Electromagnetic narrow pulse high-precision power measurement system and method
By employing full-temperature calibration and digital detection methods, combined with a high-sampling-rate AD converter and an internal calibration source, the problem of poor accuracy in narrow-pulse microwave signal power measurement has been solved, achieving high-precision measurement over a wide temperature range, suitable for both military and civilian applications.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-26
- Publication Date
- 2026-04-07
AI Technical Summary
Traditional electromagnetic pulse signal power measurement methods are inaccurate for narrow pulse microwave signals and are sensitive to temperature changes. Conventional power meter products have long rise times and limited application scenarios.
The method of full-temperature calibration + digital detection is adopted. A high sampling rate AD converter and an internal calibration source are used, combined with a standard horn antenna and microwave power measurement equipment. Signal processing is performed through calibration and measurement channels to eliminate the influence of temperature on the measurement.
It improves the accuracy and application scenarios of narrow pulse microwave signal power measurement, is suitable for temperature ranges from -20 to 60°C, and is applicable to military and civilian applications.
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Figure CN121805671A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of microwave alarm technology, specifically an electromagnetic narrow pulse high-precision power measurement system and method. Background Technology
[0002] Traditional electromagnetic pulse signals are generally measured using detectors. This traditional power measurement method is limited by the characteristics of the devices, resulting in poor accuracy in measuring the power of narrow pulse microwave signals. It is also sensitive to temperature changes. Conventional power meters have a rise time greater than 15ns and are applicable to temperatures of 20~25℃, limiting their application scenarios. Summary of the Invention
[0003] The purpose of this invention is to provide a high-precision electromagnetic narrow-pulse power measurement system and method. The aim is to improve the accuracy of narrow-pulse microwave signal power measurement by using a "full-temperature calibration + digital detection" method, employing a high sampling rate AD converter to ensure the number of narrow-pulse power measurement points, and using an internal calibration source to eliminate the influence of temperature on power measurement. This solves the problem of poor accuracy in narrow-pulse signal power measurement and the limitation of existing methods to testing only under normal temperature conditions, greatly improving the accuracy of power measurement and expanding its application scenarios.
[0004] The technical solution adopted in this invention includes: An electromagnetic narrow pulse high-precision power measurement system is provided, which includes a standard horn antenna and a microwave power measurement device, and the microwave power measurement device and the standard horn antenna are connected by an RF cable. The microwave power measurement equipment is equipped with a microwave module and a digital processing module; The microwave module is equipped with one calibration channel and one measurement channel. A thermistor is set on the microwave module as a temperature measuring point to monitor the temperature of the microwave module in real time. The measurement channel digitally attenuates the microwave radio frequency signal or calibration signal received by the standard horn antenna and mixes it to obtain the intermediate frequency signal; the calibration channel amplifies the signal from the calibration source to generate a stable output calibration signal. The digital processing module performs AD acquisition on the intermediate frequency signal output by the microwave module. On the one hand, it calculates the calibration signal power, and on the other hand, it performs envelope detection on the pulse waveform that exceeds the threshold, thereby calculating the pulse signal power.
[0005] Optionally, the calibration channel consists of a frequency converter, an isolator, a filter, an attenuator, and a low-noise amplifier. It converts the crystal oscillator output signal from the calibration source and saturates the output signal through the low-noise amplifier, thereby generating a stable output calibration signal.
[0006] Optionally, the digital processing module can also package and transmit the pulse waveform data, and adjust the digitally controlled attenuator setting of the microwave module via a serial port.
[0007] Optionally, the output power of the calibration signal output by the calibration channel can be calibrated under full temperature conditions in the temperature chamber. The calibration test system is as follows: disconnect the connection between the calibration channel of the microwave module and the switch, and connect the calibration channel directly to the power meter. Place the calibration channel inside the temperature chamber and place the power meter outside the temperature chamber.
[0008] The measurement method of any of the electromagnetic narrow pulse high-precision power measurement systems of the present invention includes: S1 calibration source full-temperature output power calibration: Open the calibration channel in the microwave module, and set the attenuation value to... dB, record the temperature of the microwave module. If the temperature is ℃, then the output power of the calibration source is dBm; S2 Wired Link Insertion Loss Measurement: The insertion loss of the wired link is measured as follows: dB; S3 Calibration Signal Digital Acquisition and Processing: The digital processing module performs AD acquisition and data processing on the calibration signal to obtain the digital power of the calibration signal. dB; S4 Electromagnetic Narrow Pulse Signal Acquisition and Processing: Open the measurement channel, attenuation value is... dB; S5 Electromagnetic Narrow Pulse Power Calculation: The digital processing module performs AD acquisition and data processing on the calibration signal from the measurement channel to obtain the digital power of the calibration signal. dB; The pulse microwave power value, dBm, is: .
[0009] Optionally, in S5, the digital processing module performs down-conversion and low-pass filtering on the threshold-crossing pulse wave from the measurement channel, assuming the pulse signal waveform of the calibration signal is... Perform a frequency conversion on it: j is the complex number symbol, f is the mixing frequency, and t is the time. After low-pass filtering, take the absolute value: ; in, This is the filter amplitude reduction factor. These are the filter coefficients. This is a convolution operation.
[0010] Optionally, the full-temperature output power calibration of the S1 calibration source specifically includes: disconnecting the calibration channel of the microwave module from the switch and directly connecting the calibration channel to the power meter. The calibration channel is placed inside the temperature chamber, and the power meter is placed outside the temperature chamber. The temperature chamber starts at a high temperature and is set in 5°C increments. The output power of the calibration source is collected under full-temperature conditions, with each increment lasting 2 hours to ensure stable output. The correlation between the output power of the calibration source and the temperature is tested. By performing linear fitting, the output power value of the calibration source at different temperatures can be obtained.
[0011] The advantages of this invention are: Compared to traditional electromagnetic signal power measurement methods, this method is more suitable for power measurement of narrow-pulse microwave signals and eliminates the influence of temperature on power measurement. It provides strong support for both military and civilian applications, and has broad and significant application prospects and value. The electromagnetic narrow-pulse power measurement method disclosed in this invention includes the following steps: calibration of the full-temperature output power of the calibration source, measurement of wired link insertion loss, digital acquisition and processing of the calibration signal, acquisition and processing of the electromagnetic narrow-pulse signal, and calculation of the electromagnetic narrow-pulse power. Attached Figure Description
[0012] The accompanying drawings are provided to further illustrate the present disclosure and form part of the specification. They are used together with the following detailed description to explain the present disclosure, but do not constitute a limitation thereof. In the drawings: Figure 1 The steps of the electromagnetic narrow pulse power measurement method; Figure 2 Here is a block diagram of a microwave power measurement system; Figure 3 Flowchart for calibration test of full-temperature output power of calibration source; Figure 4 Waveform capture for electromagnetic narrow pulse signals; Figure 5 The time-domain waveform of the source signal after AD acquisition is used for calibration. Figure 6 Time-domain waveform of electromagnetic narrow pulse signal after AD acquisition; Figure 7 Electromagnetic narrow pulse signal envelope detection waveform diagram. Detailed Implementation
[0013] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.
[0014] To address the need for high-precision power measurement of narrow-pulse electromagnetic signals, this invention proposes a "full-temperature calibration + digital detection" method. Using a high-sampling-rate AD converter, it is applicable to narrow pulse widths of 10 ns and uses an internal calibration source to eliminate the influence of temperature on power measurement, ensuring a power measurement accuracy of 3.99% within a temperature range of -20 to 60℃. This method effectively solves the problem of poor accuracy and significant temperature-dependent effects in narrow-pulse electromagnetic signal power measurement, offering advantages such as high integration, large dynamic range, and high precision. Simulation and testing have effectively verified its practicality.
[0015] Combination Figure 2-3 The electromagnetic narrow-pulse high-precision power measurement system of the present invention includes a standard horn antenna and a microwave power measurement device, which are connected via an RF cable. The microwave power measurement device includes a microwave module and a digital processing module. The microwave module has one calibration channel and one measurement channel, and a thermistor is installed on the microwave module as a temperature measurement point to monitor the module temperature in real time. The measurement channel digitally attenuates the microwave RF signal or calibration signal received by the standard horn antenna and mixes it to obtain an intermediate frequency (IF) signal. The calibration channel amplifies the signal from the calibration source to generate a stable output calibration signal. The digital processing module performs AD acquisition on the IF signal output from the microwave module, calculating the calibration signal power and performing envelope detection on the pulse waveform that exceeds the threshold, thereby calculating the pulse signal power. More specifically, in conjunction with... Figure 2 The system consists of a standard horn antenna, a microwave power measurement device, and an RF cable. The electromagnetic pulse power measurement device internally incorporates a microwave module and a digital processing module. The microwave module primarily performs calibration, channel switching, digitally controlled attenuation, and mixing functions. The digital processing module handles AD conversion, digital processing, control, and data storage. The microwave module has two channels: a calibration channel and a measurement channel, which can be switched via a microwave switch. The microwave channel module is equipped with a thermistor to monitor the channel temperature in real time. The measurement channel digitally attenuates the microwave RF signal or calibration signal received by the standard horn antenna and mixes it to an intermediate frequency (IF). The calibration channel consists of a frequency converter, isolator, filter, attenuator, and low-noise amplifier. It converts the crystal oscillator output signal and saturates the output signal through the low-noise amplifier, thereby generating a stable calibration signal.
[0016] In this invention, the calibration channel consists of a frequency converter, an isolator, a filter, an attenuator, and a low-noise amplifier. It converts the crystal oscillator output signal from the calibration source and saturates the output signal through the low-noise amplifier, thereby generating a stable output calibration signal.
[0017] In this invention, the digital processing module can also package and transmit pulse waveform data, and adjust the digital attenuator setting of the microwave module via serial port.
[0018] In this invention, the output power of the calibration signal output by the calibration channel is calibrated under full-temperature conditions in a temperature chamber. The calibration test system is as follows: the calibration channel of the microwave module is disconnected from the switch, and the calibration channel is directly connected to the power meter. The calibration channel is placed inside the temperature chamber, and the power meter is placed outside the temperature chamber. The microwave power measurement device has a calibration channel internally designed, and the stable output signal generated by it is used as the true power value to calibrate the system. The calibration signal is limited by the microwave device and changes regularly with temperature. Therefore, the output power of the calibration signal output by the calibration source under full-temperature conditions can be calibrated in the temperature chamber, thereby eliminating the measurement error caused by temperature changes. The block diagram of the calibration source full-temperature output power calibration test system is as follows. Figure 3 As shown: The test obtained the relationship between the output power of the calibration source and the temperature. By performing linear fitting, the output power value of the calibration source at different temperatures can be obtained.
[0019] Combination Figure 1 The measurement method of the electromagnetic narrow pulse high-precision power measurement system of the present invention includes: S1 calibration source full-temperature output power calibration: Open the calibration channel in the microwave module, and set the attenuation value to... dB, record the temperature of the microwave module. If the temperature is ℃, then the output power of the calibration source is dBm; S2 Wired Link Insertion Loss Measurement: The insertion loss of the wired link is measured as follows: dB; S3 Calibration Signal Digital Acquisition and Processing: The digital processing module performs AD acquisition and data processing on the calibration signal to obtain the digital power of the calibration signal. dB; S4 Electromagnetic Narrow Pulse Signal Acquisition and Processing: Open the measurement channel, attenuation value is... dB; S5 Electromagnetic Narrow Pulse Power Calculation: The digital processing module performs AD acquisition and data processing on the calibration signal from the measurement channel to obtain the digital power of the calibration signal. dB; The pulse microwave power value is: .
[0020] In S5, the digital processing module performs down-conversion and low-pass filtering on the threshold-crossing pulse wave from the measurement channel. Assuming the pulse signal waveform of this calibration signal is... Perform a frequency conversion on it: j is the complex number symbol, f is the mixing frequency, and t is the time. After low-pass filtering, take the absolute value: ; in, This is the filter amplitude reduction factor. These are the filter coefficients. This is a convolution operation.
[0021] The full-temperature output power calibration of the S1 calibration source specifically includes: disconnecting the calibration channel of the microwave module from the switch and directly connecting the calibration channel to the power meter. The calibration channel is placed inside the temperature chamber, and the power meter is placed outside the temperature chamber. Starting from a high temperature, the temperature chamber is set in 5°C increments to collect the output power of the calibration source under full-temperature conditions. Each increment is paused for 2 hours to ensure the stability of the calibration source output. The correlation between the output power of the calibration source and the temperature is obtained by testing. Through linear fitting, the output power value of the calibration source at different temperatures can be obtained.
[0022] More specific steps are required for calculating pulsed microwave power, as follows: (1) Turn on the microwave power measurement equipment. After the equipment stabilizes, switch the switch to the calibration channel and set the digital attenuator attenuation value to be as follows. (Unit: dB) Record the temperature of the microwave module. Then the output power of the calibration source is ; (2) The insertion loss of the wired link was measured as follows: (Unit: dB); (3) Perform AD acquisition and data processing on the calibration signal to obtain the digital power of the calibration signal. ; (4) Switch the switch to the measurement channel and set the attenuation value of the digital attenuator to be [value missing]. (Unit: dB); (5) Perform AD acquisition and data processing on the calibration signal to obtain the digital power of the calibration signal. ; Assume the pulse signal waveform is Perform a frequency conversion on it: j is the complex number symbol, f is the mixing frequency, and t is the time. After low-pass filtering, take the absolute value. ; ; Waveforms before and after envelope detection are as follows Figure 4 Digital power of calibration signal This represents the average power of the signal within 3 dB of the peak value after envelope detection.
[0023] The pulse microwave power value (in dBm) is: All terms in the formula are converted to dB values for calculation.
[0024] To analyze the accuracy of power calculation for the aforementioned measurement system and method, the following method can be used: There are two main types of errors affecting pulse amplitude measurement: systematic errors and random errors. Systematic errors can be compensated for through calibration, so we will consider random errors here. The main factors affecting measurement accuracy are as follows: Power calculation accuracy includes: The effect of thermal noise on amplitude error is as follows: In the formula, The signal-to-noise ratio of a single pulse signal. To effectively accumulate pulse count; Data quantization error: In the formula, For measurement range; The number of quantization bits; (3) Calibration source output power calibration fitting error ; (4) Equipment measurement error ; (5) Cable insertion loss measurement error ; (6) Antenna pattern measurement error ; Total measurement error for: .
[0025] The solution of the present invention will be specifically described below with reference to specific embodiments: Example 1: Input parameters: Temperature at the measuring point: ℃; Fitted curve of calibration source output power as a function of temperature: ; Calibrate the CNC attenuation value: 15dB; Measured CNC attenuation value: 10dB; Wired link insertion loss: 3dB; Filter amplitude reduction factor: 2; The average power of the calibration source AD signal was calculated using the sum of squares and average method. ;See Figure 5 ; Because narrow pulse signals have a limited number of sampling points, directly using the sum of squares and averaging method results in significant errors. Therefore, envelope detection processing is performed on the original waveform. The original waveform of the narrow pulse signal is shown below. Figure 6 The waveform after envelope detection is shown below. Figure 7 .
[0026] The amplitude after envelope detection has been compensated for by the filter amplitude reduction factor. The average power of the electromagnetic narrow-pulse AD signal is then calculated. ; The power of the electromagnetic narrow pulse signal is =13.25-45+40-15+10+3=6.25dBm.
[0027] 1.2.4 Analysis of Power Calculation Accuracy There are two main types of errors affecting pulse amplitude measurement: systematic errors and random errors. Systematic errors can be compensated for through calibration, so we will consider random errors here. The main factors affecting measurement accuracy are as follows: (1) Amplitude error caused by thermal noise For pulse signals, the effect of thermal noise on amplitude error is as follows: ; In the formula, N represents the signal-to-noise ratio of a single pulse signal. e To effectively accumulate pulses, the signal-to-noise ratio is set to 20dB, and the number of accumulation cycles is 100.
[0028] but: It is 0.71%.
[0029] (2) Data quantization error ; In the formula, Measurement range: 12.5V (fixed attenuation 30dB). The quantization bit depth is set to 10 bits. Therefore, the quantization error of the output data is... The result is 0.0055%, indicating a small data quantization error.
[0030] (3) Calibration source output power calibration fitting error Linear fitting error of calibration source output power calibration data It is approximately 0.26%.
[0031] (4) Equipment measurement error The microwave power meter used is the German Rohde & Schwarz NRP-Z85 product. The equipment's measurement error... It is 1.75%.
[0032] (5) Cable insertion loss measurement error Cable insertion loss was measured using a vector network analyzer, and the measurement error was... It is 0.2%.
[0033] (6) Antenna pattern measurement error The standard horn antenna has been calibrated, and the antenna pattern measurement error has been determined. It is 3.58%.
[0034] Total measurement error for: .
[0035] The above description is merely an embodiment of the present invention and does not limit the scope of protection of the present invention. Any equivalent structural transformations made based on the content of the present invention specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the scope of protection of the present invention.
Claims
1. An electromagnetic narrow-pulse high-precision power measurement system, characterized in that, A standard horn antenna and a microwave power measurement device are set up, and the microwave power measurement device and the standard horn antenna are connected by an RF cable. The microwave power measurement equipment is equipped with a microwave module and a digital processing module; The microwave module is equipped with one calibration channel and one measurement channel. A thermistor is set on the microwave module as a temperature measuring point to monitor the temperature of the microwave module in real time. The measurement channel digitally attenuates the microwave radio frequency signal or calibration signal received by the standard horn antenna and mixes it to obtain the intermediate frequency signal; the calibration channel amplifies the signal from the calibration source to generate a stable output calibration signal. The digital processing module performs AD acquisition on the intermediate frequency signal output by the microwave module. On the one hand, it calculates the calibration signal power, and on the other hand, it performs envelope detection on the pulse waveform that exceeds the threshold, thereby calculating the pulse signal power.
2. The electromagnetic narrow-pulse high-precision power measurement system according to claim 1, characterized in that, The calibration channel consists of a frequency converter, an isolator, a filter, an attenuator, and a low-noise amplifier. It converts the crystal oscillator output signal from the calibration source and saturates the output signal through the low-noise amplifier, thereby generating a stable output calibration signal.
3. The electromagnetic narrow-pulse high-precision power measurement system according to claim 1 or 2, characterized in that, The digital processing module can also package and transmit pulse waveform data, and adjust the digitally controlled attenuator settings of the microwave module via a serial port.
4. The electromagnetic narrow-pulse high-precision power measurement system according to claim 1 or 2, characterized in that, The output power of the calibration signal output by the calibration channel is calibrated under full temperature conditions in the temperature chamber. The calibration test system is as follows: disconnect the connection between the calibration channel of the microwave module and the switch, and connect the calibration channel directly to the power meter. Place the calibration channel inside the temperature chamber and place the power meter outside the temperature chamber.
5. The measurement method of the electromagnetic narrow pulse high-precision power measurement system according to any one of claims 1-4, characterized in that, include: S1 calibration source full-temperature output power calibration: Open the calibration channel in the microwave module, and set the attenuation value to... dB, record the temperature of the microwave module. If the temperature is ℃, then the output power of the calibration source is dBm; S2 Wired Link Insertion Loss Measurement: The insertion loss of the wired link is measured as follows: dB; S3 Calibration Signal Digital Acquisition and Processing: The digital processing module performs AD acquisition and data processing on the calibration signal to obtain the digital power of the calibration signal. dB; S4 Electromagnetic Narrow Pulse Signal Acquisition and Processing: Open the measurement channel, attenuation value is... dB; S5 Electromagnetic Narrow Pulse Power Calculation: The digital processing module performs AD acquisition and data processing on the calibration signal from the measurement channel to obtain the digital power of the calibration signal. dB; The pulse microwave power value, dBm, is: .
6. The measurement method of the electromagnetic narrow pulse high-precision power measurement system according to claim 5, characterized in that, In step S5, the digital processing module performs down-conversion and low-pass filtering on the threshold-crossing pulse wave from the measurement channel. Assuming the pulse signal waveform of the calibration signal is... Perform a frequency conversion on it: j is the complex number symbol, f is the mixing frequency, and t is the time. After low-pass filtering, take the absolute value: ; in, This is the filter amplitude reduction factor. These are the filter coefficients. This is a convolution operation.
7. The measurement method of the electromagnetic narrow pulse high-precision power measurement system according to claim 5, characterized in that, The S1 calibration source full-temperature output power calibration specifically includes: disconnecting the calibration channel of the microwave module from the switch and directly connecting the calibration channel to the power meter. The calibration channel is placed inside the temperature chamber, and the power meter is placed outside the temperature chamber. The temperature chamber starts at a high temperature and is set in 5°C increments. The calibration source output power is collected under full-temperature conditions, with each increment lasting 2 hours to ensure stable calibration source output. The correlation between the calibration source output power and temperature is obtained by testing. Through linear fitting, the output power value of the calibration source at different temperatures can be obtained.