WO2023221423A1 - 基于微波的检测设备 - Google Patents

基于微波的检测设备 Download PDF

Info

Publication number
WO2023221423A1
WO2023221423A1 PCT/CN2022/131302 CN2022131302W WO2023221423A1 WO 2023221423 A1 WO2023221423 A1 WO 2023221423A1 CN 2022131302 W CN2022131302 W CN 2022131302W WO 2023221423 A1 WO2023221423 A1 WO 2023221423A1
Authority
WO
WIPO (PCT)
Prior art keywords
microwave
antenna
detection
module
amplitude
Prior art date
Application number
PCT/CN2022/131302
Other languages
English (en)
French (fr)
Inventor
谢勇
许用疆
姜春华
Original Assignee
上海兰宝传感科技股份有限公司
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 上海兰宝传感科技股份有限公司 filed Critical 上海兰宝传感科技股份有限公司
Publication of WO2023221423A1 publication Critical patent/WO2023221423A1/zh

Links

Images

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N22/00—Investigating or analysing materials by the use of microwaves or radio waves, i.e. electromagnetic waves with a wavelength of one millimetre or more

Definitions

  • the present invention belongs to the field of detection technology, and in particular, relates to a detection device based on microwave detection technology.
  • Microwave is a high-frequency electromagnetic wave with a wavelength of 1mm to 1m. As an electromagnetic signal, it will produce reflection, scattering and transmission when propagating at discontinuous interfaces.
  • the alternating electric field generated during the propagation process can produce orientation with the medium. Interactions such as polarization, atomic polarization, electronic polarization, and space charge polarization.
  • the amplitude, frequency, and phase of the microwave field will be affected by the material's dielectric constant, loss tangent, and the geometry and size of the material. Impact.
  • the dielectric properties of materials are jointly determined by factors such as material composition, organizational structure, and uniformity, and the dielectric properties of the medium will affect the microwave field.
  • the signal characteristics of electromagnetic waves will change to a certain extent when transmitting through non-metallic materials, and will not cause damage to the medium, so it is very suitable for non-destructive testing of non-metallic materials.
  • the internal condition of the inspected material can be studied and inferred.
  • the invention provides a microwave-based detection equipment, which has low cost, strong anti-interference ability and high accuracy.
  • the invention provides a microwave-based detection equipment, including a microwave module, an antenna module, a signal processing module, and a data processing module;
  • the antenna module includes a transmitting antenna and a receiving antenna, and the sample to be detected is arranged between the transmitting antenna and the receiving antenna;
  • the microwave module is connected to the antenna module and is used to provide excitation and detection of microwave signals.
  • the signal processing module is connected to the microwave module, and the signal processing module includes an amplitude detection circuit, an amplitude attenuation detection circuit, and a phase shift detection circuit;
  • the data processing module is connected to the signal processing module and is used to calculate and process the obtained microwave detection signal characteristic values to obtain detection parameter values of the sample to be detected.
  • the transmitting antenna and the receiving antenna in the antenna module are a pair of pyramid horn antennas.
  • the microwave module includes a dual-channel output microwave source and a dual-channel reference microwave source.
  • the dual-channel reference microwave source is used to eliminate fluctuation errors of microwave signals.
  • the microwave module further includes a power divider, a first mixer, a second mixer, a detector, and a photodiode (Positive Intrinsic Negative, PIN) switch;
  • One output end of the dual-channel output microwave source is connected in sequence to the power divider, the PIN switch, the antenna module, the detector, and the amplitude detection circuit of the signal processing module;
  • the other output end of the dual-channel output microwave source is connected in sequence to the first mixer, the phase shift detection circuit of the signal processing module, and the second mixer;
  • the two input terminals of the amplitude attenuation detection circuit of the signal processing module come from the power divider and the antenna module respectively;
  • the two output terminals of the dual-channel reference microwave source are respectively connected to the first mixer and the second mixer.
  • the antenna module further includes an antenna calibration station, and the transmitting antenna and the receiving antenna are placed on the antenna calibration station;
  • the antenna calibration platform includes a base, a track is provided on the base, and a runner is provided on the track.
  • the runner is used to support a receiving antenna moving bracket of the receiving antenna and a receiving antenna moving bracket that supports the transmitting antenna.
  • the transmitting antenna moving bracket moves on the track.
  • a capacitance scale is provided on the track of the antenna calibration platform for adjusting the moving distance of the receiving antenna moving bracket, the sample moving bracket, and the transmitting antenna moving bracket.
  • the base is provided with a scale digital display.
  • the data processing module is used for:
  • the true value of the physical quantity of the sample to be measured is w
  • the amplitude value of the received output signal is A
  • the phase shift is The amplitude attenuation value
  • a detection value w 1 is inverted from the amplitude value A, which is determined by the phase shift A detection value w 2 is inverted, and a detection value w 3 is inverted from the amplitude attenuation value V;
  • the detection value w 1 , detection value w 2 , and detection value w 3 are assigned weights k 1 , k 2 , and k 3 respectively, and the detection value of the sample to be tested is obtained after calculation.
  • the data processing module is used for data communication with a host computer, and the host computer is used for parameter setting of the detection device.
  • Figure 1 is a schematic diagram of the composition of a detection circuit provided by an embodiment
  • Figure 2 is a schematic structural diagram of an antenna calibration station provided in an embodiment
  • Figure 3 is a schematic structural diagram of a capacitive grid of an antenna calibration station provided in an embodiment
  • Figure 4 is a schematic diagram of the composition of a detection system provided by an embodiment
  • Figure 5 is a schematic diagram of a signal amplitude value-moisture content linear fitting provided by an embodiment
  • Figure 6 is a schematic diagram of a signal amplitude attenuation-moisture content linear fitting provided by an embodiment
  • Figure 7 is a schematic diagram of a signal phase shift-moisture content linear fitting provided by an embodiment.
  • radio frequency test equipment such as vector network analyzers and microwave power meters are used to measure microwave signal parameters.
  • These devices are usually relatively expensive, which restricts the development of microwave detection technology. As a result, this technology is often only suitable for measurement in laboratories and is difficult to apply in actual detection.
  • the signal when applying the microwave method for detection, the signal needs to be transmitted into free space to interact with the test piece before it can carry relevant information.
  • the energy of the signal itself is weak, and the energy loss is large after being transmitted and received, making it susceptible to environmental influences. It is affected by noise signals and temperature and humidity, and has poor anti-interference ability.
  • some detection circuits can only be applied to signal detection with low frequency, making it difficult to take advantage of microwave signals. Moreover, they can only detect a single signal parameter, which results in the inability to fully describe the changing characteristics of microwave signals and make it difficult to fully reflect them. The measured information results in poor detection results.
  • a microwave-based detection equipment or system that measures the three parameters of microwave signal amplitude value, amplitude attenuation value, and phase shift, as shown in Figure 1.
  • the purpose is to lay the foundation for reducing the cost of applying microwave technology, achieving accurate measurement of microwave signal parameters, and improving the detection range and anti-interference ability of the microwave method.
  • the system can process signal values online in real time, and display and store the data results into the host computer.
  • Microwave-based detection equipment includes microwave modules, antenna modules, signal processing modules, and data processing modules.
  • the microwave module mainly includes: two dual-channel microwave sources, power divider, mixer, detector, and photodiode (Positive Intrinsic Negative, PIN) switch.
  • the antenna module includes: a pair of pyramid horn antennas (transmitting antenna and receiving antenna), and an antenna calibration station.
  • the signal processing module includes: amplitude detection circuit, amplitude attenuation detection circuit, and phase shift detection circuit.
  • the data processing module is connected to the host computer.
  • the microwave module uses two independent dual-channel microwave sources to cooperate with each other, namely a dual-channel output microwave source and a dual-channel reference microwave source to achieve the measurement of three microwave signal characteristic values.
  • the main function of the dual-channel output microwave source is to simultaneously output two microwave signals of equal amplitude and phase, one of which is used as the input signal of the measurement system, and the other is used as the reference signal of the amplitude attenuation signal.
  • the main function of the dual-channel reference microwave source is to generate two in-phase microwave signals to provide reference signals for the phase detection circuit.
  • a stable reference is provided through a dual-channel reference microwave source. This method eliminates the impact of microwave signal power fluctuations and receiving antenna gain instability on measurement, as well as the impact of environmental noise and changes in experimental conditions on detection.
  • One output end of the dual-channel output microwave source is connected in sequence to the amplitude detection circuit of the power divider, PIN switch, antenna module, detector, and signal processing module.
  • the other output end of the dual-channel output microwave source is connected in sequence to the first mixer, the phase shift detection circuit of the signal processing module, and the second mixer.
  • the two input terminals of the amplitude attenuation detection circuit of the signal processing module come from the power divider and the antenna module respectively.
  • the two output terminals of the dual-channel reference microwave source are respectively connected to the first mixer and the second mixer.
  • the main function of the power divider is to divide one microwave signal into multiple channels, and there is a certain degree of isolation between different channels of signals so that they will not interfere with each other.
  • a two-power splitter can be used, that is, one microwave signal is equally divided into two channels.
  • the mixer is a dual-input and single-output microwave device. Its main function is to frequency-difference two microwave signals to obtain a low-frequency signal whose frequency is the difference between the two input frequencies.
  • Microwave antenna is a device that radiates microwave signals into free space and receives microwave signals from free space.
  • the test piece can be placed between the transmitting antenna and the receiving antenna.
  • the microwave signal is emitted from the transmitting antenna and can be carried after penetrating the tested piece.
  • the information of the device under test can be reflected after being received by the receiving antenna and processed.
  • the antenna mobile calibration table is a device that adjusts the coaxiality and spacing of the transmitting antenna and the receiving antenna.
  • the fixed part of the antenna is made of absorbing material, and there is a capacitance scale at the bottom.
  • the adjustment accuracy is 0.01mm, as shown in Figure 2 and Figure 3.
  • the antenna calibration station includes a base 20 with a track 19 provided on the base 20.
  • the receiving antenna moving bracket 14 supporting the receiving antenna 11 and the transmitting antenna moving bracket 16 supporting the transmitting antenna 10 move on the track 19 through the wheel 18.
  • the base 20 of the antenna calibration stage is provided with a scale 13 for adjusting the moving distance of the receiving antenna moving bracket 14, the sample moving bracket 15, and the transmitting antenna moving bracket 16.
  • the base 20 is also provided with a scale digital display 17 for observing the numerical value of the moving distance of the mobile bracket on the scale 13 .
  • the main function of the PIN switch is to control the microwave signal on and off and modulate the microwave signal, which can be controlled through 0, 1 digital signals.
  • the main function of the detector is to demodulate the modulated wave in the microwave signal and reflect the amplitude change of the signal.
  • the main function of the amplitude detection circuit is to measure the detected signal and detect the amplitude value of the microwave signal.
  • the microwave amplitude detected here is a relative value, that is, the amplitude of the microwave signal is reflected by the amplitude of the modulated wave.
  • the main function of the amplitude attenuation circuit is to compare the amplitude changes of the amplitude reference signal and the detection signal, and detect the amplitude attenuation value of the microwave signal.
  • the amplitude attenuation here is an absolute value, that is, the amplitude of the microwave detection signal and the amplitude of the original microwave signal are logarithmically The value after the operation.
  • the main function of the phase shift detection circuit is to compare the phase changes of the reference signal and the detection signal.
  • the phase shift here is an absolute value, which is obtained by measuring the phase change of the low-frequency signal after the phase reference signal is mixed with the detection signal and the original signal respectively. .
  • the main function of the data processing module is to comprehensively use the three parameters of amplitude value, amplitude attenuation value, and phase shift value to represent the same information to be measured, and solve the problem of low detection accuracy of a single parameter.
  • the true value of the physical quantity to be measured is w
  • the system will simultaneously output the amplitude value A and the phase shift.
  • Amplitude attenuation value V The amplitude value A can be inverted into a detection value w 1 , and the phase shift A detection value w 2 can be inverted, and the amplitude attenuation value V can be inverted to a detection value w 3 .
  • This module gives each detection value a certain weight k 1 , k 2 , k 3 according to the least square method. After calculation, it is A comprehensive detection value can be output.
  • Equation (1) The empirical formula for determining the moisture content W of wood is written as a linear equation, as shown in Equation (1).
  • the corresponding true values of moisture content are W 1 , W 2 , W 3 ...W m respectively, and W i is The true moisture content of the i-th wood, that is, the true value of the moisture content, is the moisture content determined by the drying method.
  • a i is the amplitude measured by the i-th wood, The phase measured for the i-th wood.
  • the coefficients of the empirical formula are determined by minimizing the sum of squared errors.
  • the expression for calculating the sum of squares of moisture content errors can be expressed as equation (3).
  • the partial derivative of each coefficient of the target expression can be equal to zero, that is, the system of equations shown in equation (4) should be satisfied.
  • Equation (5) can be regarded as a system of linear equations about the unknown coefficients k 1 and k 2 of the empirical formula. By solving this linear equation, k 1 and k 2 can be obtained.
  • the main functions of the host computer software are to display the three detection parameters, convert the voltage value into secondary comprehensive calculation and storage of moisture content, and set the dual-channel output microwave source frequency and modulated wave signal frequency.
  • This equipment uses modulation and frequency reduction methods to convert difficult-to-process high-frequency signals into easy-to-process low-frequency signals. It converts the phase difference of high-frequency signals from 1.7GHz to 2.6GHz into a low-frequency signal phase difference of 100KHz. The amplitude of the high-frequency signal of ⁇ 2.6GHz is converted into the amplitude of the low-frequency signal of 1KHz. The frequency of the detection signal is lowered, and the processing is more convenient, which greatly reduces the cost of using the microwave method. Compared with the vector network analyzer ((industry standard microwave signal analysis equipment, model: Keysight M9374A)), it has achieved greater accuracy in microwave signal measurement. Replacement, cost reduced by 80%.
  • this equipment adopts the modulation method.
  • the frequency and amplitude of the modulated wave are easy to control accurately.
  • the amplitude of the modulated wave changes synchronously with the carrier wave (microwave signal). This ensures that the detected signal amplitude can accurately reflect the amplitude of the microwave signal.
  • this equipment uses a combination of two dual-channel microwave sources, and sets a reference signal for amplitude attenuation and phase shift. When the detection environment changes, the test signal and the reference signal will change synchronously. This Eliminates the impact of ambient temperature and humidity conditions on the system.
  • the antenna mobile station is used to fix and adjust the relative position of the antenna, which avoids the impact on microwave signals caused by uncoordinated antenna positions, making the equipment not restricted by installation and use conditions, and improving the practicality of the equipment.
  • the synchronous measurement of amplitude, amplitude attenuation and phase shift is realized.
  • the system can output these three parameter values at the same time. This allows three detection values to be output when detecting the same object, and then the three detection values can be processed through the data processing module.
  • the signal values are assigned weights through the least square method and characterize the same physical quantity to be measured, which can reduce the interference of external noise signals, remove accidental errors, and make up for the problem of low detection accuracy of a single parameter. It can be compared with microwave signal characteristics (such as High-precision inversion of physical quantities related to moisture content).
  • microwave power control devices including power amplifiers and program-controlled attenuators, can be added according to actual usage scenarios.
  • One output end of the dual-channel output microwave source is connected to the amplitude attenuation detection circuit, and the other output end is connected in sequence to the power divider 1, the mixer 4, the band-pass filter 6, and the phase shift detection circuit.
  • the other output end of the power divider 1 is connected in sequence to the microwave signal power/on-off control module (PIN), transmitting antenna, receiving antenna, power amplifier, and power divider 2.
  • PIN microwave signal power/on-off control module
  • One output end of the power divider 2 is connected to the amplitude attenuation detection circuit through a filter, and the other output end of the power divider 2 is connected to the power divider 3, the detector, and the amplitude detection circuit in sequence.
  • An output end of the power divider 3 is connected to the mixer 5, the bandpass filter 7, and the phase shift detection circuit in sequence.
  • One output end of the dual-channel reference signal source is connected to mixer 4, and the other output end is connected to mixer 5.
  • the circuit detection signal flow is as follows:
  • the dual-channel output microwave source has two equal-amplitude signals a 1 (t) and a 2 (t), and a 2 (t) is connected to the amplitude attenuation detection circuit as the reference signal for amplitude attenuation detection.
  • a 1 (t) is connected to the power divider 1, and the signal is divided into two signals b 1 (t) and b 2 (t) by the power divider 1.
  • One channel of the power divider 1 is connected to the mixer 4, b 1 (t) is mixed with the output signal d 1 (t) of the dual-channel reference signal source to become m 1 (t), and m 1 (t) is filtered Connected to the phase shift detection circuit as the reference signal for phase shift detection.
  • Another signal b 2 (t) is connected to the microwave signal power/on-off control module as an input signal.
  • the microwave signal power/on-off control module includes: power amplifier, program-controlled attenuator, PIN switch, isolator. After the signal is power adjusted and reflected and isolated, it is used as a microwave detection signal through the microwave transmitting antenna and receiving antenna, and then is power amplified to c (t).
  • the microwave detection signal c(t) is connected to the power divider 2 and is divided into two signals: c 1 (t) and c 2 (t). Among them, c 1 (t) is filtered and connected to the amplitude attenuation detection circuit as the amplitude attenuation The detection signal is compared with the amplitude of a 2 (t) in the amplitude attenuation detection circuit, and the signal amplitude attenuation A can be detected. The other c 2 (t) is connected to the power divider 3.
  • c 2 (t) is divided into two signals r 1 (t) and r 2 (t) after passing through the power divider 3. After r 1 (t) is detected, it is connected to the amplitude detection circuit to output the relative amplitude value of the microwave signal. V. Another signal r 2 (t) is connected to the mixer 5 and mixed with the d 2 (t) output by the reference signal source to m 2 (t). The signal m 2 (t) is band-pass filtered and used as a phase-shifted The detection signal is connected to the phase shift detection circuit, and is calculated with m 1 (t) in the circuit to output the phase shift ⁇ of the microwave signal.
  • Figure 5 is the amplitude value-moisture content linear fitting curve
  • Figure 6 is the amplitude attenuation-moisture content linear fitting curve
  • Figure 7 is the phase shift-moisture content linear fitting curve.
  • linear fitting of amplitude and moisture content linear fitting of phase shift and moisture content, linear fitting of amplitude attenuation and moisture content
  • x is the signal value
  • f(x) is the calculated moisture content
  • the linearity is the data Fitting ability is expressed as the ability of the detection signal to explain the moisture content.
  • the solution provided by the present invention has a high detection effect and is also higher than the detection accuracy of the vector network analyzer for detecting moisture content.

Landscapes

  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Health & Medical Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Chemical & Material Sciences (AREA)
  • Analytical Chemistry (AREA)
  • Biochemistry (AREA)
  • General Health & Medical Sciences (AREA)
  • General Physics & Mathematics (AREA)
  • Immunology (AREA)
  • Pathology (AREA)
  • Geophysics And Detection Of Objects (AREA)
  • Measurement Of Resistance Or Impedance (AREA)

Abstract

一种基于微波的检测设备，包括微波模块、天线模块、信号处理模块以及数据处理模块。天线模块包括发射天线（10）与接收天线（11），待检样本（12）被设置在发射天线（10）和接收天线（11）之间；微波模块与天线模块连接，用于提供微波信号的激励和检波；信号处理模块与微波模块连接，信号处理模块包括幅度检测电路、幅度衰减检测电路以及相移检测电路；数据处理模块与信号处理模块连接，用于对获得的微波检测信号特征值进行计算处理，获得待检样本（12）的检测参数值。

Description

基于微波的检测设备
本申请要求在2022年05月20日提交中国专利局、申请号为202210550202.8的中国专利申请的优先权，该申请的全部内容通过引用结合在本申请中。
技术领域
本发明属于检测技术领域，特别例如涉及一种基于微波检测技术的检测设备。
背景技术
微波是波长为1mm～1m的高频电磁波，作为一种电磁信号，在不连续界面处传播时会产生反射、散射、透射，而在传播过程中产生的交变电场，又能与介质产生取向极化、原子极化、电子极化、空间电荷极化等互作用，此时微波场的振幅、频率和相位等参数会受到材料介电常数、损耗角正切以及材料的几何形状、尺寸等参数的影响。材料的介电性质是由物质组成、组织结构、均匀性等因素共同决定，而介质的介电特性会对微波场产生影响。因此，电磁波在透射过非金属材料时信号特征会发生一定的变化，且对介质不会产生破坏，故非常适用于对非金属材料进行无损检测。根据微波场的参量变化，可以研究推断被检材料的内部状况。
发明内容
本发明提供一种基于微波的检测设备，该检测设备成本低，抗干扰能力强，精度高。
本发明提供一种基于微波的检测设备，包括微波模块、天线模块、信号处理模块、以及数据处理模块；
所述天线模块包括发射天线与接收天线，待检样本被设置在发射天线和接收天线之间；
所述微波模块与所述天线模块连接，用于提供微波信号的激励和检波
所述信号处理模块与所述微波模块连接，所述信号处理模块包括幅度检测电路、幅度衰减检测电路、以及相移检测电路；
数据处理模块与所述信号处理模块连接，用于对获得的微波检测信号特征值进行计算处理，获得所述待检样本的检测参数值。
一实现方式中，所述天线模块中的发射天线与接收天线，是一对角锥喇叭天线。
一实现方式中，所述微波模块中包括双通道输出微波源和双通道参考微波源，所述双通道参考微波源用于消除微波信号的波动误差。
一实现方式中，所述微波模块还包括功率分配器、第一混频器、第二混频器、检波器、以及光电二极管(Positive Intrinsic Negative，PIN)开关；
所述双通道输出微波源的一个输出端，依次连接所述功率分配器、所述PIN开关、所述天线模块、所述检波器、以及所述信号处理模块的幅度检测电路；
所述双通道输出微波源的另一个输出端，依次连接所述第一混频器、所述信号处理模块的相移检测电路、以及所述第二混频器；
所述信号处理模块的幅度衰减检测电路的2个输入端分别来自功率分配器和天线模块；
所述双通道参考微波源的2个输出端分别接入第一混频器和第二混频器。
一实现方式中，所述天线模块还包括天线校准台，所述发射天线和所述接收天线被置于所述天线校准台；
所述天线校准台包括底座，在所述底座上设有轨道，所述轨道上设置有转轮，所述转轮用于支撑所述接收天线的接收天线移动托架以及支撑所述发射天线的发射天线移动托架在所述轨道上移动。
一实现方式中，所述天线校准台的轨道上设有容栅尺，用于调整所述接收天线移动托架、所述样本移动托架、以及所述发射天线移动托架的移动距离。
一实现方式中，所述底座上设有容栅尺数字显示屏。
一实现方式中，所述数据处理模块用于：
设所述待测样本的物理量真值为w，接收到的输出信号的幅度值为A、相移为
Figure PCTCN2022131302-appb-000001
幅度衰减值为V；
由幅度值A反演出一个检测值w 1，由相移
Figure PCTCN2022131302-appb-000002
反演出一个检测值w 2，由幅度衰减值V反演出一个检测值w 3；
分别赋予检测值w 1、检测值w 2、检测值w 3以权重k 1、k 2、k 3，经过运算后获得待测样本检测值。
一实现方式中，所述数据处理模块用于与上位机进行数据通信，所述上位机用于对所述检测设备进行参数设定。
附图说明
图1是一实施例提供的一种检测电路的组成示意图；
图2是一实施例提供的一种天线校准台的结构示意图；
图3是一实施例提供的一种天线校准台的容栅的结构示意图；
图4是一实施例提供的一种检测系统的组成示意图；
图5是一实施例提供的一种信号幅度值-含水率线性拟合的示意图；
图6是一实施例提供的一种信号幅度衰减-含水率线性拟合的示意图；
图7是一实施例提供的一种信号相移-含水率线性拟合的示意图。
其中，
10、发射天线；11、接收天线；12、待检样本；13、容栅尺；14、接收天线移动托架；15、样本移动托架；16、发射天线移动托架；17、容栅尺显示屏；18、转轮；19、轨道；20、底座。
具体实施方式
应用微波法对待检材料进行检测时，由于微波信号的频率较高，微波信号参数的测量都采用矢量网络分析仪、微波功率计等射频测试设备。这些设备通常价格较为昂贵，制约了微波检测技术的发展，导致了这项技术往往只适合在实验室中测量，难以应用于实际检测中。
此外，应用微波法检测时，需要将信号发射到自由空间中与被测试件相互作用后才能携带相关信息，而信号本身的能量较弱，再经发射和接收后能量损失较大，易受到环境噪声信号与温湿度的影响，抗干扰能力差。
同时，部分的检测电路只能适用于频率不是很高的信号检测中，难以发挥出微波信号的优势，且只能检测单一信号参数而导致对微波信号的变化特征不能完全描述，难以全面反映出被测信息，导致检测效果差。
针对微波测量法存在的问题，提供一种测量微波信号幅度值、幅度衰减值、相移三参数的基于微波的检测设备或系统，如图1所示。目的是为降低应用微波技术成本，实现微波信号参数的精准测量，提高微波法的检测范围以及抗干扰能力奠定基础。该系统可在线实时处理信号值，并将数据结果显示与存储到上位机中。
基于微波的检测设备包括微波模块、天线模块、信号处理模块、以及数据处理模块。
微波模块主要包括：两只双通道微波源、功率分配器、混频器、检波器、以及光电二极管(Positive Intrinsic Negative，PIN)开关。
天线模块包括：一对角锥喇叭天线(发射天线与接收天线)、以及天线校准台。
信号处理模块包括：幅度检测电路、幅度衰减检测电路、相移检测电路。
数据处理模块与上位机连接。
微波模块采用两个独立的双通道微波源相互配合，即双通道输出微波源和双通道参考微波源，实现三种微波信号特征值的测量。
双通道输出微波源的主要功能是同时输出两路等幅同相的微波信号，其中一路作为测量系统的输入信号，另一路作为幅度衰减信号的参考信号。而双通道参考微波源的主要功能是产生两路同相微波信号，为相位检测电路提供参考信号。通过双通道参考微波源，提供稳定的参考，这种方法消除了微波信号功率波动和接收天线增益不稳为测量带来的影响，以及环境噪声和实验条件变化对检测的影响。
所述双通道输出微波源的一个输出端，依次连接功率分配器、PIN开关、天线模块、检波器、信号处理模块的幅度检测电路。所述双通道输出微波源的另一个输出端，依次连接第一混频器、信号处理模块的相移检测电路、第二混频器。信号处理模块的幅度衰减检测电路的2个输入端分别来自功率分配器和天线模块。所述双通道参考微波源的2个输出端分别接入第一混频器和第二混频器。
功率分配器的主要功能是将一路微波信号等分为多路，且不同路信号之间存在一定的隔离度，不会相互产生干扰。在本实施例中，可以采用二功分分配器，即将一路微波信号等分为两路。
混频器是一种双输入单输出的微波器件，其主要功能是将两路微波信号进行差频，获得一路频率为两个输入频率之差的低频信号。
微波天线是辐射微波信号到自由空间中且从自由空间中接收微波信号的器件，发射天线与接收天线之间可放置被测试件，微波信号从发射天线发出，穿透被测试件后即可携带被测试件的信息，经接收天线接收后进行处理可反映出该信息。
天线移动校准台是调整发射天线与接收天线的同轴度、间距的装置，天线固定部分采用吸波材料，底部设有容栅尺，调节精度为0.01mm，如图2以及图3所示。
天线校准台包括底座20，在底座20上设有轨道19，通过转轮18，支撑接收天线11的接收天线移动托架14以及支撑发射天线10的发射天线移动托架16在轨道19上移动。所述天线校准台的底座20上设有容栅尺13，用于调整所述接收天线移动托架14、样本移动托架15、以及发射天线移动托架16的移动距离。底座20上还设有容栅尺数字显示屏17，用于观察移动托架在容栅尺13上的移动距离的数值。
PIN开关的主要功能是控制微波信号通断并对微波信号进行调制，可通过0，1数字信号进行控制。
检波器的主要功能是将微波信号中的调制波解调，反映出信号的幅度变化。
幅度检测电路的主要功能是对检波后的信号进行测量，检测出微波信号的幅度值，这里检测的微波幅度为相对值，即通过调制波幅度的反映出微波信号的幅度。
幅度衰减电路的主要功能是对比幅度参考信号与检测信号的幅度变化，检测微波信号的幅度衰减值，这里的幅度衰减为绝对值，即通过微波检测信号的幅度与微波原始信号的幅度进行对数运算后的值。
相移检测电路的主要功能是对比参考信号与检测信号的相位变化，这里的相移为绝对值，即通过测量相位参考信号与检测信号和原始信号分别混频后的低频信号的相位变化得出。
数据处理模块的主要功能是将幅度值、幅度衰减值、相移值三种参数综合用于表征同一待测信息，解决单一参数检测精度不高的问题。
当发射天线和接收天线之间放置待测样本试件时，待测物理量真值为w，系统会同时输出幅度值A、相位相移
Figure PCTCN2022131302-appb-000003
幅度衰减值V。幅度值A可反演出一个检测值w 1，相位相移
Figure PCTCN2022131302-appb-000004
可反演出一个检测值w 2，幅度衰减值V可反演出一个检测值w 3，该模块根据最小二乘法赋予每一检测值一定的权重k 1、k 2、k 3，再经过运算后即可输出一个综合检测值。
以下给出幅度和相位相移两个参数的综合计算方法，而幅度衰减的综合计算方法因为类似，不再另外举例。
通过试验和仿真研究发现，传输系数S 21的幅值A与木材含水率W呈线性关系，相位
Figure PCTCN2022131302-appb-000005
与木材含水率W也呈线性关系。由幅值A和相位
Figure PCTCN2022131302-appb-000006
确定木材含水率W的经验公式为线性方程写成如式(1)所示。
Figure PCTCN2022131302-appb-000007
将式(1)写为向量的形式，如式(2)所示。
Figure PCTCN2022131302-appb-000008
木材的种类、测量频率不变，当同一木材有m个不同的含水率的值时，对应的含水率的真值分别为W 1、W 2、W 3...W m，记W i为第i个木材的真实含水率，即含水率真值，通过烘干法确定的含水率。A i为第i个木材测量所得幅值，
Figure PCTCN2022131302-appb-000009
为第i个木材测量所得相位。采用令误差平方和最小的方式来确定经验公式的系数。计算含水率误差平方和的表达式可表示为式(3)。
Figure PCTCN2022131302-appb-000010
为了使误差平和最小，可令目标表达式对每个系数的偏导等于零，即应满足式(4)所示的方程组。
Figure PCTCN2022131302-appb-000011
将式(3)带入式(4)，可得式(5)。
Figure PCTCN2022131302-appb-000012
式(5)可以视为关于经验公式未知系数k 1和k 2的线性方程组，求解该线性方程即可求出k 1、k 2。
上位机软件的主要功能是对三种检测参数进行显示、将电压值转换成含水率的二次综合计算、存储，并对双通道输出微波源频率、调制波信号频率进行设定。
本实施例的效果包括：
1、实现了微波信号幅度、幅度衰减、相移的低成本测量。本设备采用调制和降频的方法，将难处理的高频信号转化为易处理的低频信号，将1.7GHz～2.6GHz的高频信号的相位差转换为100KHz的低频信号相位差，将1.7GHz～2.6GHz的高频信号幅度转换为1KHz的低频信号的幅度。检测信号的频率降低，处理更为方便，极大地降低了使用微波法的成本，相比于矢量网络分析仪((行业标准微波信号分析设备，型号：Keysight M9374A))在微波信号 测量上实现了替代，成本降低了80％。
2、实现了微波信号幅度、幅度衰减、相移的精准测量。对于幅度值，本设备采用调制的方法，调制波的频率和幅度容易精准控制，调制波幅度随载波(微波信号)同步变化，这保证了检波出的信号幅度可以准确反映微波信号的幅度。对于幅度衰减和相移，在本设备中采用了两个双通道微波源的组合，对幅度衰减、相移设置了参考基准信号，当检测环境改变时，测试信号和参考信号会同步变化，这消除了环境温湿度条件对系统的影响。
3、采用天线移动台固定和调节天线的相对位置，避免了天线位置不协调导致对微波信号的影响，使得本设备不受安装和使用条件的限制，提升了本设备的实用性。
4、实现了幅度、幅度衰减、相移的同步测量，系统可同时输出这三个参数值，这使得在对同一对象进行检测时，可输出三个检测值，再通过数据处理模块可将三种信号值通过最小二乘法进行权重赋值并对同一待测物理量进行表征，可以减小外界噪声信号的干扰，去除偶然误差，弥补单一参数检测精度不高的问题，可实现与微波信号特征(如含水率)相关物理量的高精度反演。
下面结合本发明的检测设备在云杉含水率检测中的应用，说明其操作流程和实际检测效果。参照图4，在使用本发明的设备时，检测电路中除上述的器件外，可根据实际使用场景增加微波功率控制器件，包括功率放大器和程控衰减器。
双通道输出微波源一个输出端连接幅度衰减检测电路，另一个输出端依次连接功率分配器1、混频器4、带通滤波器6、相移检测电路。功率分配器1的另一个输出端依次连接微波信号功率/通断控制模块(PIN)、发射天线、接收天线、功率放大器、功率分配器2。功率分配器2的一个输出端经过滤波器连接幅度衰减检测电路，功率分配器2的另一个输出端依次连接功率分配器3、检波器、幅度检测电路。功率分配器3的一个输出端依次连接混频器5、带通滤波器7、相移检测电路。双通道参考信号源的一个输出端连接混频器4，另一个输出端连接混频器5。
电路检测信号流程如下：
双通道输出微波源两路等幅的信号a 1(t)和a 2(t)，a 2(t)连接幅度衰减检测电路，作为幅度衰减检测的基准信号。a 1(t)连接功率分配器1，该信号被功率分配器1分为b 1(t)和b 2(t)两路信号。
功率分配器1的一路连接至混频器4，b 1(t)与双通道参考信号源的一路输出信号d 1(t)混频为m 1(t)，m 1(t)经滤波后连接至相移检测电路，作为相移检测的基准 信号。另一路信号b 2(t)作为输入信号连接至微波信号功率/通断控制模块。
微波信号功率/通断控制模块包括：功率放大器、程控衰减器、PIN开关、隔离器，将信号进行功率调整与反射隔离后经微波发射天线与接收天线作为微波检测信号，再经功率放大为c(t)。
微波检测信号c(t)连接至功率分配器2被分为c 1(t)和c 2(t)两路信号，其中c 1(t)经滤波后连接至幅度衰减检测电路，作为幅度衰减的检测信号，在幅度衰减检测电路中与a 2(t)的幅度进行对比，即可检测出信号幅度衰减A。另一路c 2(t)连接至功率分配器3。
c 2(t)经功率分配器3后被分为r 1(t)和r 2(t)两路信号，r 1(t)经过检波后连接至幅度检测电路，输出微波信号的幅度相对值V。另一路信号r 2(t)连接至混频器5，与参考信号源输出的d 2(t)混频为m 2(t)，信号m 2(t)经过带通滤波后作为相移的检测信号连接至相移检测电路，在电路中与m 1(t)计算，即可输出微波信号的相移Φ。
幅度检测信号、幅度衰减检测信号和相移检测信号与含水率的关系如图5、6、以及7所示。图5是幅度值-含水率线性拟合曲线，图6是幅度衰减-含水率线性拟合曲线，图7是相移-含水率线性拟合曲线。
对其进行线性拟合，线性拟合函数f(x)＝0.348x-2.868。线性度R-square＝0.993，幅度衰减对其进行线性拟合f(x)＝7.991x-29，线性度R-square＝0.991，相位的f(x)＝-0.948x-13.6，R-square＝0.985。
即，幅度和含水率线性拟合、相位相移和含水率线性拟合、幅度衰减和含水率进行线性拟合，x为信号值，f(x)为计算出的含水率，线性度为数据拟合能力，表示为检测信号对含水率的解释能力。
通过以上三个关系式，可通过最小二乘的方法求解出k 1＝0.423，k 2＝0.356，k 3＝0.221，综合计算反演的含水率结果如表1所示。
表1综合检测结果
真实值 计算值 绝对误差
33.20％ 32.66％ 0.46％
25.60％ 25.84％ 0.24％
14.80％ 14.57％ 0.23％
8.20％ 7.82％ 0.38％
因此，从表1可以看出，本发明给出的方案检测效果高，也比矢量网络分 析仪检测含水率的检测精度要高
以上所述，仅为本发明的具体实施方式，但本发明的保护范围并不局限于此，任何熟悉本技术领域的技术人员在本发明揭露的技术范围内，可轻易想到各种等效的修改或替换，这些修改或替换都应涵盖在本发明的保护范围之内。因此，本发明的保护范围应以权利要求的保护范围为准。

Claims (9)

  1. 一种基于微波的检测设备，包括微波模块、天线模块、信号处理模块、以及数据处理模块；
    所述天线模块包括发射天线与接收天线，待检样本被设置在所述发射天线和所述接收天线之间；
    所述微波模块，与所述天线模块连接，用于提供微波信号的激励和检波；
    所述信号处理模块，与所述微波模块连接，所述信号处理模块包括幅度检测电路、幅度衰减检测电路、以及相移检测电路；
    所述数据处理模块，与所述信号处理模块连接，用于对获得的微波检测信号特征值进行计算处理，获得所述待检样本的检测参数值。
  2. 根据权利要求1所述的检测设备，其中，所述天线模块中的发射天线与接收天线，是一对角锥喇叭天线。
  3. 根据权利要求1所述的检测设备，其中，所述微波模块中包括双通道输出微波源和双通道参考微波源，所述双通道参考微波源用于消除微波信号的波动误差。
  4. 根据权利要求3所述的检测设备，其中，所述微波模块还包括功率分配器、第一混频器、第二混频器、检波器、以及光电二极管PIN开关；
    所述双通道输出微波源的一个输出端，依次连接所述功率分配器、所述PIN开关、所述天线模块、所述检波器、以及所述信号处理模块的幅度检测电路；
    所述双通道输出微波源的另一个输出端，依次连接所述第一混频器、所述信号处理模块的相移检测电路、以及所述第二混频器；
    所述信号处理模块的幅度衰减检测电路的2个输入端分别来自功率分配器和天线模块；
    所述双通道参考微波源的2个输出端分别接入第一混频器和第二混频器。
  5. 根据权利要求2所述的检测设备，其中，所述天线模块还包括天线校准台，所述发射天线和所述接收天线被置于所述天线校准台；
    所述天线校准台包括底座，在所述底座上设有轨道，所述轨道上设置有转轮，所述转轮用于支撑所述接收天线的接收天线移动托架以及支撑所述发射天线的发射天线移动托架在所述轨道上移动。
  6. 根据权利要求5所述的检测设备，其中，所述天线校准台的轨道上设有容栅尺，用于调整所述接收天线移动托架、所述样本移动托架、以及所述发射天线移动托架的移动距离。
  7. 根据权利要求6所述的检测设备，其中，所述底座上设有容栅尺数字显示屏。
  8. 根据权利要求1所述的检测设备，其中，所述数据处理模块用于：
    设所述待测样本的物理量真值为w，接收到的输出信号的幅度值为A、相移为
    Figure PCTCN2022131302-appb-100001
    幅度衰减值为V；
    由幅度值A反演出一个检测值w 1，由相移
    Figure PCTCN2022131302-appb-100002
    反演出一个检测值w 2，由幅度衰减值V反演出一个检测值w 3；
    分别赋予检测值w 1、检测值w 2、检测值w 3以权重k 1、k 2、k 3，经过运算后获得待测样本检测值。
  9. 根据权利要求8所述的检测设备，其中，所述数据处理模块用于与上位机进行数据通信，所述上位机用于对所述检测设备进行参数设定。
PCT/CN2022/131302 2022-05-20 2022-11-11 基于微波的检测设备 WO2023221423A1 (zh)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN202210550202.8A CN114965511A (zh) 2022-05-20 2022-05-20 基于微波的检测设备及电路
CN202210550202.8 2022-05-20

Publications (1)

Publication Number Publication Date
WO2023221423A1 true WO2023221423A1 (zh) 2023-11-23

Family

ID=82984750

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2022/131302 WO2023221423A1 (zh) 2022-05-20 2022-11-11 基于微波的检测设备

Country Status (2)

Country Link
CN (1) CN114965511A (zh)
WO (1) WO2023221423A1 (zh)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114965511A (zh) * 2022-05-20 2022-08-30 上海兰宝传感科技股份有限公司 基于微波的检测设备及电路

Citations (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4727311A (en) * 1986-03-06 1988-02-23 Walker Charles W E Microwave moisture measurement using two microwave signals of different frequency and phase shift determination
US5939888A (en) * 1997-08-26 1999-08-17 New Holland North America, Inc. Digital method and apparatus for monitoring moisture content
CN101566587A (zh) * 2009-05-25 2009-10-28 清华大学 双源双探头正交式微波测量含水率装置及测量方法
CN101907579A (zh) * 2009-06-05 2010-12-08 西安阿尔特科技实业发展有限责任公司 一种微波法棉花回潮率在线测量系统
CN101907578A (zh) * 2009-06-05 2010-12-08 西安阿尔特科技实业发展有限责任公司 一种微波法棉花回潮率在线测量系统的实现方法
CN103399022A (zh) * 2013-07-25 2013-11-20 湖南合立拓普科技有限公司 一种烟包在线微波水分检测方法及系统
CN105424727A (zh) * 2014-09-12 2016-03-23 航天信息股份有限公司 利用微波在线检验粮食水分含量是否超标的方法和装置
CN105572150A (zh) * 2014-10-16 2016-05-11 航天信息股份有限公司 基于扩频的双通道粮食水分测量方法和装置
CN109632832A (zh) * 2019-01-23 2019-04-16 浙江大学 一种基于扫频微波穿透法的谷物含水率测量装置
US20200378903A1 (en) * 2018-12-26 2020-12-03 Jiangsu Maihe Internet Of Things Technology Co., Ltd Detection system and detection method for water content and conductivity
CN114965511A (zh) * 2022-05-20 2022-08-30 上海兰宝传感科技股份有限公司 基于微波的检测设备及电路

Patent Citations (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4727311A (en) * 1986-03-06 1988-02-23 Walker Charles W E Microwave moisture measurement using two microwave signals of different frequency and phase shift determination
US5939888A (en) * 1997-08-26 1999-08-17 New Holland North America, Inc. Digital method and apparatus for monitoring moisture content
CN101566587A (zh) * 2009-05-25 2009-10-28 清华大学 双源双探头正交式微波测量含水率装置及测量方法
CN101907579A (zh) * 2009-06-05 2010-12-08 西安阿尔特科技实业发展有限责任公司 一种微波法棉花回潮率在线测量系统
CN101907578A (zh) * 2009-06-05 2010-12-08 西安阿尔特科技实业发展有限责任公司 一种微波法棉花回潮率在线测量系统的实现方法
CN103399022A (zh) * 2013-07-25 2013-11-20 湖南合立拓普科技有限公司 一种烟包在线微波水分检测方法及系统
CN105424727A (zh) * 2014-09-12 2016-03-23 航天信息股份有限公司 利用微波在线检验粮食水分含量是否超标的方法和装置
CN105572150A (zh) * 2014-10-16 2016-05-11 航天信息股份有限公司 基于扩频的双通道粮食水分测量方法和装置
US20200378903A1 (en) * 2018-12-26 2020-12-03 Jiangsu Maihe Internet Of Things Technology Co., Ltd Detection system and detection method for water content and conductivity
CN109632832A (zh) * 2019-01-23 2019-04-16 浙江大学 一种基于扫频微波穿透法的谷物含水率测量装置
CN114965511A (zh) * 2022-05-20 2022-08-30 上海兰宝传感科技股份有限公司 基于微波的检测设备及电路

Also Published As

Publication number Publication date
CN114965511A (zh) 2022-08-30

Similar Documents

Publication Publication Date Title
CN105929222B (zh) 适用于高稳射频信号功率稳定度的测试系统及方法
CN109669075B (zh) 基于开口矩形波导的介质复介电常数无损反射测量方法
GB2382662B (en) High frequency circuit analyzer
WO2023221423A1 (zh) 基于微波的检测设备
CN103647612B (zh) 一种用于波导系统的衰减测量装置
CN104270208B (zh) 一种远端射频单元rru驻波比检测的方法及装置
CN110601773B (zh) 辐射杂散测试方法及装置、测试系统
CN102752061A (zh) 毫米波衰减测量系统锁相放大器参考信号产生装置及方法
CN102608434B (zh) 一种毫米波黑体散射系数的测量方法
US11303366B2 (en) Passive harmonic test system and method
CN112558001B (zh) 一种脉冲高功率现场校准装置和方法
CN113125857A (zh) 一种基于开路同轴线的吸波材料介电参数测量与反演方法
CN109580661B (zh) 一种自由空间材料复反射系数测试方法
CN110441723B (zh) 一种太赫兹探针瞬态响应校准方法和装置
Wu Accurate measurement of millimeter-wave attenuation from 75 GHz to 110 GHz using a dual-channel heterodyne receiver
CN110474695A (zh) 一种适用于微波辐射计通道间能量互扰的检验和优化方法
CN103701538A (zh) 一种用于波导系统的衰减测量方法
Roussy et al. Six-port waveguide used for simultaneously measuring permittivity and permeability of solid materials in the microwave region
Coşkun et al. Search for suitability of relatively narrow test sites for antenna calibration according to ANSI C63. 5-2006 standard site method–A case study in Istanbul-Turkey
Bittera et al. Alternative Approach Leading to Reduction in Measurement Instrument Uncertainty of EMI Measurement
Bittera et al. Modified uncertainty estimation of antenna factor measurement by standard site method
US11237197B1 (en) Method and systems for making improved quasi-linear/nonlinear measurements on integrated antenna arrays and elements
CN115639514A (zh) 微波倍频测试系统的非线性误差的开环测量方法
Chaochan et al. Evaluation of Measurement Uncertainty of Shielding Effectiveness for Electromagnetic Shielding Films
Li et al. Generating field strength measurement standard in GTEM cell by using transfer standard

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 22942444

Country of ref document: EP

Kind code of ref document: A1