Phase noise measurement method and system based on vector network analyzer hardware

Abstract

The invention discloses a phase noise measurement method and system based on vector network analyzer hardware, and relates to the technical field of communication measurement instruments and meters, and the method comprises the steps: receiving dual-channel ADC data, preprocessing the dual-channel ADC data to obtain preprocessed baseband complex IQ data, carrying out the phase analysis of the preprocessed baseband complex IQ data to obtain phase data, and calculating the phase noise of the baseband complex IQ data according to the phase data. Performing cross-correlation operation and amplitude analysis on the phase data to obtain phase noise data; carrying out amplitude analysis on the preprocessed baseband complex IQ data to obtain amplitude data, carrying out dual-channel complex cumulative average operation on the amplitude data to obtain amplitude modulation noise data, and processing to obtain a phase noise spectrum result and an amplitude modulation noise spectrum result; and performing peak detection and stray judgment on the phase noise spectrum result and the amplitude modulation noise spectrum result to obtain a stray identification result, and performing stray elimination on the stray identification result to obtain a final phase noise measurement value and an amplitude modulation noise measurement value.

Description

Technical Field

[0001] This invention relates to the field of communication measurement instruments and meters technology, specifically a phase noise measurement method and system based on vector network analyzer hardware. Background Technology

[0002] With the rapid development of science and technology, signal sources, as the fundamental signal sources for electronic systems such as receivers, radio communications, Doppler radar, and navigation, have gradually become an important indicator of the development of modern radio communication technology and time and frequency measurement and control technology. The development of signal sources with high frequency stability and reliability is of great significance to a country's scientific and technological progress, national economic growth, and national defense modernization. Phase noise, as a measure of this indicator of a signal source, has become a key factor restricting further improvements in the performance of electronic measurement systems.

[0003] For large-scale industrial production, multiple devices need to operate simultaneously, which is extremely costly. Therefore, it is necessary to study phase noise measurement systems that are more suitable for industrial production. Since some industrial production tests do not have high requirements for measurement accuracy, when conducting large-scale tests, the requirements for cost and testing efficiency are high. Therefore, it is particularly important to study low-cost and high-efficiency phase noise measurement systems. Summary of the Invention

[0004] To address the shortcomings mentioned in the background section, the present invention aims to provide a phase noise measurement method and system based on vector network analyzer hardware.

[0005] Firstly, the objective of this invention can be achieved through the following technical solution: a phase noise measurement method based on vector network analyzer hardware, the method comprising the following steps: Receive dual-channel ADC data, preprocess the dual-channel ADC data to obtain preprocessed baseband complex IQ data, perform phase analysis on the preprocessed baseband complex IQ data to obtain phase data, and perform cross-correlation and amplitude analysis on the phase data to obtain phase noise data. Amplitude analysis is performed on the preprocessed baseband complex IQ data to obtain amplitude data. Dual-channel complex cumulative averaging is performed on the amplitude data to obtain amplitude modulation noise data. The phase noise data and amplitude modulation noise data are processed to obtain phase noise spectrum results and amplitude modulation noise spectrum results. Peak detection and spurious detection are performed on the phase noise spectrum results and amplitude modulation noise spectrum results to obtain spurious identification results. Spurious removal is then performed on the spurious identification results to obtain the final phase noise measurement value and amplitude modulation noise measurement value.

[0006] In conjunction with the first aspect, in some implementations of the first aspect, the method further includes: the dual-channel ADC data is obtained by post-processing the test signal using a vector network analyzer.

[0007] In conjunction with the first aspect, in some implementations of the first aspect, the method further includes: the testing process of the vector network analyzer: Set the output RF output switch of the vector network analyzer to the off state, split the signal under test into two signals through the power divider, and input the two signals through the PORT1 and PORT2 test ports of the vector network analyzer, thereby realizing the hardware channel construction of the dual-channel cross-correlation digital phase noise measurement circuit. By acquiring the ADC data inside the vector network analyzer, the intermediate frequency signal after downconversion of the two signals can be obtained as the dual-channel ADC data.

[0008] In conjunction with the first aspect, in some implementations of the first aspect, the method further includes: the process of preprocessing the dual-channel ADC data involves digitally down-converting the acquired dual-channel ADC data, decimating and filtering the data according to the analyzed frequency offset range, and generating preprocessed baseband complex IQ data. In conjunction with the first aspect, in some implementations of the first aspect, the method further includes: the process of performing cross-correlation calculations and amplitude analysis on the phase data to obtain phase noise data: Frequency difference analysis is performed on the phase data to generate frequency difference compensation data for the digital frequency synthesizer module, which is used to offset the measurement error caused by frequency difference during phase noise measurement. Cross-correlation operation is performed on the phase data acquired by the dual-channel ADC. The FFT operator can accelerate the speed and efficiency of cross-correlation operation and generate phase noise data.

[0009] In conjunction with the first aspect, in some implementations of the first aspect, the method further includes: the process of processing the phase noise data and amplitude modulation noise data to obtain the phase noise spectrum result and the amplitude modulation noise spectrum result, comprising: The phase noise data and amplitude modulation noise data are segmented, overlapped, and windowed by the spectrum estimation module, and then the power spectrum is estimated to finally obtain the phase noise spectrum result and amplitude modulation noise spectrum result.

[0010] In conjunction with the first aspect, in some implementations of the first aspect, the method further includes: the process of acquiring the final phase noise measurement value and amplitude modulation noise measurement value, comprising: The phase noise spectrum and amplitude modulation noise spectrum output by the spectrum estimation module are generated by root mean square detection. According to the settings, they are then smoothed. The display point frequency is fixed, and the logarithmic frequency is stepped at equal intervals. These are the final phase noise measurement values ​​and amplitude modulation noise measurement values.

[0011] Secondly, in order to achieve the above objectives, the present invention discloses a phase noise measurement system based on vector network analyzer hardware, comprising: The data processing module is used to receive dual-channel ADC data, preprocess the dual-channel ADC data to obtain preprocessed baseband complex IQ data, perform phase analysis on the preprocessed baseband complex IQ data to obtain phase data, and perform cross-correlation and amplitude analysis on the phase data to obtain phase noise data. The data frequency modulation module is used to perform amplitude analysis on the preprocessed baseband complex IQ data to obtain amplitude data, perform dual-channel complex cumulative averaging on the amplitude data to obtain amplitude modulation noise data, and process the phase noise data and amplitude modulation noise data to obtain phase noise spectrum results and amplitude modulation noise spectrum results. The noise measurement module is used to perform peak detection and spurious detection on the phase noise spectrum results and amplitude modulation noise spectrum results to obtain spurious identification results. The spurious identification results are then spuriously removed to obtain the final phase noise measurement value and amplitude modulation noise measurement value.

[0012] In another aspect of the present invention, in order to achieve the above-mentioned objective, a terminal device is disclosed, including a memory, a processor, and a computer program stored in the memory and capable of running on the processor. The memory stores the computer program capable of running on the processor. When the processor loads and executes the computer program, it employs a phase noise measurement method based on vector network analyzer hardware as described above.

[0013] In another aspect of the present invention, in order to achieve the above-mentioned objective, a computer-readable storage medium is disclosed, wherein a computer program is stored in the computer program, and when the computer program is loaded and executed by a processor, a phase noise measurement method based on vector network analyzer hardware as described above is employed.

[0014] The beneficial effects of this invention are: This invention utilizes a vector network analyzer for measurement, saving instrument costs and eliminating the need to purchase a dedicated phase noise meter for measuring phase noise parameters. It also eliminates the need for a reference signal source, improving operational convenience. Employing the aforementioned phase noise measurement data processing method, it acquires high-precision phase difference information using a fully digital approach, with most functions performed in the digital domain, offering advantages such as low noise floor and high test repeatability. Furthermore, it can suppress amplitude modulation noise or extract amplitude modulation noise information. For a two-port vector network analyzer, it can perform dual-channel cross-correlation calculations, suppressing uncorrelated background noise in both channels. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Figure 1 This is a schematic diagram of the method flow of the present invention; Figure 2 This is a schematic diagram of the device connection and use of the present invention; Figure 3 This is a schematic diagram of the process of the present invention; Figure 4 This is a schematic diagram illustrating the implementation of the method of the present invention; Figure 5 This is a schematic diagram of the system structure of the present invention.

[0016] Figure 6 This is a diagram showing the effect of phase noise measurement results of the system of the present invention. Detailed Implementation

[0017] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0018] Example 1: like Figure 1 As shown, a phase noise measurement method based on vector network analyzer hardware includes the following steps: S101: Receive dual-channel ADC data, preprocess the dual-channel ADC data to obtain preprocessed baseband complex IQ data, perform phase analysis on the preprocessed baseband complex IQ data to obtain phase data, and perform cross-correlation and amplitude analysis on the phase data to obtain phase noise data. The dual-channel ADC data is obtained by post-processing the test signal using a vector network analyzer. The testing process of the vector network analyzer is as follows: Set the output RF output switch of the vector network analyzer to the off state, split the signal under test into two signals through the power divider, and input the two signals through the PORT1 and PORT2 test ports of the vector network analyzer, thereby realizing the hardware channel construction of the dual-channel cross-correlation digital phase noise measurement circuit. By acquiring the ADC data inside the vector network analyzer, the intermediate frequency signal after downconversion of the two signals can be obtained as the dual-channel ADC data.

[0019] The process of preprocessing the dual-channel ADC data involves digitally down-converting the acquired dual-channel ADC data, decimating and filtering the data according to the analyzed frequency offset range, and generating preprocessed baseband complex IQ data.

[0020] S102: Perform amplitude analysis on the preprocessed baseband complex IQ data to obtain amplitude data. Perform dual-channel complex cumulative averaging on the amplitude data to obtain amplitude modulation noise data. Process the phase noise data and amplitude modulation noise data to obtain phase noise spectrum results and amplitude modulation noise spectrum results. The process of performing cross-correlation and amplitude analysis on the phase data to obtain phase noise data: Frequency difference analysis is performed on the phase data to generate frequency difference compensation data for the digital frequency synthesizer module, which is used to offset the measurement error caused by frequency difference during phase noise measurement. Cross-correlation operation is performed on the phase data acquired by the dual-channel ADC. The FFT operator can accelerate the speed and efficiency of cross-correlation operation and generate phase noise data.

[0021] The process of processing phase noise data and amplitude modulation noise data to obtain phase noise spectrum results and amplitude modulation noise spectrum results includes: The phase noise data and amplitude modulation noise data are segmented, overlapped, and windowed by the spectrum estimation module, and then the power spectrum is estimated to finally obtain the phase noise spectrum result and amplitude modulation noise spectrum result.

[0022] S103: Perform peak detection and spurious detection on the phase noise spectrum results and amplitude modulation noise spectrum results to obtain spurious identification results. Perform spurious removal on the spurious identification results to obtain the final phase noise measurement value and amplitude modulation noise measurement value.

[0023] The process of obtaining the final phase noise measurement value and amplitude modulation noise measurement value includes: The phase noise spectrum and amplitude modulation noise spectrum output by the spectrum estimation module are generated by root mean square detection. According to the settings, they are then smoothed. The display point frequency is fixed, and the logarithmic frequency is stepped at equal intervals. These are the final phase noise measurement values ​​and amplitude modulation noise measurement values.

[0024] Specifically, the present invention will be further illustrated below through embodiments: Measurements based on a vector network analyzer save on instrument costs, eliminating the need to purchase a separate phase noise meter for measuring phase noise parameters; it also eliminates the need for a reference signal source, improving operational convenience; it acquires high-precision phase difference information using a fully digital method, with most functions performed in the digital domain, offering advantages such as low noise floor and high test repeatability; it can suppress amplitude modulation noise or extract amplitude modulation noise information; and it can perform dual-channel cross-correlation calculations on a two-port vector network analyzer, suppressing uncorrelated background noise in both channels.

[0025] The acquired dual-channel ADC data is digitally down-converted and then decimated and filtered to obtain the IQ baseband data of the test signal. Digital phase demodulation of the IQ baseband data yields the phase change information of the test signal. The frequency estimation module can then predict the actual intermediate frequency of the vector network analyzer (VNA) system based on the phase information of the test signal, thereby enabling frequency compensation for the digital frequency synthesizer module.

[0026] The phase linearity obtained from the two ADC data channels is cross-correlated and then subjected to FFT operation to further eliminate noise introduced by the measurement channel. The spectrum estimation module then reduces the amount of system data storage, which reduces the complexity of data processing and improves the speed of data processing, while ensuring the wide bandwidth and high resolution spectrum display results required by the system.

[0027] Depending on the display and analysis needs, the amplitude modulation noise can be extracted from the ADC sampled data through the amplitude demodulation module, and further spurious identification and data smoothing can be performed on the phase noise measurement data.

[0028] like Figure 6 As shown, the phase data from the two ADC channels, namely PORT1 and PORT2, are cross-correlated using FFT to obtain the "phase noise (after smoothing) of the dual-channel cross-correlation measurement". This is approximately 5log10(N) times better than the phase noise measured by a single channel using the vector network gauging system, where N is the number of cross-correlation measurements.

[0029] Example 2: To achieve the above objective, such as Figure 5 As shown, based on Embodiment 1, this invention discloses a phase noise measurement system based on vector network analyzer hardware, characterized in that it includes: Data processing module 11 is used to receive dual-channel ADC data, preprocess the dual-channel ADC data to obtain preprocessed baseband complex IQ data, perform phase analysis on the preprocessed baseband complex IQ data to obtain phase data, and perform cross-correlation operation and amplitude analysis on the phase data to obtain phase noise data. The data frequency modulation module 12 is used to perform amplitude analysis on the preprocessed baseband complex IQ data to obtain amplitude data, perform dual-channel complex cumulative averaging on the amplitude data to obtain amplitude modulation noise data, and process the phase noise data and amplitude modulation noise data to obtain phase noise spectrum results and amplitude modulation noise spectrum results. The noise measurement module 13 is used to perform peak detection and spurious judgment on the phase noise spectrum results and amplitude modulation noise spectrum results to obtain spurious identification results, and to remove spurious noise from the spurious identification results to obtain the final phase noise measurement value and amplitude modulation noise measurement value.

[0030] Based on the same inventive concept, this invention also provides a computer device, comprising: one or more processors, and a memory for storing one or more computer programs; the programs include program instructions, and the processor executes the program instructions stored in the memory. The processor may be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. It is the computing and control core of the terminal, used to implement one or more instructions, specifically for loading and executing one or more instructions stored in a computer storage medium to implement the above-described method.

[0031] It should be further explained that, based on the same inventive concept, the present invention also provides a computer storage medium storing a computer program, which, when executed by a processor, performs the above-described method. This storage medium can be any combination of one or more computer-readable media. The computer-readable medium can be a computer-readable signal medium or a computer-readable storage medium. The computer-readable storage medium can be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples of computer-readable storage media (a non-exhaustive list) include: an electrical connection having one or more wires, a portable computer disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage device, magnetic storage device, or any suitable combination thereof. In the present invention, the computer-readable storage medium can be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, apparatus, or device.

[0032] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this disclosure. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0033] The foregoing has shown and described the basic principles, main features, and advantages of this disclosure. Those skilled in the art should understand that this disclosure is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of this disclosure. Various changes and modifications can be made to this disclosure without departing from its spirit and scope, and all such changes and modifications fall within the scope of this disclosure as claimed.

Claims

1. A phase noise measurement method based on vector network analyzer hardware, characterized in that, The method includes the following steps: Receive dual-channel ADC data, preprocess the dual-channel ADC data to obtain preprocessed baseband complex IQ data, perform phase analysis on the preprocessed baseband complex IQ data to obtain phase data, and perform cross-correlation and amplitude analysis on the phase data to obtain phase noise data. Amplitude analysis is performed on the preprocessed baseband complex IQ data to obtain amplitude data. Dual-channel complex cumulative averaging is performed on the amplitude data to obtain amplitude modulation noise data. The phase noise data and amplitude modulation noise data are processed to obtain phase noise spectrum results and amplitude modulation noise spectrum results. Peak detection and spurious detection are performed on the phase noise spectrum results and amplitude modulation noise spectrum results to obtain spurious identification results. Spurious removal is then performed on the spurious identification results to obtain the final phase noise measurement value and amplitude modulation noise measurement value.

2. The phase noise measurement method based on vector network analyzer hardware according to claim 1, characterized in that, The dual-channel ADC data is obtained by post-processing the test signal using a vector network analyzer.

3. The phase noise measurement method based on vector network analyzer hardware according to claim 2, characterized in that, The testing process of the vector network analyzer: Set the output RF output switch of the vector network analyzer to the off state, split the signal under test into two signals through the power divider, and input the two signals through the PORT1 and PORT2 test ports of the vector network analyzer, thereby realizing the hardware channel construction of the dual-channel cross-correlation digital phase noise measurement circuit. By acquiring the ADC data inside the vector network analyzer, the intermediate frequency signal after downconversion of the two signals can be obtained as the dual-channel ADC data.

4. The phase noise measurement method based on vector network analyzer hardware according to claim 1, characterized in that, The process of preprocessing the dual-channel ADC data involves digitally down-converting the acquired dual-channel ADC data, decimating and filtering the data according to the analyzed frequency offset range, and generating preprocessed baseband complex IQ data.

5. The phase noise measurement method based on vector network analyzer hardware according to claim 1, characterized in that, The process of performing cross-correlation and amplitude analysis on the phase data to obtain phase noise data: Frequency difference analysis is performed on the phase data to generate frequency difference compensation data for the digital frequency synthesizer module, which is used to offset the measurement error caused by frequency difference during phase noise measurement. Cross-correlation operation is performed on the phase data acquired by the dual-channel ADC. The FFT operator can accelerate the speed and efficiency of cross-correlation operation and generate phase noise data.

6. The phase noise measurement method based on vector network analyzer hardware according to claim 1, characterized in that, The process of processing phase noise data and amplitude modulation noise data to obtain phase noise spectrum results and amplitude modulation noise spectrum results includes: The phase noise data and amplitude modulation noise data are segmented, overlapped, and windowed by the spectrum estimation module, and then the power spectrum is estimated to finally obtain the phase noise spectrum result and amplitude modulation noise spectrum result.

7. The phase noise measurement method based on vector network analyzer hardware according to claim 1, characterized in that, The process of obtaining the final phase noise measurement value and amplitude modulation noise measurement value includes: The phase noise spectrum and amplitude modulation noise spectrum output by the spectrum estimation module are generated by root mean square detection. According to the settings, they are then smoothed. The display point frequency is fixed, and the logarithmic frequency is stepped at equal intervals. These are the final phase noise measurement values ​​and amplitude modulation noise measurement values.

8. A phase noise measurement system based on vector network analyzer hardware, characterized in that, include: The data processing module is used to receive dual-channel ADC data, preprocess the dual-channel ADC data to obtain preprocessed baseband complex IQ data, perform phase analysis on the preprocessed baseband complex IQ data to obtain phase data, and perform cross-correlation and amplitude analysis on the phase data to obtain phase noise data. The data frequency modulation module is used to perform amplitude analysis on the preprocessed baseband complex IQ data to obtain amplitude data, perform dual-channel complex cumulative averaging on the amplitude data to obtain amplitude modulation noise data, and process the phase noise data and amplitude modulation noise data to obtain phase noise spectrum results and amplitude modulation noise spectrum results. The noise measurement module is used to perform peak detection and spurious detection on the phase noise spectrum results and amplitude modulation noise spectrum results to obtain spurious identification results. The spurious identification results are then spuriously removed to obtain the final phase noise measurement value and amplitude modulation noise measurement value.

9. A terminal device, comprising a memory, a processor, and a computer program stored in the memory and capable of running on the processor, characterized in that, The memory stores a computer program that can run on the processor. When the processor loads and executes the computer program, it employs a phase noise measurement method based on vector network analyzer hardware as described in any one of claims 1 to 7.

10. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is loaded and executed by the processor, it employs a phase noise measurement method based on vector network analyzer hardware as described in any one of claims 1 to 7.

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