CN204882407U - A microwave radar host computer for surveying water instrument - Google Patents

Abstract

The utility model discloses a microwave radar host computer for surveying water instrument, including the emission unit of the continuous single -frequency microwave signal of transmission, in succession power detection unit, single -frequency microwave signal and the beacon signal quadrature mixing unit that carries out the quadrature mixing in succession of single -frequency microwave signal. The utility model discloses the material that awaits measuring among the test procedure only need be in the radar beam shine in the spatial dimension can, need not the contact with test instrument, do not have special demands to accurate shape, size and the motion state of material, can regard as and carry out the universal method of testing to multiple material water content in various industrial application occasions. The utility model discloses a data processing method is based on containing the compound dielectric constant model of 3 kinds of mixed media of composition of material medium, water and air and the dielectric relaxation model of water, adopt dual -frenquency test and make full use of radar signal's range and phase information, and it can reach below 0.1% to test the error to the measuring accuracy does not receive the influence of air content in the material, has good measuring accuracy and uniformity to loose materials such as fibre, cereal, medicinal materials.

Description

For the microwave radar main frame of ice detector device

Technical field

The utility model relates to surveys water device, be a kind of can the radar type microwave water measurer of widespread use in industry, agricultural and the industry such as medical, be used for carrying out quick, contactless, accurate on-line measurement to the water percentage of the material number percent of water weight and material general assembly (TW) (in the material).

Background technology

In industry, agricultural and the industry such as medical, need accurately measure and control to the water percentage of the materials such as building materials, crops, cereal, yarn fabric, medical starting material, product quality could be controlled better.Material moisture measuring method conventional at present has heat drying weight method, infrared reflectivity aquametry, microwave resonance cell method, microwave transmission method etc.Heat drying weight method is GB measuring method, precision is high, but measuring speed is slow, can only test a small amount of sample water percentage, online test fast can not be used for, and only reflect the water cut of sample, because material moisture is usual and uneven, may there is deviation in the average moisture content of sample moisture content and true material, therefore will reflect that the average moisture content of true material needs repeatedly sampling and measuring to carry out statistical study, test period is long, and efficiency is low.Infrared reflectivity aquametry utilizes different moisture content sample to the difference of specific wavelength infrared reflection rate, inverting sample moisture content is carried out by measuring infrared reflectivity, may be used for on-line testing, but because infrared ray is mainly at material surface reflection, little to the penetration depth of material, therefore be mainly used in measuring material top layer water cut, be difficult to the accurate survey water carrying out material body water content.Microwave resonance cell method is placed near water-containing materials by microwave cavity, water-containing materials produces perturbation to resonator cavity and makes resonance frequency shift, because the difference in dielectric constant of the material of different moisture content is comparatively large, therefore to the material of different moisture content, the frequency offset of microwave cavity is different.Microwave cavity is accessed microwave oscillator loop, the deviation inverting according to microwave oscillation signal frequency and nominal value obtains material water ratio.Microwave resonance cell method also only reflects the material moisture near resonator usually, material ensemble average water percentage situation can not be reflected, and must ensure that material and resonator cavity have specific relative position relation guarantee measuring accuracy, in such as test process, material surface need remain close contact with resonator cavity test surfaces, this all has higher requirements to material form, sample size, motion state and equipment installation site, is subject to more restriction in actual applications.

Utility model content

The purpose of this utility model is to provide a kind of microwave radar main frame for ice detector device, has the non-contact type of good measuring accuracy and stronger versatility, Quick material average body water cut test technology.

The purpose of this utility model is achieved through the following technical solutions:

For the microwave radar main frame of ice detector device, the power detecting unit, continuously single-frequency microwave signal and the beacon signal that comprise transmitter unit, continuously the single-frequency microwave signal of launching continuous single-frequency microwave signal carry out the quadrature downconvert unit of quadrature downconvert.

Described transmitter unit comprises the switch driver A, single-pole double-throw switch (SPDT), directional coupler A, the emitting antenna that link in turn; Switch driver A is by the control of frequency selection signal, single-pole double-throw switch (SPDT) is by the control of switch driver A, the output signal that directional coupler A receives single-pole double-throw switch (SPDT) generates continuous single-frequency microwave signal to emitting antenna, single-pole double-throw switch (SPDT) is also by the control of frequency of phase locking source A and frequency of phase locking source B, the vibration signal of frequency of phase locking source A and frequency of phase locking source B all receiving crystal oscillator, crystal oscillator sends reference clock signal to data processing terminal simultaneously.

Power detecting unit comprises the directional coupler B, wave detector, the amplifier that link in turn, and directional coupler B receives the continuous single-frequency microwave signal of transmitter unit.

Quadrature downconvert unit comprises the receiving antenna linked in turn, low noise amplifier, orthogonal mixer, orthogonal mixer receives the continuous single-frequency microwave signal of transmitter unit or the continuous single-frequency microwave signal of received power detecting unit, receiving antenna receives the beacon signal that marker sends, beacon signal carries out quadrature downconvert by orthogonal mixer and continuous single-frequency microwave signal after the amplification of low noise amplifier, orthogonal mixer exports 2 road quadrature mixing signals, one road quadrature mixing signals outputs to intermediate-frequency filter A, intermediate frequency in-phase component signal is exported to data processing terminal again through intermediate frequency amplifier A, another road quadrature mixing signals outputs to intermediate-frequency filter B, intermediate frequency quadrature component signal is exported to data processing terminal again through intermediate frequency amplifier B.

Radar type microwave water measurer device, comprises with lower component:

Gantry base: for placing material sample to be measured;

Microwave radar main frame: for launching continuous single-frequency microwave signal in order to transmission material sample to be measured, and the beacon signal receiving marker transmitting, and output data are sent to data processing terminal;

Marker: for receiving the microwave signal after transmission material sample to be measured, and the microwave signal received is carried out modulation formation beacon signal, and beacon signal is transmitted into microwave radar main frame;

Data processing terminal: data processing terminal output frequency selects signal to microwave radar main frame, microwave radar main frame exports the continuous single-frequency microwave signal of corresponding frequencies according to frequency selection signal, and data processing terminal is also for receiving the output data of microwave radar main frame and calculating the water cut of material sample to be measured.

According to each device above-mentioned, principle of work of the present utility model is: material sample to be measured is placed between microwave radar main frame and marker, during test, under data processing terminal controls, radar emission launches the continuous single-frequency microwave signal of two frequencies successively, after continuous single-frequency microwave signal transmission material sample to be measured, carry out modulation after continuous single-frequency microwave signal is received by marker and form beacon signal, marker also forwards beacon signal, received by microwave radar main frame after beacon signal transmission material sample to be measured, after microwave radar main frame receives beacon signal at every turn, test the in-phase component (I) of beacon signal relative to continuous single-frequency microwave signal and the amplitude of quadrature component (Q) respectively, and by I, Q amplitude information is transferred to data processing terminal and processes.

In data processing terminal, based on comprising material medium, the complex permittivity model of water and air 3 kinds of composition blending agents and the dielectric relaxation model of water, the system calibration parameter utilizing I, Q amplitude information in two continuous single-frequency microwave signal frequency and prestore, process obtains material medium and water weight ratio in blending agent, thus obtain material body water content, namely the weight of water accounts for water-containing materials percentage by weight, and measuring accuracy can reach 0.1%.

Described output data comprise the power detection signal of reference clock signal, continuously single-frequency microwave signal, also comprise the intermediate frequency in-phase component exported after continuous single-frequency microwave signal and beacon signal carry out quadrature downconvert, also comprise the intermediate frequency quadrature component exported after continuous single-frequency microwave signal and beacon signal carry out quadrature downconvert.

From a structural point: microwave radar main frame is positioned at directly over gantry base, marker is positioned at immediately below microwave radar main frame, marker is arranged in gantry base, the microwave radar antenna surface of microwave radar main frame is to gantry base, the marker antenna surface of marker is to microwave radar main frame, the frequency selection signal output terminal of data processing terminal is connected with the frequency selection signal end of microwave radar main frame, and the output data terminal of microwave radar main frame is connected with the data input pin of data processing terminal.

In said structure, also comprise the unified frame be arranged in gantry base, microwave radar main frame is arranged on unified frame, and data processing terminal is also arranged on unified frame.

Preferably, gantry base has groove, and the marker antenna of marker and marker is all arranged in groove.

Marker will realize the microwave signal after receiving transmission material sample to be measured, and the microwave signal received is carried out modulation formation beacon signal, and beacon signal is transmitted into microwave radar main frame, therefore preferred described marker comprises battery, switch driver B, square-wave oscillator, reflection type microwave single-pole single-throw switch (SPST), matched load, battery all with switch driver B, square-wave oscillator is for electrical connection, switch driver B and reflection type microwave single-pole single-throw switch (SPST) carry out driving and are connected, square-wave oscillator mates with switch driver B and is connected, reflection type microwave single-pole single-throw switch (SPST) mates with matched load and is connected, reflection type microwave single-pole single-throw switch (SPST) is also connected with the marker antenna of marker.

Preferably, described microwave radar main frame comprises the quadrature downconvert unit that the power detecting unit of transmitter unit, continuously the single-frequency microwave signal of launching continuous single-frequency microwave signal, continuous single-frequency microwave signal and beacon signal carry out quadrature downconvert.

Preferably, described transmitter unit comprises the switch driver A, single-pole double-throw switch (SPDT), directional coupler A, the emitting antenna that link in turn; Switch driver A is by the control of frequency selection signal, single-pole double-throw switch (SPDT) is by the control of switch driver A, the output signal that directional coupler A receives single-pole double-throw switch (SPDT) generates continuous single-frequency microwave signal to emitting antenna, single-pole double-throw switch (SPDT) is also by the control of frequency of phase locking source A and frequency of phase locking source B, the vibration signal of frequency of phase locking source A and frequency of phase locking source B all receiving crystal oscillator, crystal oscillator sends reference clock signal to data processing terminal simultaneously.

Preferably, power detecting unit comprises the directional coupler B, wave detector, the amplifier that link in turn, and directional coupler B receives the continuous single-frequency microwave signal of transmitter unit.

Preferably, quadrature downconvert unit comprises the receiving antenna linked in turn, low noise amplifier, orthogonal mixer, orthogonal mixer receives the continuous single-frequency microwave signal of transmitter unit or the continuous single-frequency microwave signal of received power detecting unit, receiving antenna receives the beacon signal that marker sends, beacon signal carries out quadrature downconvert by orthogonal mixer and continuous single-frequency microwave signal after the amplification of low noise amplifier, orthogonal mixer exports 2 road quadrature mixing signals, one road quadrature mixing signals outputs to intermediate-frequency filter A, intermediate frequency in-phase component signal is exported to data processing terminal again through intermediate frequency amplifier A, another road quadrature mixing signals outputs to intermediate-frequency filter B, intermediate frequency quadrature component signal is exported to data processing terminal again through intermediate frequency amplifier B.

Advantage of the present utility model is as follows: it is a kind of contactless survey water scheme that the microwave radar transmission-type that the utility model adopts surveys water scheme, in test process, material to be measured only need be in radar beam irradiation spatial dimension, without the need to contacting with testing tool, the accurate shape of material, size and motion state are not specially required, can be used as the universal method of various materials water cut being tested in various industrial applications.Data processing method of the present utility model is based on comprising material medium, the complex permittivity model of water and air 3 kinds of composition blending agents and the dielectric relaxation model of water, double frequency is adopted to test and make full use of amplitude and the phase information of radar signal, test error can reach less than 0.1%, and measuring accuracy by the impact of air content in material, does not have good measuring accuracy and consistance for bulk materials such as fiber, cereal, medicinal materials.It is very simple that microwave radar transmission-type of the present utility model surveys the calibration of water scheme system, only need carry out primary calibration test to a class material sample, to the shape of the sample of calibration testing, size, density without particular/special requirement.The utility model microwave radar transmission-type surveys water scheme, test result is the average body water percentage (weight ratio) of tested material, compared with only testing material top layer water percentage with method of testings such as traditional microwave cavities, the moisture situation of tested material can be reflected more accurately, Test Application requirement widely can be adapted to.The utility model test speed is very fast, and a test duration is less than 1ms, can meet the quick, real-time of the material moisture under delivery status and on-line testing demand.

Accompanying drawing explanation

Fig. 1 is schematic diagram of the present utility model.

Fig. 2 is microwave radar host circuit block diagram.

Fig. 3 is the circuit block diagram of marker.

Reference numeral in figure is expressed as: 1, microwave radar main frame, and 2, microwave radar antenna, 3, marker, 4, marker antenna, 5, data processing terminal, 6, unified frame, 7, gantry base, 8, material sample to be measured.

Embodiment

Below in conjunction with embodiment and accompanying drawing, the utility model is described in further detail, but embodiment of the present utility model is not limited thereto.

Embodiment 1:

As shown in Figure 1, for the microwave radar main frame of ice detector device, comprise gantry base 7, microwave radar main frame 1, marker 3, data processing terminal 5,

Gantry base 7: for placing material sample 8 to be measured;

Microwave radar main frame 1: for launching continuous single-frequency microwave signal in order to transmission material sample 8 to be measured, and the beacon signal receiving marker 3 transmitting, and output data are sent to data processing terminal 5;

Marker 3: for receiving the microwave signal after transmission material sample 8 to be measured, and the microwave signal received is carried out modulation formation beacon signal, and beacon signal is transmitted into microwave radar main frame 1;

Data processing terminal: data processing terminal output frequency selects signal to microwave radar main frame 1, microwave radar main frame 1 exports the continuous single-frequency microwave signal of corresponding frequencies according to frequency selection signal, and data processing terminal is also for receiving the output data of microwave radar main frame 1 and calculating the water cut of material sample to be measured.

Described output data comprise the power detection signal of reference clock signal, continuously single-frequency microwave signal, also comprise the intermediate frequency in-phase component exported after continuous single-frequency microwave signal and beacon signal carry out quadrature downconvert, also comprise the intermediate frequency quadrature component exported after continuous single-frequency microwave signal and beacon signal carry out quadrature downconvert.

According to each device above-mentioned, principle of work of the present utility model is: material sample to be measured is placed between microwave radar main frame and marker, during test, under data processing terminal controls, radar emission launches the continuous single-frequency microwave signal of two frequencies successively, after continuous single-frequency microwave signal transmission material sample to be measured, continuous single-frequency microwave signal is carried out modulation and is formed beacon signal after being received by marker 3, marker 3 also forwards beacon signal, received by microwave radar main frame after beacon signal transmission material sample to be measured, after microwave radar main frame receives beacon signal at every turn, test the in-phase component (I) of beacon signal relative to continuous single-frequency microwave signal and the amplitude of quadrature component (Q) respectively, and by I, Q amplitude information is transferred to data processing terminal 5 and processes.In data processing terminal 5, based on comprising material medium, the complex permittivity model of water and air 3 kinds of composition blending agents and the dielectric relaxation model of water, the system calibration parameter utilizing I, Q amplitude information in two continuous single-frequency microwave signal frequency and prestore, process obtains material medium and water weight ratio in blending agent, thus obtain material body water content, namely the weight of water accounts for water-containing materials percentage by weight, and measuring accuracy can reach 0.1%.

As shown in Figure 1, from a structural point: microwave radar main frame is positioned at directly over gantry base 7, marker 3 is positioned at immediately below microwave radar main frame, marker 3 is arranged in gantry base 7, the microwave radar antenna 2 of microwave radar main frame 1 is towards gantry base, the marker antenna 4 of marker 3 is towards microwave radar main frame, the frequency selection signal output terminal of data processing terminal 5 is connected with the frequency selection signal end of microwave radar main frame 1, and the output data terminal of microwave radar main frame 1 is connected with the data input pin of data processing terminal 5.In said structure, also comprise the unified frame 6 be arranged in gantry base 7, microwave radar main frame is arranged on unified frame 6, and data processing terminal 5 is also arranged on unified frame 6.Preferably, gantry base 7 has groove, and the marker antenna 4 of marker 3 and marker 3 is all arranged in groove.

As shown in Figure 3: marker 3 will realize the microwave signal after receiving transmission material sample 8 to be measured, and the microwave signal received is carried out modulation formation beacon signal, and beacon signal is transmitted into microwave radar main frame 1, therefore preferred described marker 3 comprises battery, switch driver B, square-wave oscillator, reflection type microwave single-pole single-throw switch (SPST), matched load, battery all with switch driver B, square-wave oscillator is for electrical connection, switch driver B and reflection type microwave single-pole single-throw switch (SPST) carry out driving and are connected, square-wave oscillator mates with switch driver B and is connected, reflection type microwave single-pole single-throw switch (SPST) mates with matched load and is connected, reflection type microwave single-pole single-throw switch (SPST) is also connected with the marker antenna 4 of marker 3.

As shown in Figure 2, preferably, described microwave radar main frame comprises the quadrature downconvert unit that the power detecting unit of transmitter unit, continuously the single-frequency microwave signal of launching continuous single-frequency microwave signal, continuous single-frequency microwave signal and beacon signal carry out quadrature downconvert.Preferably, described transmitter unit comprises the switch driver A, single-pole double-throw switch (SPDT), directional coupler A, the emitting antenna that link in turn; Switch driver A is by the control of frequency selection signal, single-pole double-throw switch (SPDT) is by the control of switch driver A, the output signal that directional coupler A receives single-pole double-throw switch (SPDT) generates continuous single-frequency microwave signal to emitting antenna, single-pole double-throw switch (SPDT) is also by the control of frequency of phase locking source A and frequency of phase locking source B, the vibration signal of frequency of phase locking source A and frequency of phase locking source B all receiving crystal oscillator, crystal oscillator sends reference clock signal to data processing terminal simultaneously.Preferably, power detecting unit comprises the directional coupler B, wave detector, the amplifier that link in turn, and directional coupler B receives the continuous single-frequency microwave signal of transmitter unit.Preferably, quadrature downconvert unit comprises the receiving antenna linked in turn, low noise amplifier, orthogonal mixer, orthogonal mixer receives the continuous single-frequency microwave signal of transmitter unit or the continuous single-frequency microwave signal of received power detecting unit, receiving antenna receives the beacon signal that marker 3 sends, beacon signal carries out quadrature downconvert by orthogonal mixer and continuous single-frequency microwave signal after the amplification of low noise amplifier, orthogonal mixer exports 2 road quadrature mixing signals, one road quadrature mixing signals outputs to intermediate-frequency filter A, intermediate frequency in-phase component signal is exported to data processing terminal again through intermediate frequency amplifier A, another road quadrature mixing signals outputs to intermediate-frequency filter B, intermediate frequency quadrature component signal is exported to data processing terminal again through intermediate frequency amplifier B.Microwave radar antenna 2 comprises above-mentioned receiving antenna and emitting antenna.

Water cut measuring method for the microwave radar main frame of ice detector device is:

The first step: the distance calculated between microwave radar antenna 2 and marker antenna 4 exit face is that R, R can Accurate Determinings.

Second step: calibration testing obtains dimensionless system constants.

The concrete steps of calibration testing are as follows:

When there is no material sample, the frequency f that microwave radar main frame 1 is launched successively ₁and f ₂(f ₁<f ₂) microwave signal carry out calibration testing.If frequency is f _itime (i=1,2), microwave radar emissive power is P _ti, the antenna gain G of microwave radar antenna 2 _i, the antenna gain of marker antenna (4) is G _ai, the in-phase component of the beacon signal that microwave radar receives and quadrature amplitude are respectively I _iand Q _i, then:

I _i=A _icos Φ _i(formula 1);

Q _i=A _isin Φ _i(formula 2);

Wherein A _ithe absolute value of the beacon signal amplitude received, Φ _ibe beacon signal relative to the phase place transmitted, and to have:

$A_i^2=P_{\mathrm{ti}}\frac{G_i^2{G}_{\mathrm{ai}}^2{\mathrm{\&lambda;}}_{0i}^4}{{\left(4\mathrm{\&pi;R}\right)}^4}{L}_{0i}{Z}_0$ (formula 3);

${\mathrm{\&Phi;}}_i={\mathrm{\&Phi;}}_{0i}-\frac{4\mathrm{\&pi;}}{{\mathrm{\&lambda;}}_{0i}}R$ (formula 4);

In formula, λ _0ibe frequency be f _ielectromagnetic vacuum wavelength, L _0i, Φ _0ifrequency f respectively _iupper system inherent loss Summing Factor transmission phase place, Z ₀=50 Ω are line characteristic impedances.

Transmit by coupling mechanism coupling unit power, detection produces monitoring voltage V _ifor:

$V_i=k_i\sqrt{Z_0{P}_{\mathrm{ti}}}$ (formula 5);

K _iit is scale-up factor.

So can obtain:

$\frac{I_i}{V_i}=\frac{G_i{G}_{\mathrm{ai}}{\mathrm{\&lambda;}}_{0i}^2}{k_i{\left(4\mathrm{\&pi;R}\right)}^2}\sqrt{L_{0i}}\cos {\mathrm{\&Phi;}}_i$ (formula 6);

$\frac{Q_i}{V_i}=\frac{G_i{G}_{\mathrm{ai}}{\mathrm{\&lambda;}}_{0i}^2}{k_i{\left(4\mathrm{\&pi;R}\right)}^2}\sqrt{L_{0i}}\sin {\mathrm{\&Phi;}}_i$ (formula 7);

When system is the Wide-Band Design, and f ₁and f ₂meet:

$|f_1-f_2|<<\frac{f_1+f_2}{2}$ (formula 8);

Then approximate have k ₁=k ₂=k, L ₀₁=L ₀₂=L ₀, Φ ₀₁=Φ ₀₂=Φ ₀,

Have general antenna:

$G_i=\frac{4\mathrm{\&pi;A}}{{\mathrm{\&lambda;}}_{0i}^2}$ (formula 9);

$G_{\mathrm{ai}}=\frac{4\mathrm{\&pi;}{A}_a}{{\mathrm{\&lambda;}}_{0i}^2}$ (formula 10);

Wherein, A, A _abe the useful area of radar antenna and marker antenna respectively, in system operating band, be approximately constant.

Therefore approximate to have:

$x_i=\frac{I_i}{V_i}=k_0\frac{R^2}{{\mathrm{\&lambda;}}_{0i}^2}\cos ({\mathrm{\&Phi;}}_0-\frac{4\mathrm{\&pi;R}}{{\mathrm{\&lambda;}}_{0i}})$ (formula 11);

$y_i=\frac{Q_i}{V_i}=k_0\frac{R^2}{{\mathrm{\&lambda;}}_{0i}^2}\sin ({\mathrm{\&Phi;}}_0-\frac{4\mathrm{\&pi;R}}{{\mathrm{\&lambda;}}_{0i}})$ (formula 12);

Wherein $k_0=\frac{\sqrt{L_0}{\mathrm{AA}}_a}{{\mathrm{kR}}^4}$ Dimensionless system constants.

3rd step: material sample determination to be measured, obtains.

The concrete steps of material sample determination to be measured are as follows: after being placed with material sample to be measured, equally in frequency f ₁and f ₂carry out twice test, in frequency f _ithe in-phase component of the beacon signal that Shi Leida receives and quadrature amplitude are respectively I _i' and Q _i', similarly to obtain:

$X_i=\frac{I_i^{\&prime;}}{V_i}=k_0\frac{R^2}{{\mathrm{\&lambda;}}_{0i}^2}{e}^{-2{\mathrm{\&alpha;}}_{i}R}\cos ({\mathrm{\&Phi;}}_0-2{\mathrm{\&beta;}}_{i}R)$ (formula 13);

$Y_i=\frac{Q_i^{\&prime;}}{V_i}=k_0\frac{R^2}{{\mathrm{\&lambda;}}_{0i}^2}{e}^{-2{\mathrm{\&alpha;}}_{i}R}\sin ({\mathrm{\&Phi;}}_0-2{\mathrm{\&beta;}}_{i}R)$ (formula 14);

In formula, β _i, α _ithat when there is material sample, frequency is f respectively _ithe complex propagation constant γ of electromagnetic wave in space _ireal part and imaginary part, and to have:

${\mathrm{\&gamma;}}_i={\mathrm{\&beta;}}_i+j{\mathrm{\&alpha;}}_i=\frac{2\mathrm{\&pi;}}{{\mathrm{\&lambda;}}_{0i}}{({\mathrm{\&epsiv;}}_{\mathrm{ci}}^{\&prime;}-j{\mathrm{\&epsiv;}}_{\mathrm{ci}}^{\&prime;\&prime;})}^{\frac{1}{2}}$ (formula 15);

ε in formula _ci', ε _ci" and be that under having material sample situation, frequency is f respectively _itime, the real part of medium complex permittivity and imaginary part on Electromagnetic Wave Propagation path.

According to known quantity x _i, y _i, X _iand Y _iα can be solved _i:

${\mathrm{\&alpha;}}_i=\frac{1}{2R}\ln \frac{x_i^2+y_i^2}{X_i^2+Y_i^2}$ (formula 16);

And try to achieve:

$\cos (\frac{2\mathrm{\&pi;}}{{\mathrm{\&lambda;}}_{0i}}-{\mathrm{\&beta;}}_i)2R=\frac{X_i^{\&prime;}{x}_i+Y_i^{\&prime;}{y}_i}{x_i^2+y_i^2}$ (formula 17);

$\sin (\frac{2\mathrm{\&pi;}}{{\mathrm{\&lambda;}}_{0i}}-{\mathrm{\&beta;}}_i)2R=\frac{Y_i^{\&prime;}{x}_i+X_i^{\&prime;}{y}_i}{x_i^2+y_i^2}$ (formula 18);

If angle φ _i(0≤φ _i< 2 π) meet $\cos {\mathrm{\&phi;}}_i=\frac{X_i^{\&prime;}{x}_i+Y_i^{\&prime;}{y}_i}{x_i^2+y_i^2}$ With $\sin {\mathrm{\&phi;}}_i=\frac{Y_i^{\&prime;}{x}_i-X_i^{\&prime;}{y}_i}{x_i^2+y_i^2},$ Then have:

$(\frac{2\mathrm{\&pi;}}{{\mathrm{\&lambda;}}_{0i}}-{\mathrm{\&beta;}}_i)2R={\mathrm{\&phi;}}_i-2n_i\mathrm{\&pi;}$ (formula 19);

N _iit is a certain positive integer.

Therefore have:

${\mathrm{\&beta;}}_i=\frac{2\mathrm{\&pi;}}{{\mathrm{\&lambda;}}_{0i}}+\frac{2n_i\mathrm{\&pi;}-\mathrm{\&phi;}}{2R}$ (formula 20);

Under satisfied (formula 8) condition, be similar to and can think that electromagnetic wave is in frequency f ₁and f ₂upper group velocity is equal, and the electromagnetic transmission time is also equal, if the two difference v _gfor and τ _d:

${\mathrm{\&tau;}}_d=\frac{2R}{v_g}=\frac{2R}{v_g}=\frac{R}{\mathrm{\&pi;}}\frac{{\mathrm{\&beta;}}_1-{\mathrm{\&beta;}}_2}{f_1-f_2}=\frac{2R}{C}+\frac{2\mathrm{m\&pi;}+{\mathrm{\&phi;}}_1-{\mathrm{\&phi;}}_2}{2\mathrm{\&pi;}(f_2-f_1)}$ (formula 21);

In (formula 21), C is the light velocity in air.

When satisfying condition:

$|f_1-f_2|<\frac{C}{2R\sqrt{{\left|{\mathrm{\&epsiv;}}_c\right|}_{\max }}}$ (formula 22);

Time, in (formula 21), m value meets:

$m=\left\{\begin{array}{cc}0& ({\mathrm{\&phi;}}_1>{\mathrm{\&phi;}}_2)\\ 1& ({\mathrm{\&phi;}}_1\&le;{\mathrm{\&phi;}}_2)\end{array}\right.$ (formula 23);

(formula 22) | ε _c| _maxthat water-containing materials is in frequency f ₁or f ₂the maximal value of upper complex permittivity modulus value.τ is tried to achieve according to m substitution (formula 21) that (formula 23) obtains _dafter, can n be obtained _ivalue be:

N ₁=fix (f ₁τ _d), n ₂=n ₁+ m (formula 24);

(formula 24) substitutes into (formula 20) can in the hope of β _i.According to (formula 15), obtain ε _ci', ε _ci":

${\mathrm{\&epsiv;}}_{\mathrm{ci}}^{\&prime;}={\left(\frac{2\mathrm{\&pi;}}{{\mathrm{\&lambda;}}_{0i}}\right)}^{-2}({\mathrm{\&beta;}}_i^2-{\mathrm{\&alpha;}}_i^2)$ (formula 25);

${\mathrm{\&epsiv;}}_{\mathrm{ci}}^{\&prime;\&prime;}=2{\left(\frac{2\mathrm{\&pi;}}{{\mathrm{\&lambda;}}_{0i}}\right)}^{-2}{\mathrm{\&beta;}}_i{\mathrm{\&alpha;}}_i$ (formula 26);

If the volume ratio of the air in Electromagnetic Wave Propagation space, dried material and water is respectively p:q:r, p+q+r=1, then:

ε ' _ci-j ε " _ci=p ε _a+ q ε _d+ r ε _wi(formula 27);

ε in formula _a, ε _d, ε _withe specific inductive capacity of air, dried material and water respectively, ε _a≈ 1, p+q+r=1.Usual dried material does not have dielectric loss, therefore ε _dfor arithmetic number.

So:

ε ' _ci-1-j ε " _ci=q (ε _d-1)+r (ε _wi-1) (formula 28);

According to the dielectric relaxation model of water, the specific inductive capacity of water is:

${\mathrm{\&epsiv;}}_{\mathrm{wi}}={\mathrm{\&epsiv;}}_{\mathrm{wi}}^{\&prime;}-j{\mathrm{\&epsiv;}}_{\mathrm{wi}}^{\&prime;\&prime;}={\mathrm{\&epsiv;}}_{\&infin;}+\frac{{\mathrm{\&epsiv;}}_s-{\mathrm{\&epsiv;}}_{\&infin;}}{1+j2\mathrm{\&pi;}{f}_i\mathrm{\&tau;}}$ (formula 29);

Wherein ε _s≈ 80 and ε _∞≈ 4.9 is direct current and the infinite height frequency specific inductive capacity of water respectively.τ is the dielectric relaxation time of water, pure water τ ≈ 2 × 10 ^-11s, has different values to the water τ be contained in different material.ε _wireal part and imaginary part be respectively:

${\mathrm{\&epsiv;}}_{\mathrm{wi}}^{\&prime;}={\mathrm{\&epsiv;}}_{\&infin;}+\frac{{\mathrm{\&epsiv;}}_s-{\mathrm{\&epsiv;}}_{\&infin;}}{1+{\left(2\mathrm{\&pi;}{f}_i\mathrm{\&tau;}\right)}^2}$ (formula 30);

${\mathrm{\&epsiv;}}_{\mathrm{wi}}^{\&prime;\&prime;}=\frac{{\mathrm{\&epsiv;}}_s-{\mathrm{\&epsiv;}}_{\&infin;}}{1+{\left(2\mathrm{\&pi;}{f}_i\mathrm{\&tau;}\right)}^2}2\mathrm{\&pi;}{f}_i\mathrm{\&tau;}$ (formula 31);

If

$\stackrel{\&OverBar;}{\mathrm{\&epsiv;}}=q({\mathrm{\&epsiv;}}_d-1)+r({\mathrm{\&epsiv;}}_{\&infin;}-1)$ (formula 32);

Equal respectively with imaginary part according to (formula 28) real part, and (formula 29), (formula 32) are substituted into, can obtain:

${\mathrm{\&epsiv;}}_{\mathrm{ci}}^{\&prime;}-1-\stackrel{\&OverBar;}{\mathrm{\&epsiv;}}=r({\mathrm{\&epsiv;}}_{\mathrm{wi}}^{\&prime;}-{\mathrm{\&epsiv;}}_{\&infin;})=r\frac{{\mathrm{\&epsiv;}}_s-{\mathrm{\&epsiv;}}_{\&infin;}}{1+{\left(2\mathrm{\&pi;}{f}_i\mathrm{\&tau;}\right)}^2}$ (formula 33);

${\mathrm{\&epsiv;}}_{\mathrm{ci}}^{\&prime;\&prime;}=r{\mathrm{\&epsiv;}}_w^{\&prime;\&prime;}=2\mathrm{\&pi;r}{f}_i\mathrm{\&tau;}\frac{{\mathrm{\&epsiv;}}_s-{\mathrm{\&epsiv;}}_{\&infin;}}{1+{\left(2\mathrm{\&pi;}{f}_i\mathrm{\&tau;}\right)}^2}$ (formula 34);

Obtained by (formula 33), (formula 34):

$\frac{{\mathrm{\&epsiv;}}_{\mathrm{ci}}^{\&prime;}-1-\stackrel{\&OverBar;}{\mathrm{\&epsiv;}}}{{\mathrm{\&epsiv;}}_{\mathrm{ci}}^{\&prime;\&prime;}}=2\mathrm{\&pi;}{f}_i\mathrm{\&tau;}$ (formula 35);

According to (formula 35), cancellation parameter τ can obtain:

$\stackrel{\&OverBar;}{\mathrm{\&epsiv;}}=\frac{{\mathrm{\&epsiv;}}_{c1}^{\&prime;}-{\mathrm{b\&epsiv;}}_{c2}^{\&prime;}}{1-b}-1$ (formula 36);

In (formula 36) $b=\frac{f_1{\mathrm{\&epsiv;}}_{c1}^{\&prime;\&prime;}}{f_2{\mathrm{\&epsiv;}}_{c2}^{\&prime;\&prime;}}.$

Be updated to (formula 35), obtain 2 π f _iτ, and substitute into (formula 33) and obtain r; R substitutes into (formula 32) and obtains q (ε _d-1):

$r=\frac{{\mathrm{\&epsiv;}}_{\mathrm{ci}}^{\&prime;}-1-\stackrel{\&OverBar;}{\mathrm{\&epsiv;}}}{{\mathrm{\&epsiv;}}_s-{\mathrm{\&epsiv;}}_{\&infin;}}[1+{\left(\frac{{\mathrm{\&epsiv;}}_{\mathrm{ci}}^{\&prime;}-1-\stackrel{\&OverBar;}{\mathrm{\&epsiv;}}}{{\mathrm{\&epsiv;}}_{\mathrm{ci}}^{\&prime;\&prime;}}\right)}^2]$ (formula 37);

$q({\mathrm{\&epsiv;}}_d-1)=\stackrel{\&OverBar;}{\mathrm{\&epsiv;}}-r({\mathrm{\&epsiv;}}_{\&infin;}-1)$ (formula 38);

According to the volume ratio q:r of dried material and water, can obtain material water ratio w (weight ratio) is:

$w=\frac{r{\mathrm{\&rho;}}_w}{r{\mathrm{\&rho;}}_w+q{\mathrm{\&rho;}}_d}=\frac{r}{r+q({\mathrm{\&epsiv;}}_d-1)\frac{{\mathrm{\&rho;}}_d}{({\mathrm{\&epsiv;}}_d-1){\mathrm{\&rho;}}_w}}=\frac{r}{r+H[\stackrel{\&OverBar;}{\mathrm{\&epsiv;}}-r({\mathrm{\&epsiv;}}_{\&infin;}-1)]}$ (formula 39);

In (formula 39) be dimensionless constant for specific material, its numerical value can be obtained by system calibrating.

4th step: carry out system calibrating,

The specific practice of system calibrating is as follows: (water percentage is non-vanishing to adopt one piece of moisture sample of material, can humidification in advance), first once test with microwave radar ice detector described in the utility model, obtain r by (formula 37), (formula 38) ₀and q ₀(ε _d-1).Then liquid water content standard method of test (according to national standard method of testings such as GB/T462-2003 " mensuration of paper and paperboard moisture content " or GB/T12087-2008 " starch determination of moisture Oven Method ") is adopted to record its accurate water percentage W to this sample ₀.According to (formula 39), can solve:

$H=(\frac{1}{W_0}-1)\frac{r_0}{q_0({\mathrm{\&epsiv;}}_d-1)}$ (formula 40);

After demarcating, namely microwave radar ice detector may be used for such material water ratio on-line testing.Its computation process is served as reasons (formula 16), (formula 20) calculates α _i, β _i, then calculate ε by (formula 25) (formula 26) _ci', ε _ci", calculated by (formula 36), (formula 37) afterwards and r, last basis (formula 39) obtains material moisture.

Water data processing method surveyed by the microwave radar that the utility model proposes is based on comprising material medium, the accurate complex permittivity model of water and air 3 kinds of composition blending agents and the dielectric relaxation theoretical model of water, having theoretic accuracy.The approximate hypothesis that Data processing uniquely may produce error thinks in calibration testing frequency f ₁and f ₂upper system has equal inherent loss Summing Factor transmission phase place.The f when system ₁, f ₂difference is less than 100MHz usually, and (f ₁+ f ₂)/2 generally adopt 20GHz with super band, and relative bandwidth of operation is less than 0.5%, and the error that therefore this hypothesis is introduced can be ignored.

In order to reach the measuring accuracy of more than 0.1%, each component of signal of radargrammetry should possess the amplitude precision of more than 1%.For this reason, according to the measuring distance R of reality, need to ensure that beacon signal that radar receives has the signal to noise ratio (S/N ratio) of more than 40dB, this can by designing suitable radar transmission power to realize.General for 20GHz frequency of operation, measuring distance R=1m, receive noise figure 3dB, receiver noise bandwidth 50kHz, for ensureing that needed for this signal to noise ratio (S/N ratio), emissive power is less than 1mW.Meanwhile, radar emission signal frequency should have due to 10 ^-5above accuracy and degree of stability.

Method of work for the microwave radar main frame of ice detector device can adopt following steps:

1, require (material size, ice detector installing space etc.) according to application, determine required measuring distance;

2, radar operating frequency f is selected with reference to (formula 8), (formula 22) ₁, f ₂, consider system works bandwidth, f ₁, f ₂as get more than Ku frequency range; Select marker switch modulation frequency, the Doppler frequency that its value should produce far above sample motion under test environment, generally get 10 ~ 100kHz;

3, according to installing and using requirement, design radar antenna and marker antenna form, select electromagnetic horn, antenna gain 10 ~ 15dB usually;

4, the measuring distance determined according to step 2 and the determined antenna gain of step 3, design radar transmission power, receive noise figure and receiver noise bandwidth, ensures that the beacon signal signal to noise ratio (S/N ratio) that radar receives is greater than 40dB.Specific design can with reference to radar system equation;

5, according to the determined Radar Design parameter of step 4, radar host computer is built by theory diagram shown in accompanying drawing 2; The parts such as marker are built according to accompanying drawing 3;

6, according to the determined measuring distance of step 2, test sample modes of emplacement and operation display requirement, design integration frame;

7, according to the principle of work of described radar type microwave water measurer and the radar test data processing principle of (formula 1) ~ (formula 40) and system calibrating principle, design data process software;

8, according to radar type microwave water measurer operation display or Test Application requirements for automatic control, man machine operation interface reasonable in design and the interface with host computer and slave computer;

9, carry out software and hardware system integrated, complete radar type microwave water measurer system constructing.

As mentioned above, then well the utility model can be realized.

Claims (4)

1. for the microwave radar main frame of ice detector device, it is characterized in that: the power detecting unit, continuously single-frequency microwave signal and the beacon signal that comprise transmitter unit, continuously the single-frequency microwave signal of launching continuous single-frequency microwave signal carry out the quadrature downconvert unit of quadrature downconvert.

2. the microwave radar main frame for ice detector device according to claim 1, is characterized in that: described transmitter unit comprises the switch driver A, single-pole double-throw switch (SPDT), directional coupler A, the emitting antenna that link in turn; Switch driver A is by the control of frequency selection signal, single-pole double-throw switch (SPDT) is by the control of switch driver A, the output signal that directional coupler A receives single-pole double-throw switch (SPDT) generates continuous single-frequency microwave signal to emitting antenna, single-pole double-throw switch (SPDT) is also by the control of frequency of phase locking source A and frequency of phase locking source B, the vibration signal of frequency of phase locking source A and frequency of phase locking source B all receiving crystal oscillator, crystal oscillator sends reference clock signal simultaneously.

3. the microwave radar main frame for ice detector device according to claim 1, is characterized in that: power detecting unit comprises the directional coupler B, wave detector, the amplifier that link in turn, and directional coupler B receives the continuous single-frequency microwave signal of transmitter unit.

4. the microwave radar main frame for ice detector device according to claim 1, it is characterized in that: quadrature downconvert unit comprises the receiving antenna, low noise amplifier, the orthogonal mixer that link in turn, orthogonal mixer is connected with transmitter unit or power detecting unit, orthogonal mixer exports a road and connects intermediate-frequency filter A, intermediate frequency amplifier A successively, and orthogonal mixer exports another road and connects intermediate-frequency filter B, intermediate frequency amplifier B successively.