Wideband pulse measurement method and system based on vector network analyzer

Abstract

The present invention relates to the field of radio frequency measurement technology, and discloses a broadband pulse measurement method based on a vector network analyzer. Aiming at the problem that the device under test cannot withstand long-term high-power signals, a special measurement scheme is designed for the vector network analyzer. The radio frequency source signal is modulated by a pulse switch, and the signal is down-converted to an intermediate frequency after passing through the device under test, and the intermediate frequency is then pulse modulated and filtered. A pulse modulation source is designed for radio frequency and intermediate frequency signal modulation and reception sampling synchronization to ensure that the sampling bandwidth is within the positive pulse width of the pulse period. When sampling, a reference pulse rising edge is introduced to trigger the digital down-conversion working state. After software delay, sampling is performed to achieve synchronization between sampling and intermediate frequency signal, and the results are accurate, stable and fast. In addition, in order to achieve distortion of the intermediate frequency signal link after radio frequency modulation, a modulation signal is introduced to further modulate and improve it. This scheme can effectively measure the amplitude-frequency characteristics, phase and other characteristics of the device under test.

Description

Technical Field

[0001] The present invention relates to the technical field of radio frequency measurement, and in particular to a broadband pulse measurement method based on a vector network analyzer. Background Art

[0002] A vector network analyzer (VNA) is an important RF measurement instrument that measures the amplitude and phase of a network under test, thereby comprehensively characterizing its characteristics. Its advantages include high frequency resolution, wide frequency range, and high accuracy, enabling in-depth analysis of complex RF and microwave signals.

[0003] In the field of RF measurement, vector network analyzers (VNAs) are crucial for accurately measuring DUT characteristics (such as amplitude-frequency and phase). However, some DUTs cannot withstand the passage of high-power signals for extended periods, posing a measurement challenge. Existing technologies for addressing these challenges suffer from low measurement accuracy, poor stability, and slow sampling speeds. Summary of the Invention

[0004] The present invention aims to provide a broadband pulse measurement method and system based on a vector network analyzer to effectively solve the above problems.

[0005] A broadband pulse measurement method based on a vector network analyzer is applied to the measurement of a device under test by the vector network analyzer, and includes the following steps:

[0006] S1. Generate a pulsed RF signal: The RF source generates a RF source signal according to pre-configured data, and the pulse modulation source generates a first control signal to control the first pulse switch to modulate the RF source signal to obtain a pulsed first pulse RF signal;

[0007] S2. DUT response: The first pulsed RF signal reaches the DUT through the transmission link, and the DUT responds to it to obtain a second pulsed RF signal;

[0008] S3 mixing: receiving a second pulsed RF signal and mixing the second pulsed RF signal with a local oscillator signal generated by an oscillator to obtain a first intermediate frequency signal;

[0009] S4 obtains a pulse-shaped intermediate frequency signal: the pulse modulation source generates a second control signal to control the second pulse switch to modulate the first intermediate frequency signal, and then filters the modulated first intermediate frequency signal to obtain a pulse intermediate frequency signal to be sampled;

[0010] S5. Sampling: Introduce the reference pulse of the pulse modulation source and wait for the measurement trigger; after the measurement trigger, perform excitation configuration and generate a pulse; when the digital down-conversion is stable after the pulse rising edge, the digital broadband filter group samples the pulse intermediate frequency signal to be sampled.

[0011] Furthermore, the reference pulse introduced into the pulse modulation source has a fixed period and precise time interval. The reference pulse is a periodic pulse and serves as a stable time reference, so that the RF source and the first pulse switch and the mixing device and the second pulse switch of the vector network analyzer can operate on the same time scale.

[0012] Furthermore, the pulse modulation source is used for RF signal modulation, IF signal modulation and receiving sampling synchronization respectively, so that the sampling bandwidth always falls within the positive pulse width of the pulse period.

[0013] Furthermore, the digital broadband filter bank includes a CIC digital filter and an FIR filter:

[0014] A CIC digital filter decimates and samples the intermediate frequency signal;

[0015] The FIR filter performs FIR filtering on the decimated samples.

[0016] Furthermore, the frequency of the first intermediate frequency signal obtained through mixing is 5.8 MHz, or is adjusted to a suitable frequency according to the characteristics of the device under test.

[0017] A system for a broadband pulse measurement method based on a vector network analyzer, which implements the above-mentioned broadband pulse measurement method based on a vector network analyzer, comprises:

[0018] Device for generating a pulsed radio frequency signal: a radio frequency source generates a radio frequency source signal according to preconfigured data, a pulse modulation source generates a first control signal to control a first pulse switch to modulate the radio frequency source signal, and obtains a pulsed first pulse radio frequency signal;

[0019] Device under test: The first pulsed RF signal reaches the device under test through the transmission link, and the device under test responds to it and obtains a second pulsed RF signal;

[0020] A frequency mixing device receives the second pulsed radio frequency signal and mixes the second pulsed radio frequency signal with a local oscillator signal generated by an oscillator to obtain a first intermediate frequency signal;

[0021] A device for generating a pulsed intermediate frequency signal: a pulse modulation source generates a second control signal to control a second pulse switch to modulate the first intermediate frequency signal, and then filters the modulated first intermediate frequency signal to obtain a pulse intermediate frequency signal to be sampled;

[0022] Sampling device: Digital broadband filter group, used to sample the pulse intermediate frequency signal after the rising edge of the pulse and when the digital down-conversion is stable.

[0023] A system for a broadband pulse measurement method based on a vector network analyzer includes a vector network analyzer and a device under test. The vector network analyzer includes a radio frequency source signal, a pulse modulation source, a first pulse switch to form a device for generating a pulsed radio frequency signal, a frequency mixing device, a second pulse switch, and a digital broadband filter bank.

[0024] The RF source generates a RF source signal according to pre-configured data, and the pulse modulation source generates a first control signal to control a first pulse switch to modulate the RF source signal to obtain a pulse-shaped first pulse RF signal;

[0025] The first pulsed RF signal reaches the device under test through the transmission link, and the device under test responds to it to obtain a second pulsed RF signal;

[0026] receiving a second pulsed radio frequency signal and mixing the second pulsed radio frequency signal with a local oscillator signal generated by an oscillator to obtain a first intermediate frequency signal;

[0027] The pulse modulation source generates a second control signal to control the second pulse switch to modulate the first intermediate frequency signal, and then filters the modulated first intermediate frequency signal to obtain a pulse intermediate frequency signal to be sampled;

[0028] The digital broadband filter group is used to sample the pulse intermediate frequency signal after the rising edge of the pulse and when the digital down-conversion is stable.

[0029] The present invention has the beneficial effects:

[0030] 1. The present invention uses a pulse modulation source for RF signal and IF signal modulation and reception sampling synchronization, ensuring that the sampling bandwidth falls precisely within the positive pulse width of the pulse period, thereby achieving continuous and stable data sampling.

[0031] 2. A unique control method, by introducing a reference pulse from a pulse modulation source to trigger sampling and combining it with software delay settings, achieves high-precision synchronization between the sampling bandwidth and the intermediate frequency signal after pulse modulation, ensuring the accuracy and stability of the sampling results and significantly improving the sampling speed.

[0032] 3. To address the distortion problem caused by the intermediate frequency signal transmission link, an innovative re-modulation method is introduced to effectively improve distortion such as pulse edges and enhance measurement accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 is a schematic diagram of a vector network analyzer;

[0034] Figure 2 Flowchart of this method;

[0035] Figure 3 This is an example diagram of the sampling results;

[0036] Figure 4 This is a diagram of the specific sampling process. DETAILED DESCRIPTION

[0037] The present invention will be further described in detail below with reference to the embodiments and the accompanying drawings, but the embodiments of the present invention are not limited thereto.

[0038] Example 1

[0039] See also Figures 1 to 4 :

[0040] A broadband pulse measurement method based on a vector network analyzer is applied to the measurement of a device under test by the vector network analyzer, and includes the following steps:

[0041] S1. Generate a pulsed RF signal: The RF source generates a RF source signal according to pre-configured data, and the pulse modulation source generates a first control signal to control the first pulse switch to modulate the RF source signal to obtain a pulsed first pulse RF signal;

[0042] S2. DUT response: The first pulsed RF signal reaches the DUT through the transmission link, and the DUT responds to it to obtain a second pulsed RF signal;

[0043] S3 mixing: receiving a second pulsed RF signal and mixing the second pulsed RF signal with a local oscillator signal generated by an oscillator to obtain a first intermediate frequency signal;

[0044] S4 obtains a pulse-shaped intermediate frequency signal: the pulse modulation source generates a second control signal to control the second pulse switch to modulate the first intermediate frequency signal, and then filters the modulated first intermediate frequency signal to obtain a pulse intermediate frequency signal to be sampled;

[0045] S5. Sampling: Introduce the reference pulse of the pulse modulation source and wait for the measurement trigger; after the measurement trigger, perform excitation configuration and generate a pulse; when the digital down-conversion is stable after the pulse rising edge, the digital broadband filter group samples the pulse intermediate frequency signal to be sampled.

[0046] The RF source of the present invention generates an RF source signal based on preconfigured data. This signal is modulated by pulse switch 1 under the control of control signal P1 generated by the pulse modulation source, thereby obtaining a pulsed first pulse RF signal. After this first pulse RF signal reaches the device under test via the transmission link, the device under test responds to it and generates a second pulse RF signal. The second pulse RF signal is then received and mixed with the local oscillator signal generated by the oscillator to obtain a first intermediate frequency signal. Simultaneously, the pulse modulation source generates a control signal P0 to control pulse switch 0 to modulate the first intermediate frequency signal again. The modulated first intermediate frequency signal is then filtered to obtain a pulse intermediate frequency signal to be sampled. Finally, a digital broadband filter group samples this pulse intermediate frequency signal to be sampled.

[0047] In terms of applicability to DUTs, traditional vector network analyzers may not be suitable for DUTs that cannot withstand long-term high-power signals. However, this solution uses pulse signals to measure the characteristics of such special DUTs.

[0048] In terms of signal modulation and processing, traditional methods usually use continuous signal modulation and processing, while the present invention adds pulse radio frequency modulation and intermediate frequency pulse modulation, which can better control the signal and improve distortion;

[0049] Regarding sampling synchronization and accuracy, the traditional method may have shortcomings. The present invention achieves precise synchronization of the sampling bandwidth and the intermediate frequency signal by introducing a reference pulse and software-controlled delay, thereby improving the accuracy and stability of the sampling results and accelerating the sampling speed.

[0050] In terms of intermediate frequency signal processing, traditional methods may be relatively simple and difficult to effectively improve the distortion caused by long links. The present invention optimizes this problem by introducing a pulse modulation signal for further modulation.

[0051] Furthermore, the reference pulse introduced into the pulse modulation source has a fixed period and precise time interval. The reference pulse is a periodic pulse and serves as a stable time reference, so that the RF source and the first pulse switch 1 of the vector network analyzer and the mixing device and the second pulse switch 0 can operate on the same time scale.

[0052] Furthermore, the pulse modulation source is used for RF signal modulation, IF signal modulation and receiving sampling synchronization respectively, so that the sampling bandwidth always falls within the positive pulse width of the pulse period.

[0053] Furthermore, the digital broadband filter bank includes a CIC digital filter and an FIR filter:

[0054] A CIC digital filter decimates and samples the intermediate frequency signal;

[0055] The FIR filter performs FIR filtering on the decimated samples.

[0056] Furthermore, the frequency of the first intermediate frequency signal obtained through mixing is 5.8 MHz or is adjusted to a suitable frequency according to the characteristics of the device under test.

[0057] A system for a broadband pulse measurement method based on a vector network analyzer, which implements the above-mentioned broadband pulse measurement method based on a vector network analyzer, comprises:

[0058] Device for generating a pulsed radio frequency signal: a radio frequency source generates a radio frequency source signal according to preconfigured data, a pulse modulation source generates a first control signal to control a first pulse switch to modulate the radio frequency source signal, and obtains a pulsed first pulse radio frequency signal;

[0059] Device under test: The first pulsed RF signal reaches the device under test through the transmission link, and the device under test responds to it and obtains a second pulsed RF signal;

[0060] A frequency mixing device receives the second pulsed radio frequency signal and mixes the second pulsed radio frequency signal with a local oscillator signal generated by an oscillator to obtain a first intermediate frequency signal;

[0061] A device for generating a pulsed intermediate frequency signal: a pulse modulation source generates a second control signal to control a second pulse switch to modulate the first intermediate frequency signal, and then filters the modulated first intermediate frequency signal to obtain a pulse intermediate frequency signal to be sampled;

[0062] Sampling device: Digital broadband filter group, used to sample the pulse intermediate frequency signal after the rising edge of the pulse and when the digital down-conversion is stable.

[0063] A system for a broadband pulse measurement method based on a vector network analyzer includes a vector network analyzer and a device under test. The vector network analyzer includes a radio frequency source signal, a pulse modulation source, a first pulse switch to form a device for generating a pulsed radio frequency signal, a frequency mixing device, a second pulse switch, and a digital broadband filter bank.

[0064] The RF source generates a RF source signal according to pre-configured data, and the pulse modulation source generates a first control signal to control a first pulse switch to modulate the RF source signal to obtain a pulse-shaped first pulse RF signal;

[0065] The first pulsed RF signal reaches the device under test through the transmission link, and the device under test responds to it to obtain a second pulsed RF signal;

[0066] receiving a second pulsed radio frequency signal and mixing the second pulsed radio frequency signal with a local oscillator signal generated by an oscillator to obtain a first intermediate frequency signal;

[0067] The pulse modulation source generates a second control signal to control the second pulse switch to modulate the first intermediate frequency signal, and then filters the modulated first intermediate frequency signal to obtain a pulse intermediate frequency signal to be sampled;

[0068] The digital broadband filter group is used to sample the pulse intermediate frequency signal after the rising edge of the pulse and when the digital down-conversion is stable.

[0069] Example 2

[0070] The computer side sends data to the mainboard DIG801. When the data is sent, it means that the excitation is ready. Then the data sent by the computer side is pre-configured. During the pre-configuration process, the excitation is read and the pre-configured excitation data is automatically configured as the excitation point. After the pre-configuration is completed, the reference pulse of the pulse modulation source is introduced, and the measurement trigger is waited for. After the measurement is triggered, the excitation configuration is performed. After the excitation configuration is completed, the excitation point data is read again and a pulse is generated: the pulse modulation source generates a control signal P1, and the RF source signal is switched modulated by the control signal P1 to obtain a first pulse RF signal and a second pulse RF signal is obtained by passing it through the device to be tested, and then the first intermediate frequency signal is obtained by mixing. After that, the pulse modulation source generates a control signal P0, and the first intermediate frequency signal is switched modulated by the control signal P0, and then filtered to obtain the pulse intermediate frequency signal to be sampled. Then, after the rising edge of the pulse, the digital down-conversion is stable, which is the DDC stability.

[0071] When the digital down-conversion is stable, the digital broadband filter group starts data acquisition. When the falling edge of the reference pulse arrives, the data acquisition is stopped and then data processing is performed. Figure 2 The data obtained in the above example is sinusoidal, and each cycle of the sine corresponds to the period from the start of sampling to the arrival of the falling edge at the same time.

[0072] After completion, the stimulus point is switched and the measurement trigger is returned.

[0073] It will be understood that the above embodiments are merely exemplary embodiments for illustrating the principles of the present invention, and the present invention is not limited thereto. Persons skilled in the art will be able to make various modifications and improvements without departing from the spirit and substance of the present invention, and such modifications and improvements are also considered to be within the scope of protection of the present invention.

Claims

1. A broadband pulse measurement method based on a vector network analyzer, applied to the measurement of a device under test by a vector network analyzer, characterized in that: The following steps are involved: S1. Generate a pulsed RF signal: the RF source generates a RF source signal according to pre-configured data, and the pulse modulation source generates a first control signal (P1) to control the first pulse switch (1) to modulate the RF source signal to obtain a pulsed first pulse RF signal; S2. DUT response: The first pulsed RF signal reaches the DUT through the transmission link, and the DUT responds to it to obtain a second pulsed RF signal; S3 mixing: receiving the second pulsed RF signal and mixing it with the local oscillator signal generated by the oscillator to obtain a first intermediate frequency signal; S4. Generate a pulsed intermediate frequency signal: the pulse modulation source generates a second control signal (P0) to control the second pulse switch (0) to modulate the first intermediate frequency signal, and then filter the modulated first intermediate frequency signal to obtain a pulse intermediate frequency signal to be sampled; S5. Sampling: Introducing the reference pulse from the pulse modulation source and waiting for the measurement trigger. After the measurement is triggered, excitation configuration is performed and a pulse is generated; when the digital down-conversion is stable after the rising edge of the pulse, the digital broadband filter group samples the pulse intermediate frequency signal to be sampled.

2. The broadband pulse measurement method based on a vector network analyzer according to claim 1, characterized in that: The reference pulse introduced into the pulse modulation source has a fixed period and a precise time interval. The reference pulse is a periodic pulse and serves as a stable time reference, so that the radio frequency source and the first pulse switch (1) of the vector network analyzer and the mixing device and the second pulse switch (0) can operate on the same time scale.

3. The broadband pulse measurement method based on a vector network analyzer according to claim 1, characterized in that: The pulse modulation source is used for RF signal modulation, IF signal modulation and receiving sampling synchronization respectively, so that the sampling bandwidth always falls within the positive pulse width of the pulse period.

4. The broadband pulse measurement method based on a vector network analyzer according to claim 1, characterized in that: The digital broadband filter group includes a CIC digital filter and an FIR filter: A CIC digital filter decimates and samples the intermediate frequency signal; The FIR filter performs an FIR filtering operation on the decimated samples.

5. The broadband pulse measurement method based on a vector network analyzer according to claim 1, characterized in that: The frequency of the first intermediate frequency signal obtained by mixing is 5.8 MHz or is adjusted to a suitable frequency according to the characteristics of the device under test.

6. A system for a broadband pulse measurement method based on a vector network analyzer, applied to implement the method according to any one of claims 1 to 5, characterized in that: include: A device for generating a pulsed radio frequency signal: a radio frequency source generates a radio frequency source signal according to preconfigured data, a pulse modulation source generates a first control signal (P1) to control a first pulse switch (1) to modulate the radio frequency source signal, and obtain a pulsed first pulse radio frequency signal; Device under test: The first pulsed RF signal reaches the device under test through the transmission link, and the device under test responds to it to obtain a second pulsed RF signal; A frequency mixing device receives the second pulsed radio frequency signal and mixes the second pulsed radio frequency signal with a local oscillator signal generated by an oscillator to obtain a first intermediate frequency signal; A device for generating a pulse-shaped intermediate frequency signal: a pulse modulation source generates a second control signal (P0) to control a first pulse switch (1) to modulate the first intermediate frequency signal, and then filters the modulated first intermediate frequency signal to obtain a pulse intermediate frequency signal to be sampled; Sampling device: Digital broadband filter group, used to sample the pulse intermediate frequency signal after the rising edge of the pulse and when the digital down-conversion is stable.

7. A system for a broadband pulse measurement method based on a vector network analyzer, comprising a vector network analyzer and a device under test, characterized in that: The vector network analyzer includes a device for generating a pulsed radio frequency signal composed of a radio frequency source signal, a pulse modulation source, and a first pulse switch (1), a frequency mixing device, the first pulse switch (1), and a digital broadband filter group; The radio frequency source generates a radio frequency source signal according to pre-configured data, and the pulse modulation source generates a first control signal (P1) to control a first pulse switch (1) to modulate the radio frequency source signal to obtain a pulse-shaped first pulse radio frequency signal; The first pulsed RF signal reaches the device under test through the transmission link, and the device under test responds to it to obtain a second pulsed RF signal; receiving a second pulsed radio frequency signal and mixing the second pulsed radio frequency signal with a local oscillator signal generated by an oscillator to obtain a first intermediate frequency signal; The pulse modulation source generates a second control signal (P0) to control the first pulse switch (1) to modulate the first intermediate frequency signal, and then filters the modulated first intermediate frequency signal to obtain a pulse intermediate frequency signal to be sampled; The digital broadband filter group is used to sample the pulse intermediate frequency signal after the rising edge of the pulse and when the digital down-conversion is stable.

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