved after the gain adjustment by the automatic level control module 25, it is necessary to determine the first baseband gain coefficient in the calibration process and the second baseband gain coefficient in the vector signal playback process. The first baseband gain coefficient has been clearly explained in the above steps, and here it will be derived and explained in conjunction with the RF channel frequency response and power spectral density.

[0159] In one embodiment, the second baseband gain coefficient corresponding to the vector waveform data to be played is set to β1, and its corresponding frequency response is... The frequency point sequence X[n] of the vector waveform data to be played, after passing through digital gain and RF channel, can be expressed in frequency domain form as follows:

[0160]

[0161] in, This represents the frequency point sequence of the vector waveform data to be played in the frequency domain, where β1 is the second baseband gain coefficient. The frequency response of the radio frequency processing module 24 corresponding to the vector waveform data to be played.

[0162] The RF power of the vector waveform data to be played before entering the automatic level control module 25 is:

[0163]

[0164] Where Pwave4 represents the power of the target RF vector signal, and β1 is the second baseband gain coefficient. This represents the power spectral density of the vector waveform data to be played. The frequency response of the radio frequency processing module 24 corresponding to the vector waveform data to be played.

[0165] In one embodiment, the digital gain coefficient corresponding to the single-tone signal is β2, and its corresponding frequency response is The power of the single-tone signal after passing through the radio frequency channel is:

[0166]

[0167] Where Psin4 represents the power of the power calibration signal, and β2 is the digital gain coefficient corresponding to the single-tone signal. Let n be the power spectral density of a single-tone signal at frequency point n0. This is the frequency response of the radio frequency processing module 24 corresponding to the single-tone signal.

[0168] To maintain the accuracy of the vector signal output outside the open loop of the automatic level control module 25, Psin4 = Pwave4 must be satisfied. Substituting the two formulas above, we get:

[0169]

[0170] Further analysis reveals:

[0171]

[0172] Where β is the first baseband gain coefficient, β1 is the second baseband gain coefficient, and β2 is the digital gain coefficient corresponding to the single-tone signal.

[0173] In the calculation process, if the digital gain coefficient β2 corresponding to the single-tone signal is set to 1, then:

[0174]

[0175] Therefore, the first baseband gain coefficient is determined in step S110, the digital gain coefficient is determined in step S120, and the digital gain coefficient is divided by the first baseband gain coefficient to obtain the second baseband gain coefficient.

[0176] Step S140: Configure the first baseband gain coefficient and the second baseband gain coefficient.

[0177] In one embodiment, when a bandwidth calibration signal is selected, a first baseband gain coefficient is configured to the signal control module 233; when a vector baseband signal is selected, a second baseband gain coefficient is configured to the signal control module 233. Thus, this application can achieve high-precision RF output power control even in situations with complex RF channel frequency response and wide vector signal bandwidth.

[0178] In summary, in the vector signal source 2 with the above basic structure, the determination of the first baseband gain coefficient depends only on the power spectral density of the bandwidth calibration signal, the power spectral density of the vector waveform data to be played, and the frequency response of the RF processing module 24. To illustrate the applicability of this application in more engineering application scenarios, this embodiment further extends the structure of the vector signal source 2, demonstrating that even when additional components are added to the digital link and RF link, the present invention can still achieve high-precision broadband power calibration.

[0179] As practical application demands increase, vector signal sources often require the addition of more digital filters in the digital baseband section to achieve functions such as digital predistortion, frequency response compensation, spurious suppression, and phase noise suppression. Simultaneously, multiple stages of RF devices may be connected after the RF output, such as RF amplifiers, variable attenuators, filters, isolators, or the RF device under test. The frequency response of these additional devices further affects the amplitude distribution of the broadband vector signal, making it difficult to guarantee the accuracy of the final output signal power even if only the original RF channel frequency response is considered.

[0180] Therefore, the frequency response of all newly added filters and RF devices needs to be incorporated into the calculation of the first baseband gain coefficient so that, regardless of how the structure of the vector signal source 2 is expanded, the calibration method proposed in this application can obtain accurate broadband vector signal power at the output of the last stage RF device.

[0181] Please refer to Figure 9 The vector signal source 2 extends by connecting at least one filter 2333 between the output of the gainer 2332 and the input of the digital-to-analog converter 241, and their frequency responses are denoted as follows: ... Then the first baseband gain coefficient can be expanded as follows:

[0182]

[0183] Therefore, the first baseband gain coefficient is determined based on the power spectral density of the bandwidth calibration signal, the power spectral density of the vector waveform data to be played, the frequency response of the RF processing module 24, and the frequency response of each filter 2333.

[0184] The vector signal source 2 also extends to include at least one radio frequency device 26 between the output of the automatic level control module 25 and the radio frequency output, the frequency responses of which are denoted as follows: ... Then the first baseband gain coefficient can be expanded as follows:

[0185]

[0186] Therefore, the first baseband gain coefficient is determined based on the power spectral density of the bandwidth calibration signal, the power spectral density of the vector waveform data to be played, the frequency response of the RF processing module 24, the frequency response of each filter 2333, and the frequency response of each RF device 26.

[0187] It should be noted that when the filter 2333 and the RF device 26 are added, the structure described above can be continued.

[0188] Another embodiment provides a calibration method based on the output power of a vector signal source 2. This method is applied to the vector signal source 2, which is the same as the vector signal source 2 in the above embodiment. The following only describes the hardware directly associated with this method.

[0189] In one embodiment, the vector signal source 2 includes a calibration signal generator 231, a vector signal generator 232, a signal control module 233, a radio frequency processing module 24, and an automatic level control module 25.

[0190] In one embodiment, a calibration signal generator 231 generates a preset bandwidth calibration signal for power calibration. The preset bandwidth calibration signal includes both single-tone signals and wideband signals. The wideband signal is designed to have a power spectral density that is the same as or very close to the vector waveform data to be played, ensuring that the frequency response of the bandwidth calibration signal in the radio frequency channel is highly consistent with that of the vector signal.

[0191] In one embodiment, the vector signal generator 232 is used to acquire vector waveform data to be played and generate a vector baseband signal based on the vector waveform data.

[0192] In one embodiment, the signal control module 233 includes a selector 2331 and a gainer 2332 connected in sequence. The input of the selector 2331 is selectively connected to the outputs of the calibration signal generator 231 and the vector signal generator 232. The output of the selector 2331 is connected to the input of the gainer 2332, and the output of the gainer 2332 serves as the output of the signal control module 233. The signal control module 233 is used to select between a bandwidth calibration signal and a vector baseband signal, and applies different baseband gain coefficients according to the selected signal. When the selector 2331 selects the bandwidth calibration signal, the signal control module 233 adjusts the bandwidth calibration signal using a first baseband gain coefficient and outputs a calibration signal for power calibration; when the selector 2331 selects the vector baseband signal, the signal control module 233 adjusts the vector baseband signal using a second baseband gain coefficient and outputs a target vector baseband signal.

[0193] In one embodiment, the radio frequency processing module 24 is connected to the signal control module 233 and is used to perform digital-to-analog conversion and radio frequency modulation on the calibration signal to generate a power calibration signal. It is also used to perform digital-to-analog conversion and radio frequency modulation on the target vector baseband signal to generate a target radio frequency vector signal.

[0194] In one embodiment, the input terminal of the automatic level control module 25 is connected to the output terminal of the radio frequency processing module 24, and the output terminal of the automatic level control module 25 is connected to the radio frequency output terminal of the vector signal source 2. The automatic level control module 25 is used to control the output power of the final vector signal.

[0195] Specifically, when selector 2331 selects the bandwidth calibration signal, automatic level control module 25 is in closed-loop mode. Automatic level control module 25 adjusts the gain of the RF channel in real time by detecting the power calibration signal output by modulator 242, ensuring that the output RF power is stabilized at the set target power. After closed-loop operation, automatic level control module 25 calculates and stores calibration parameters based on the output RF power in the stable state for power compensation of the vector signal.

[0196] When selector 2331 selects a vector baseband signal, automatic level control module 25 is in open-loop state. Automatic level control module 25 adjusts the gain of RF channel according to the acquired calibration parameters so that the power of the vector signal output by the final RF output terminal reaches the set target power.

[0197] Please refer to Figure 10 After introducing the vector signal source 2, the calibration method based on the output power of the vector signal source 2 provided in this application is the same as the method executed by the processor 21 of the vector signal source 2 in the above embodiment. Again, only the more important parts are described here. The following section will focus on... Figure 10 The flowchart in the document will be explained in detail.

[0198] Before calibrating vector signal source 2, the power spectral density of the vector waveform data to be played is first obtained, followed by the power spectral density of the bandwidth calibration signal. Simultaneously, the frequency response of the radio frequency processing module 24 also needs to be acquired. Specifically, the sampling point sequences of the bandwidth calibration signal and the vector waveform data to be played are obtained. Fourier transforms are then performed on both sequences to determine their corresponding frequency point sequences. The power spectral density of the bandwidth calibration signal is determined based on its frequency point sequence and the number of transform points in the Fourier transform. Similarly, the power spectral density of the vector waveform data to be played is determined based on its frequency point sequence and the number of transform points in the Fourier transform.

[0199] It should be noted that when the number of transformation points of the Fourier transform is less than the number of sampling points of the vector waveform data, the vector waveform data to be played is segmented so that the number of sampling points of each segment of the vector waveform data to be played is equal to the number of transformation points of the Fourier transform.

[0200] After completing the above three calculations, the first baseband gain coefficient is determined based on the power spectral density of the bandwidth calibration signal, the power spectral density of the vector waveform data to be played, and the frequency response of the radio frequency processing module 24. The specific determination process of the first baseband gain coefficient has been clearly explained in the above embodiment of the vector signal source 2, and will not be repeated here.

[0201] The first baseband gain coefficient corresponds to the gain coefficient of the bandwidth calibration signal. Therefore, after calculating the first baseband gain coefficient, it is assigned to the gain unit 2332 in the signal control module 233. The selector 2331 in the signal control module 233 selects the bandwidth calibration signal, and the gain unit 2332 adjusts the bandwidth calibration signal using the first baseband gain coefficient and outputs a calibration signal for power calibration. After this, the vector signal source 2 enters the closed-loop state of the automatic level control module 25. The automatic level control module 25 detects the RF output power in real time and automatically adjusts the gain of the RF channel to make its output power reach the target power set by the user interface. When the automatic level control module 25 reaches a stable state, it indicates that the automatic level control module 25 has successfully boosted or attenuated the bandwidth calibration signal to the target power.

[0202] After the automatic level control module 25 completes closed-loop operation and the output power stabilizes, it switches to open-loop mode to keep the RF channel gain fixed, preparing for vector signal playback. At this time, the digital gain coefficient adjusted by the signal control module 233 for the bandwidth calibration signal can be obtained. The second baseband gain coefficient is determined based on the digital gain coefficient and the first baseband gain coefficient. Specifically, the sampling point sequence of the bandwidth calibration signal is acquired, amplitude is detected on the sampling point sequence, and the sampling point sequence is normalized based on the amplitude detection result. The gain value required for the digital gain coefficient of the bandwidth calibration signal to reach the preset value is used as the digital gain coefficient. The specific process for determining the second baseband gain coefficient has been clearly explained in the above embodiment of the vector signal source and will not be repeated here.

[0203] It should be noted that those skilled in the art should understand that the calculation of the second baseband gain coefficient can also be performed immediately after the calculation of the first baseband gain coefficient.

[0204] After calibrating the automatic level control module 25, the selector 2331 in the signal control module 233 can select the vector baseband signal and obtain the second baseband gain coefficient. The second baseband gain coefficient corresponds to the gain coefficient of the vector baseband signal. Therefore, when the selector 2331 selects the vector baseband signal, the second baseband gain coefficient can be configured to the gain unit 2332 in the signal control module 233. The gain unit 2332 uses the second baseband gain coefficient to adjust the vector baseband signal and outputs the target vector baseband signal. After the target vector baseband signal passes through the RF channel and the open-loop fixed gain of the automatic level control module 25, the vector signal can obtain a stable RF power at the RF output terminal that meets the set target power.

[0205] This completes a calibration process based on the vector signal output from vector signal source 2. After this, if it's necessary to switch the RF frequency of RF processing module 24, there's no need to recalculate the power spectral density of the vector signal to be played, as this power spectral density depends only on the waveform to be played and is independent of the RF frequency. Therefore, when switching frequencies, the frequency response of RF processing module 24 corresponding to the current RF frequency can be directly read, and the frequency response of RF processing module 24 from the previous calibration process can be updated. The first baseband gain coefficient is then recalculated based on the updated frequency response, and a new round of calibration is performed according to the above calibration process. This avoids the computationally intensive power spectral density calculation step, significantly improving the frequency switching speed of the signal source and meeting the requirements of vector signal source 2 for rapid frequency switching.

[0206] It should be noted that the radio frequency (RF) frequency refers to the center frequency of the RF signal output by the RF processing module 24 of the vector signal source 2 after modulating and up-converting the baseband signal. This RF frequency is usually provided by the local oscillator 243 and set by the user. The frequency response of the RF channel is related to the RF frequency. Therefore, during calibration, it is necessary to read the corresponding frequency response based on the RF frequency of the signal playback to determine the corresponding first baseband gain coefficient.

[0207] Those skilled in the art will understand that all or part of the functions of the various methods in the above embodiments can be implemented by hardware or by computer programs. When all or part of the functions in the above embodiments are implemented by computer programs, the program can be stored in a computer-readable storage medium, which may include: read-only memory, random access memory, disk, optical disk, hard disk, etc., and the program is executed by a computer to achieve the above functions. For example, the program can be stored in the memory of a device, and when the program in the memory is executed by the processor, all or part of the above functions can be achieved. In addition, when all or part of the functions in the above embodiments are implemented by computer programs, the program can also be stored in a server, another computer, disk, optical disk, flash drive, or external hard drive, etc., and can be downloaded or copied to the memory of a local device, or the system of the local device can be updated. When the program in the memory is executed by the processor, all or part of the functions in the above embodiments can be achieved.

[0208] The above examples illustrate this application only to aid understanding and are not intended to limit its scope. Those skilled in the art to which this application pertains can make various simple deductions, modifications, or substitutions based on the ideas presented.

Claims

1. A vector signal source, characterized in that, It includes a digital signal processing module, a radio frequency processing module, an automatic level control module, and a processor; The digital signal processing module includes a calibration signal generator, a vector signal generator, and a signal control module; The calibration signal generator is used to generate a preset bandwidth calibration signal; The vector signal generator is used to acquire the vector waveform data to be played and to generate a vector baseband signal based on the vector waveform data to be played. The signal control module is used to select the bandwidth calibration signal and the vector baseband signal; when the bandwidth calibration signal is selected, the signal control module adjusts the bandwidth calibration signal using a first baseband gain coefficient and outputs a calibration signal for power calibration; when the vector baseband signal is selected, the signal control module adjusts the vector baseband signal using a second baseband gain coefficient and outputs a target vector baseband signal. The radio frequency processing module is connected to the signal control module and is used to perform digital-to-analog conversion and radio frequency modulation on the calibration signal to generate a power calibration signal. And for performing digital-to-analog conversion and radio frequency modulation on the target vector baseband signal to generate a target radio frequency vector signal; The automatic level control module is connected to the radio frequency processing module. When the bandwidth calibration signal is selected, the automatic level control module is in a closed-loop state, and in the closed-loop state, it performs power calibration according to the power calibration signal to obtain calibration parameters. When the vector baseband signal is selected, the automatic level control module is in an open-loop state, and in the open-loop state, it adjusts the gain of the automatic level control module according to the calibration parameters to output a vector signal. The processor is used for: The first baseband gain coefficient is obtained, and the first baseband gain coefficient is determined based on the power spectral density of the bandwidth calibration signal, the power spectral density of the vector waveform data to be played, and the frequency response of the radio frequency processing module. Obtain the digital gain coefficient of the bandwidth calibration signal adjusted by the signal control module; The second baseband gain coefficient is determined based on the digital gain coefficient and the first baseband gain coefficient; When the bandwidth calibration signal is selected, the first baseband gain coefficient is configured to the signal control module; When the vector baseband signal is selected, the second baseband gain coefficient is configured to the signal control module.

2. The vector signal source as described in claim 1, characterized in that, The power spectral density of the bandwidth calibration signal and the power spectral density of the vector waveform data to be played are obtained in the following way: Obtain the sampling point sequence of the bandwidth calibration signal and the sampling point sequence of the vector waveform data to be played; Fourier transforms are performed on the sampling point sequence of the bandwidth calibration signal and the sampling point sequence of the vector waveform data to be played, respectively, to determine the frequency point sequence of the bandwidth calibration signal and the frequency point sequence of the vector waveform data to be played. The power spectral density of the bandwidth calibration signal is determined based on the frequency point sequence of the bandwidth calibration signal and the number of transformation points of the Fourier transform. The power spectral density of the vector waveform data to be played is determined based on the frequency point sequence of the vector waveform data to be played and the number of transformation points of the Fourier transform.

3. The vector signal source as described in claim 2, characterized in that, When the number of transformation points of the Fourier transform is less than the number of sampling points of the vector waveform data to be played, the vector waveform data to be played is segmented so that the number of sampling points of each segment of the vector waveform data to be played is equal to the number of transformation points of the Fourier transform.

4. The vector signal source as described in claim 3, characterized in that, The bandwidth calibration signal includes single-tone signals and wideband signals; When the bandwidth calibration signal is a single-tone signal, the frequency response of the radio frequency processing module includes the frequency response of the single-tone signal in the radio frequency processing module and the frequency response of the vector waveform data to be played in the radio frequency processing module. When the bandwidth calibration signal is a wideband signal, the frequency response of the radio frequency processing module includes the frequency response of the wideband signal in the radio frequency processing module and the frequency response of the vector waveform data to be played in the radio frequency processing module. The frequency response of the single-tone signal in the radio frequency processing module is the frequency response value of the radio frequency processing module at a single frequency point in the single-tone signal. The frequency response of the broadband signal in the radio frequency processing module is the set of frequency response values ​​of the radio frequency processing module at multiple frequency points in the broadband signal. The frequency response of the vector waveform data to be played in the radio frequency processing module is a sequence of the frequency response values ​​of the radio frequency processing module within the bandwidth occupied by the vector waveform data to be played.

5. The vector signal source as described in claim 4, characterized in that, The frequency response of the radio frequency processing module is obtained in the following way: The vector signal source generates a calibration signal of a preset frequency and outputs it to the test equipment connected to the vector signal source. Acquire the sampling signal obtained by the test equipment sampling the calibration signal; The frequency response of the radio frequency processing module is determined based on the sampled signal and the calibration signal.

6. The vector signal source as described in claim 5, characterized in that, When the number of sampling points of the sampled signal output by the test device is greater than the number of transformation points of the Fourier transform, the number of transformation points of the Fourier transform is interpolated so that the number of sampling points of the sampled signal is equal to the number of transformation points of the Fourier transform; when the number of sampling points of the sampled signal output by the test device is less than the number of transformation points of the Fourier transform, the number of transformation points of the Fourier transform is decimated so that the number of sampling points of the sampled signal is equal to the number of transformation points of the Fourier transform.

7. The vector signal source as described in claim 1, characterized in that, The step of obtaining the digital gain coefficient for adjusting the bandwidth calibration signal by the signal control module includes: Obtain the sampling point sequence of the bandwidth calibration signal; Amplitude detection is performed on the sampling point sequence of the bandwidth calibration signal; The sampling point sequence of the bandwidth calibration signal is normalized according to the amplitude detection result, and the gain value required for the digital gain coefficient of the bandwidth calibration signal to reach the preset set value is taken as the digital gain coefficient.

8. The vector signal source as described in claim 1, characterized in that, Determining the second baseband gain coefficient based on the digital gain coefficient and the first baseband gain coefficient includes: The digital gain coefficient divided by the first baseband gain coefficient is the second baseband gain coefficient.

9. The vector signal source as described in claim 1, characterized in that, The vector signal source also includes a local oscillator, the signal control module includes a selector and a gainer connected in sequence, and the radio frequency processing module includes a digital-to-analog converter and a modulator connected in sequence. The input of the selector can be selectively connected to the output of the calibration signal generator and the vector signal generator. The output of the selector is connected to the input of the gain unit. The output of the gain unit is connected to the input of the digital-to-analog converter. The input of the modulator is connected to the output of the digital-to-analog converter and the output of the local oscillator. The output of the modulator is connected to the input of the automatic level control module. The digital-to-analog converter is used to convert the digital quantity of the calibration signal into the analog quantity of the calibration signal, and to convert the digital quantity of the target vector baseband signal into the analog quantity of the target vector baseband signal. The modulator receives the analog quantity of the calibration signal or the analog quantity of the target vector baseband signal from the digital-to-analog converter, and mixes it with the local oscillator signal output from the local oscillator to obtain a power calibration signal modulated to the radio frequency band and a target radio frequency vector signal, which are then output from the radio frequency output of the vector signal source through the automatic control module.

10. The vector signal source as described in claim 9, characterized in that, The vector signal source further includes at least one filter connected between the output of the gainer and the input of the digital-to-analog converter. The first baseband gain coefficient is determined based on the power spectral density of the bandwidth calibration signal, the power spectral density of the vector waveform data to be played, the frequency response of the RF processing module, and the frequency response of each filter. Alternatively, the vector signal source further includes at least one RF device connected between the output of the automatic level control module and the RF output. The first baseband gain coefficient is determined based on the power spectral density of the bandwidth calibration signal, the power spectral density of the vector waveform data to be played, the frequency response of the RF processing module, the frequency response of each filter, and the frequency response of each RF device.

11. A method for calibrating the output power of a vector signal source, characterized in that, The vector signal source includes a calibration signal generator, a vector signal generator, a signal control module, an RF processing module, and an automatic level control module. The calibration signal generator is used to generate a preset bandwidth calibration signal. The vector signal generator is used to acquire vector waveform data to be played and generate a vector baseband signal based on the vector waveform data to be played. The RF processing module is used to acquire a calibration signal corresponding to the bandwidth calibration signal and perform digital-to-analog conversion and RF modulation on the calibration signal to generate a power calibration signal. It is also used to acquire a target vector baseband signal corresponding to the vector baseband signal and perform digital-to-analog conversion and RF modulation on the target vector baseband signal to generate a target RF vector signal. The automatic level control module is used to perform power calibration based on the power calibration signal to obtain calibration parameters, and to adjust the gain of the automatic level control module based on the calibration parameters to output a vector signal; The calibration method for the output power of the vector signal source includes: Obtain the power spectral density of the vector waveform data to be played; Obtain the power spectral density of the bandwidth-calibrated signal; Obtain the frequency response of the radio frequency processing module; The first baseband gain coefficient is determined based on the power spectral density of the bandwidth calibration signal, the power spectral density of the vector waveform data to be played, and the frequency response of the radio frequency processing module. When the bandwidth calibration signal is selected, the first baseband gain coefficient is configured to the signal control module. The signal control module adjusts the bandwidth calibration signal using the first baseband gain coefficient and outputs the calibration signal for power calibration. Obtain the digital gain coefficient of the bandwidth calibration signal adjusted by the signal control module; The second baseband gain coefficient is determined based on the digital gain coefficient and the first baseband gain coefficient. When the vector baseband signal is selected, the second baseband gain coefficient is configured to the signal control module. The signal control module adjusts the vector baseband signal using the second baseband gain coefficient and outputs the target vector baseband signal.

12. The calibration method for the output power of a vector signal source as described in claim 11, characterized in that, The power spectral density of the bandwidth calibration signal and the power spectral density of the vector waveform data to be played are obtained in the following way: Obtain the sampling point sequence of the bandwidth calibration signal and the sampling point sequence of the vector waveform data to be played; Fourier transforms are performed on the sampling point sequence of the bandwidth calibration signal and the sampling point sequence of the vector waveform data to be played, respectively, to determine the frequency point sequence of the bandwidth calibration signal and the frequency point sequence of the vector waveform data to be played. The power spectral density of the bandwidth calibration signal is determined based on the frequency point sequence of the bandwidth calibration signal and the number of transformation points of the Fourier transform. The power spectral density of the vector waveform data to be played is determined based on the frequency point sequence of the vector waveform data to be played and the number of transformation points of the Fourier transform.

13. The calibration method for the output power of a vector signal source as described in claim 12, characterized in that, When the number of transformation points of the Fourier transform is less than the number of sampling points of the vector waveform data to be played, the vector waveform data to be played is segmented so that the number of sampling points of each segment of the vector waveform data to be played is equal to the number of transformation points of the Fourier transform.

14. The calibration method for the output power of a vector signal source as described in claim 11, characterized in that, Determining the second baseband gain coefficient based on the digital gain coefficient and the first baseband gain coefficient includes: The digital gain coefficient divided by the first baseband gain coefficient is the second baseband gain coefficient.

15. The calibration method for the output power of a vector signal source as described in claim 11, characterized in that, The step of obtaining the digital gain coefficient for adjusting the bandwidth calibration signal by the signal control module includes: Obtain the sampling point sequence of the bandwidth calibration signal; Amplitude detection is performed on the sampling point sequence of the bandwidth calibration signal; The sampling point sequence of the bandwidth calibration signal is normalized according to the amplitude detection result, and the gain value required for the digital gain coefficient of the bandwidth calibration signal to reach the preset set value is taken as the digital gain coefficient.

16. The calibration method for the output power of a vector signal source as described in claim 11, characterized in that, The calibration method for the output power of the vector signal source also includes: Determine whether the radio frequency of the radio frequency processing module has been switched. If so, read the frequency response corresponding to the radio frequency of the radio frequency processing module to update the frequency response of the radio frequency processing module, and calculate the first baseband gain coefficient based on the updated frequency response of the radio frequency processing module.

17. A computer-readable storage medium, characterized in that, The medium stores a computer program that can be executed by a processor to implement the method as described in any one of claims 11-16.

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