Measurement system capable of displaying signal spectral line frequency power data in real time

Abstract

The invention relates to the technical field of electronic circuits, in particular to a measuring system capable of displaying signal spectral line frequency power data in real time, which comprises a pre-programmable attenuator, a pre-amplifier, a frequency mixer, a local oscillation source, an intermediate-frequency low-pass filter, a logarithmic detector, an analog-to-digital converter, an MCU (Microprogrammed Control Unit) and a TFT (Thin Film Transistor) screen display. A signal feeding device realizes gain control through an attenuator and a pre-amplifier and then is fed into a frequency mixer to realize signal frequency mixing output with a frequency sweeping signal generated by a local oscillation source, a lower frequency mixing signal is selected through a low-pass filter with a proper transmission band, and signal detection work is completed by using a logarithmic detector. Under the acquisition of the analog-to-digital converter, the power value of the signal is measured through a calibrated multi-time power function fitting curve built in the MCU. And finally, the device performs positive peak value sampling and certain frequency point compression by the MCU after signal detection, a frequency value of a signal to be measured is obtained by combining a sweep frequency, and measurement contents are uniformly converted to a TFT screen for parameter and spectral line display.

Description

Technical Field

[0001] The present invention relates to the technical field of electronic circuits, and in particular to a measurement system capable of displaying signal spectrum line frequency power data in real time. Background Art

[0002] With the rapid advancement of electronic products, we've noticed that they're becoming increasingly smaller, while the number of different microchip models on a single PCB is increasing. Signal traces with varying transmission speeds are becoming increasingly dense, making it increasingly difficult to overcome electromagnetic interference. In addition to electromagnetic interference generated by the products themselves, electromagnetic interference between devices is ubiquitous. The increasing use of various electrical devices is also impacting the electromagnetic environment. The increasing density of electronic and electrical devices within limited spaces, coupled with their increasing power, is leading to an increasingly crowded radio spectrum and a deteriorating electromagnetic environment. Summary of the Invention

[0003] The purpose of the present invention is to provide a measurement system that can display signal spectrum line frequency power data in real time. Through a sweeping frequency source and a mixing device, combined with a logarithmic detector, and using a microprocessor's software algorithm fitting control, it can ensure good measurement accuracy while reducing the complexity of the software algorithm computing power and the redundant structure of the hardware.

[0004] To achieve the above-mentioned objectives, the present invention provides a measurement system that can display signal spectrum line frequency power data in real time, including a pre-programmable attenuator, a preamplifier, a mixer, a local oscillator, a low-pass filter, a logarithmic detector, an analog-to-digital converter, an MCU microcontroller and a TFT screen display. The pre-programmable attenuator, the mixer, the low-pass filter, the logarithmic detector, the analog-to-digital converter, the MCU microcontroller and the TFT screen display are electrically connected in sequence, and the local oscillator is connected to the above-mentioned circuit from one end of the mixer and passes through a bandpass filter to perform certain harmonic suppression before being connected.

[0005] The external signal to be measured is connected to the system through the system's T-type matching SMA interface, or a near-field probe / antenna with an impedance of 50 ohms is hard-connected to the system through the SMA head.

[0006] The programmable pre-attenuator realizes precise attenuation control of the signal in 0.25dB unit steps, and achieves a maximum signal attenuation of 31.75dB in a digitally controlled manner.

[0007] The mixer adopts the IAM81008 model, and an independent voltage regulator is set to provide the working voltage to ensure the mixing linearity and mixing gain.

[0008] The local oscillator uses the ADF4351 frequency synthesizer chip from Analog Devices, which is used to output a signal with a wide frequency range.

[0009] The low-pass filter adopts a Butterworth structure, the filter order is set to 4th order, the passband is set to 300KHz, the stopband is set to 800KHz, the stopband gain attenuation reaches -40dB, and the input and output adopt 50 ohm impedance matching.

[0010] The output voltage of the logarithmic detector is V out The average power of the signal P in The logarithmic relationship is as follows:

[0011]

[0012] Where K is a constant coefficient, which is determined by the sensitivity of the detector to the input power; P0 is the reference power, 1mW corresponding to 0dBm is usually used as the reference power point, and V0 is the corresponding voltage; V off is the offset voltage value.

[0013] The MCU microcontroller uses the STM32F401 model, and during the signal processing, the internal ADC module is called to perform level acquisition with an accuracy of 12 bits.

[0014] The ADC module clock frequency is divided into the highest configuration of 84MHz, and the sampling period is set to the fastest three cycles. The ADC conversion time formula is as follows:

[0015] T conv =T sampling +T conversion

[0016] Where T sampling is the sampling time, which is 3 cycles, T conversion The conversion time is 12 bits, and the corresponding clock period is 12 cycles.

[0017] The present invention provides a measurement system capable of displaying signal spectrum line frequency power data in real time. The system comprises a pre-programmable attenuator, a preamplifier, a mixer, a local oscillator, an intermediate frequency low-pass filter, a logarithmic detector, an analog-to-digital converter (ADC), an MCU (microcontroller), and a TFT screen display. An interference signal is input via an external antenna or detection device and first passes through the pre-programmable attenuator, where the attenuation coefficient is controlled by the MCU to ensure that the detected input signal power is within the linear range processed by various components in the system. The signal then enters the mixer and is mixed with a frequency-sweep signal continuously input from the local oscillator to generate a mixed output. A low-pass filter with an appropriate passband selects the down-mixed signal. A logarithmic detector then performs signal detection, converting the AC or pulse signal into a valid DC level signal. Finally, the power of the interference signal can be successfully measured using the ADC. The frequency value of the signal can also be calculated by reading the frequency-sweep step data from the local oscillator. The structural modules of the present invention are simple, compact and efficient in design, ensuring that the device has a relatively low cost of use and has the advantage of being portable and adaptable to a wide range of complex working environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0019] Figure 1 It is a schematic diagram of the principle of a measurement system capable of displaying signal spectrum line frequency power data in real time according to the present invention.

[0020] Figure 2 It is a schematic diagram of an original signal measured by a frequency sweeping principle simulation embodiment of a measurement system capable of displaying signal spectrum line frequency power data in real time according to the present invention.

[0021] Figure 3 It is a schematic diagram of a local oscillator signal with linear frequency variation in an embodiment of a frequency sweeping principle simulation of a measurement system capable of displaying signal spectrum line frequency power data in real time according to the present invention.

[0022] Figure 4 This is a schematic diagram of a frequency-selective signal spectrum in a frequency sweeping principle simulation embodiment of a measurement system capable of displaying signal spectrum line frequency power data in real time according to the present invention.

[0023] Figure 5 The present invention is a schematic diagram of a loop filter topology structure of a local oscillator source fast locking mode of a measurement system capable of displaying signal spectrum line frequency power data in real time.

[0024] Figure 6 The present invention is a schematic diagram of a simulation structure of an intermediate frequency low-pass filter design of a measurement system capable of displaying signal spectrum line frequency power data in real time.

[0025] Figure 7 The present invention is a schematic diagram of S-parameter simulation of the intermediate frequency low-pass filter design of a measurement system capable of displaying signal spectrum line frequency power data in real time.

[0026] Figure 8 It is a schematic diagram of the minimum sensitivity ratio of multiple frequency band tests actually measured by the present invention.

[0027] Figure 9 It is a schematic diagram comparing signal measurement record curves of multiple groups of different frequency points and different power levels in a physical embodiment of the present invention.

[0028] Figure 10 This is a schematic diagram of the measured spectrum of the signal of the present invention, (a~f) represent from 200MHz to 2200MHz respectively. DETAILED DESCRIPTION

[0029] The following describes embodiments of the present invention in detail, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and are not to be construed as limiting the present invention.

[0030] See also Figure 1 The present invention provides a measurement system capable of displaying signal spectrum line frequency power data in real time, comprising a pre-programmable attenuator, a preamplifier, a mixer, a local oscillator, a low-pass filter, a logarithmic detector, an analog-to-digital converter, an MCU microcontroller, and a TFT screen display. The pre-programmable attenuator, the mixer, the low-pass filter, the logarithmic detector, the analog-to-digital converter, the MCU microcontroller, and the TFT screen display are electrically connected in sequence. The local oscillator is connected to the above-mentioned circuit from one end of the mixer and passes through a bandpass filter to perform certain harmonic suppression before being connected.

[0031] The signal transmission process of the present invention is as follows: First, it passes through a pre-programmable attenuator, whose attenuation coefficient is controlled by the MCU microcontroller to ensure that the signal power of the detection input is within the linear range processed by various components of the system. The signal is then sent to the mixer and mixed with the swept frequency signal continuously sent by the local oscillator to achieve signal output. Then, a low-pass filter with an appropriate passband selects the down-mixed signal. The logarithmic detector is then used to complete the signal detection work, converting the AC signal or pulse signal into an effective DC level signal. Finally, under the acquisition of the analog-to-digital converter, the power value of the interference signal can be successfully measured. By reading the swept frequency step data of the local oscillator, the frequency value of the signal can also be converted.

[0032] The present invention is further described below in conjunction with the design principles and simulation examples:

[0033] 1. Theoretical analysis of swept frequency measurement

[0034] In this invention, a local oscillator (LO) is designed to continuously scan a specific frequency band and input it into a mixer. Using the frequency information from the LO output, the frequency of the signal under test can be determined without resorting to complex DSP algorithms. Assuming x(t) is the signal under test and y(t) is the LO signal, the formula models are as follows:

[0035] x(t)=Acos(2πf x t+φ x )

[0036] y(t)=B cos(2πf L0 t+φ L0 )

[0037] A and B are the amplitudes of the measured signal and the local oscillator signal respectively, and the corresponding f x and φ x , f L0 and φ L0 are the frequency and initial phase of the signal to be measured, and the frequency and initial phase of the local oscillator signal. The two signals are sent to the mixer to multiply them. The expression of the multiplied signal z(t) is as follows:

[0038] z(t)=Acos(2πf x t+φ x )·B cos(2πf L0 t+φ L0 )

[0039] From the changed theoretical formula, we can know that there are two frequency signals after mixing, namely: |f x -f L0 | and |f x +f L0|. The low-frequency signal is filtered out through a low-pass filter |f x -f L0 |, assuming that the impulse response of the low-pass filter is h(t), after inputting the mixing signal z(t), according to the convolution theory of the signal, the expressions of the filtered low-frequency signals can be obtained as follows:

[0040]

[0041] From the analysis of the formula theory, we know that by setting the local oscillator source to a certain step accuracy to change the frequency of the local oscillator source output signal, the closer the local oscillator frequency sweep signal is to the signal to be measured, the larger the signal amplitude output by the filter will be. At this time, it can be considered that the frequency of the local oscillator source output signal at the time when the filter output signal amplitude is the largest under a certain accuracy error is the frequency value of the signal to be measured. The principle of frequency sweep measurement is simply simulated by MATLAB, and the simulation steps are shown in the figure below. Figures 2 to 4 shown.

[0042] From the simulated spectrum image, it can be seen that the smaller the difference frequency between the swept signal and the original signal, the greater the power amplitude of the down-converted signal after the mixing filter output, and the closer the frequency of the swept signal is to the original signal to be measured.

[0043] 2. Logarithmic detection measurement theory analysis

[0044] Considering that EMI detection requires a large power detection dynamic range and good accuracy and linearity, the logarithmic detector is a suitable choice. Similarly, establish a signal model v in (t), the process of logarithmic detection measurement is analyzed theoretically, and its expression is as follows:

[0045] v in (t) = V in cos(2πft+φ)

[0046] In the formula, V in is the peak voltage of the input signal, f and φ are the frequency and initial phase of the signal respectively. According to the relationship between power and voltage, we can know that the peak voltage v in The relationship between it and the average power value is as follows:

[0047]

[0048] P in is the average power of the signal, and R can be regarded as the equivalent resistance on the signal transmission line.

[0049] The output of the logarithmic detector is generally a voltage value, which can be assumed to be V out The average power P mentioned in the above formula is in , also known as input power, which is related to the input voltage Vout The logarithmic relationship for is usually as follows:

[0050]

[0051] Where K is a constant coefficient, which is determined by the sensitivity of the detector to the input power. P0 is the reference power, 1mW corresponding to 0dBm is usually used as the reference power point, and V0 is the corresponding voltage. off is the offset voltage value. By substituting the relationship between power and output voltage into the relationship between peak voltage and power and utilizing the logarithmic calculation properties, the formula can be further expanded into a logarithmic relationship with respect to voltage:

[0052] V out =2Klog 10 (V in )-2Klog 10 (V0)+V off

[0053] In order to obtain an expression that only retains the peak voltage of the input and the detection output voltage, a new constant V ref Replacing the last two terms of the formula, we finally get the following relationship:

[0054] V ref =-2Klog 10 (V0)+V off

[0055] V out =2Klog 10 (V in )+V ref

[0056] Constant term V ref This can be thought of as the voltage value of the detector's noise floor. From the final formula, we know that using logarithmic detection can effectively convert the input signal's peak signal into an output voltage value with a wide dynamic range and strong linearity, greatly simplifying subsequent data processing.

[0057] 3. Acquisition speed analysis

[0058] Common sense tells us that the fastest frequency change the human eye can accept is around 20 milliseconds. To achieve a better visual effect of spectrum analysis for electromagnetic interference analysis, the measurement speed of a single frequency point should be less than or equal to 1 millisecond. This speed is primarily determined by the ADC acquisition speed, the local oscillator signal conversion speed, and the display speed. First, we analyze the acquisition speed of the MCU's built-in ADC module, which uses 12-bit acquisition accuracy. The ADC clock frequency divider uses the highest configuration of 84MHz, and its sampling period is set to a minimum of three cycles. The ADC conversion time formula is as follows:

[0059] T conv =T sampling +T conversion

[0060] Where T sampling is the sampling time, which is 3 cycles, T conversion The conversion time depends on the accuracy of the ADC. 12 bits means 12 cycles. The total conversion time of the ADC is 15 clock cycles. When the clock division factor is 1, each clock cycle on the ADC is the inverse of 84MHz. It is easy to deduce that each clock cycle is about 12ns, and the shortest time required for ADC acquisition is 180ns. After the ADC acquires and processes the data, it uses the DMA transmission method. The transmission time here can be ignored. The communication protocol used in the display part is SPI, which uses a conventional stable divided clock, that is, 8 divisions. The clock cycle f SPI as follows:

[0061]

[0062] If an 8-bit data frame format is used for communication, combined with the SPI clock cycle, the communication time for one byte is approximately 0.77µs. A single display update of 100 bytes takes 77µs. Finally, factoring in the 10µs time it takes to read the ADC sampled data, we find that, ignoring the local oscillator (LO) time, the device's acquisition time is no more than 100µs. Conventional local oscillator sources on the market typically have single-sweep times of less than 600µs. This analysis confirms that the acquisition speed meets the requirements.

[0063] 4. Local oscillator design analysis

[0064] The design requirements of the local oscillator source are to be able to output a signal with a wide frequency range, and at the same time, the frequency drift of the output signal is low, and it has the characteristics of long-term stable operation. It uses the ADF4351 frequency synthesizer chip from ADI. The frequency synthesis output of this chip can reach 4000MHz, and the output amplitude can be adjusted at multiple levels. The 10MHz active crystal oscillator provides a stable peripheral clock signal to the local oscillator source. The speed requirement for the ADF4351 single-frequency point scanning is high, and its fast locking mode can be used. The fast locking mode requires changing the conventional loop filter topology of the SW pin in the peripheral circuit, changing the filter structure from a higher-order to a lower-order, increasing the bandwidth, and sacrificing a certain amount of noise performance to increase the speed of switching the locking frequency. The filter topology is as follows Figure 5 As shown in the figure, the designed resistors R1 and R1A are set to 30 ohms and 91 ohms respectively, satisfying the ratio of 1:3.

[0065] 5. Filter design analysis

[0066] The intermediate frequency filter adopts a passive low-pass filter structure with a Butterworth structure. The filter order is designed to be 4th order, the passband is designed to be 300KHz, the stopband is set to 800KHz, and the input and output use 50 ohm impedance matching. The ADS simulation software initially generated the S21 parameter curve of the LC filter structure. At the end of the passband at 800KHz, the gain attenuation reached -30.51dB. However, the S21 parameter has a large gain fluctuation of more than 3dB within the passband range, which will cause difficulties in signal data processing. Considering the difficulties in actual production and device selection, the capacitance values ​​of C1 and C2 were adjusted from 6.86nF and 16.56nF to 6.8nF and 15nF respectively; the inductors L1 and L2 were adjusted from 41.4uH and 17.1uH to 40uH and 20uH respectively; and the capacitor C3 was adjusted from 10nF to 5nF. Under the premise of ensuring that the gain attenuation in the stop band 800KHz is slightly reduced from -30dB to -28dB, the simulation results show that the S21 parameter has a small fluctuation within the band (within 1dB). The final filter design structure and S parameter simulation diagram are shown as follows: Figure 6 , Figure 7 shown.

[0067] 6. System program control design analysis

[0068] The microcontroller, an STM32F401, controls the entire test system. For signal processing, the microcontroller uses an internal ADC module to acquire voltage levels with 12-bit accuracy. ADC conversions are triggered by software within the controller's internal registers, set to a frequency of three cycles. The ADC requires fast data storage via another hardware resource, the DMA transfer channel, which utilizes a 16-bit integer array for storing collected data. The microcontroller also uses a timer clocked from the same clock source as the ADC hardware resource. By configuring a preset value and a frequency division factor, the timer is set to poll the ADC sample value every 10µs. The sampled values ​​are then fed into a sampling curve fitted with a multi-power function to convert the sampled values ​​into output power. To minimize measurement errors within the software algorithm, the final output value undergoes a sliding average of fifty sample values ​​and a positive peak sampling algorithm.

[0069] Furthermore, the present invention is further illustrated by way of practical examples:

[0070] During the physical test, the test system (hereinafter referred to as the measurement device or device) consists of an upper and lower board, secured together by an alloy metal housing. The upper board houses the main controller, TFT display, and charging module, while the lower board houses the signal processing front-end, including the attenuator, local oscillator, mixer, filter, detector, and power supply module. An RF signal source feeds single-frequency signals of varying power directly into the system via a hard-wired SMA connector. The signal frequency range is set between 100MHz and 4000MHz. The test system's TFT display displays the spectrum of the swept frequency band while also updating the frequency and power values ​​of the real-time signal.

[0071] Continuously input a single-frequency signal within 4GHz from low to high frequency, and continuously reduce the power value of the input signal until the signal is about to be submerged in the bottom noise of the measurement device. The power value signal measured at this time is recorded and can be considered as the minimum power sensitivity of the device under this frequency point. The data is plotted into a chart for comparison as shown below Figure 7 As shown, the horizontal axis is the frequency value and the vertical axis is the power value. It can be seen that the minimum sensitivity curve of the device is relatively flat, without large fluctuations, and the error is relatively stable.

[0072] After analyzing the sensitivity, we will continue to test and analyze the overall flatness of the device's operating frequency band. Connect the signal source to the measurement device and input multiple signals of different power levels at the same frequency point for recording. The measurement records of multiple groups of signals of different power levels at different frequencies are plotted into a curve as shown below. Figure 8 As shown, the horizontal axis represents the actual output power value, and the vertical axis represents the measured power value. The slopes of all the different frequency group curves in the figure converge to 1, indicating that the device maintains high accuracy over a wide range of power levels from +20dBm to -60dBm. It also shows that the device's performance is relatively flat across the entire 4G operating frequency band, demonstrating good continuous operation. Next, we tested the access of arbitrary single-frequency signals at different power levels. The measured frequency values ​​for multiple signal groups are compared with the actual values ​​in the table below, demonstrating the device's relatively accurate frequency measurement.

[0073]

[0074]

[0075] In this embodiment, electronic interference detection data comparison is also performed.

[0076] The detection input front end of the device is a T-type matching interface. After conversion and matching connection with the NFP-3 series near-field probe produced by RIGOL, a conventional PCB industrial board with unshielded signal lines was selected for EMI detection. The detection results finally showed that the location of the electromagnetic leakage was near the crystal oscillator source of the PCB industrial board. The fundamental frequency of the leaked electromagnetic signal was 200MHz, and the harmonic components were 600MHz, 1000MHz, 1400MHz, 1800MHz, and 2200MHz. The power values ​​measured by the EMI measurement device were -35.0dBm, -43.3dBm, -48.4dBm, -54.2dBm, -55.7dBm, and -58.3dBm respectively. The actual measured spectrum of the device is shown in the figure below. Figure 10 As shown in (a~f).

[0077] The measurement results of the measurement device and the real-time spectrum analyzer ESA5065 are tabulated below. Comparison shows that the detected signals are identical, demonstrating that the device can accurately detect EMI while also offering significant advantages in terms of lightweight design for electromagnetic leakage detection.

[0078]

[0079] In summary, the measurement system capable of displaying signal spectrum line frequency power data in real time of the present invention can realize the measurement of electromagnetic interference signals through an external electromagnetic probe. The signal frequency range detected by the device is relatively wide, ranging from 100MHz to 4000MHz, and the power dynamic range can reach -60dBm from +20dBm, with the measurement error maintained at ±0.5dB. The device has a good spectrum line display interface, and the operation of the entire device is controlled by a single button, which can be a very convenient work aid for the users of the device. The structural module design of each part of the device is simple, compact and efficient, ensuring that the cost of using the device is relatively low. What's more, the cross-sectional area of ​​the entire device does not exceed the size of an ordinary adult's palm, and it has a significant portability advantage in size, which can adapt to a wide range of complex working environments.

[0080] The above disclosure is merely one or more preferred embodiments of the present invention, and certainly cannot be used to limit the scope of the present invention. A person skilled in the art can understand that all or part of the processes of the above embodiments and equivalent changes made in accordance with the claims of the present invention still fall within the scope of the invention.

Claims

1. A measurement system capable of displaying signal spectrum line frequency power data in real time, characterized in that: The system comprises a pre-programmable attenuator, a preamplifier, a mixer, a local oscillator, an intermediate frequency low-pass filter, a logarithmic detector, an analog-to-digital converter, an MCU microcontroller and a TFT screen display. The pre-programmable attenuator, the preamplifier, the mixer, the low-pass filter, the logarithmic detector, the analog-to-digital converter, the MCU microcontroller and the TFT screen display are electrically connected in sequence. The local oscillator is connected to the above circuit from one end of the mixer and passes through a bandpass filter before being connected.

2. The measurement system capable of displaying signal spectrum line frequency power data in real time according to claim 1, characterized in that: The external signal to be measured is connected to the system through the system's T-type matching SMA interface, or a near-field probe / antenna with an impedance of 50 ohms is hard-connected to the system through the SMA head.

3. The measurement system capable of displaying signal spectrum line frequency power data in real time according to claim 2, characterized in that: The programmable pre-attenuator achieves precise attenuation control of the signal in 0.25dB unit steps, and achieves a maximum signal attenuation of 31.75dB in a digitally controlled manner.

4. The measurement system capable of displaying signal spectrum line frequency power data in real time according to claim 3, characterized in that: The mixer adopts the IAM81008 model, and an independent voltage regulator is set to provide the working voltage to ensure the mixing linearity and mixing gain.

5. The measurement system capable of displaying signal spectrum line frequency power data in real time according to claim 4, characterized in that: The local oscillator uses the ADF4351 frequency synthesizer chip from Analog Devices, which is used to output a signal with a wide frequency range.

6. The measurement system capable of displaying signal spectrum line frequency power data in real time according to claim 5, characterized in that: The low-pass filter adopts a Butterworth structure, the filter order is set to 4th order, the passband is set to 300KHz, the stopband is set to 800KHz, the stopband gain attenuation reaches -40dB, and the input and output adopt 50 ohm impedance matching.

7. The measurement system capable of displaying signal spectrum line frequency power data in real time according to claim 6, characterized in that: The output voltage V of the logarithmic detector out The average power of the signal P in The logarithmic relationship is as follows: Where K is a constant coefficient, which is determined by the sensitivity of the detector to the input power; P0 is the reference power, 1mW corresponding to 0dBm is usually used as the reference power point, and V0 is the corresponding voltage; V off is the offset voltage value.

8. The measurement system capable of displaying signal spectrum line frequency power data in real time according to claim 7, characterized in that: The MCU microcontroller uses the STM32F401 model. During the signal processing process, the internal ADC module is called to perform level acquisition with an accuracy of 12 bits.

9. The measurement system capable of displaying signal spectrum line frequency power data in real time according to claim 8, characterized in that: The ADC module clock frequency is divided into the highest configuration of 84MHz, and its sampling period is set to the fastest three cycles. The ADC conversion time formula is as follows: T conv =T sampling +T conversion Where T sampling is the sampling time, which is 3 cycles, T conversion The conversion time is 12 bits, and the corresponding clock period is 12 cycles.

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