CN1952670A - Predicted method of radiation field strength mode of short wave antenna - Google Patents

Abstract

The invention relates to a model prediction method of radiation intensity that is generated by the high power short-wave launching aerial mounted on the complex platform. The method is a proportion iconic model of 1:n according to the real contracture of the short wave antenna and the complex platform; The model prediction measurement system of the short-wave launching aerial radiation intensity is set; the short wave antenna of the iconic model is connected with the model prediction measurement system of the short-wave launching aerial radiation intensity; the signal output from the radiofrequency signal source of the measurement system is fed to the short wave antenna of the iconic model via the radio-frequency power amplifier, the model field intensity measured by the field intensity indicator is acquired, the data processing module software of the testing control computer calls the calibration data and the model field intensity data to calculate the radiation intensity of the real aerial. On the condition of low transmitting power in lab, the radiation intensity that is generated by the high power short-wave launching aerial mounted on the complex platform could be predicted precisely by the calibration of measurement system and the processing of module aerial radiation intensity data.

Description

Predicted method of radiation field strength mode of short wave antenna

Technical field

The present invention relates to a kind of high-power shortwave emitting antenna is loaded into the method that the radiation field intensity that produces after the complex platform carries out model prediction.

Background technology

It is the problem that the complex platform overall design is paid close attention to the most that the radiation field intensity that produces when high-power shortwave emitting antenna is worked on complex platform distributes always, and it directly influences the usage safety performance of personnel, electric initiation device, fuel oil etc.At present, powerful shortwave emitting antenna being loaded into the Forecasting Methodology of the radiation field intensity that produces after the complex platform, mainly is the simulation calculation by Electromagnetic Calculation software, or the radiation field intensity that actual antennas itself produces is measured.Because the structure and the boundary condition complexity of complicated platform such as naval vessel, aircraft when utilizing the electromagnetism software for calculation to calculate, are subjected to the accuracy of computing method and computation model and the restriction of computer capacity, result of calculation and actual conditions error are bigger.And the radiation field intensity that actual antennas produces is measured this method, on the one hand, be difficult to complete artificial antenna back complex platform practical structure environment is installed, and the radiation field distribution that the shortwave emitting antenna produces is subjected to the influence of structural environment very big, therefore because its measurement result of difference of border conditions such as structural environment can not reflect accurately that still short-wave antenna is installed in the electromagnetic field intensity that produces after the actual platform and distributes; On the other hand, measure the radiation field intensity that actual antennas produces, because power is big, the field intensity height can constitute a threat to the healthy and safe of tester.Carry out actual measurement again after platform is built up, if the shortwave radiation field intensity of actual measurement exceeds standard at key position, will revise the platform of building up, this will bother very much, need expend great amount of manpower, time and expense.

Summary of the invention

Technical matters to be solved by this invention is the deficiency that exists at above-mentioned prior art and a kind of predicted method of radiation field strength mode of short wave antenna is provided, this method is carried out under laboratory condition, can not only accurately dope high-power shortwave emitting antenna and be arranged in the radiation field distribution characteristic that produces on the complex platform, and test power is little, the radiation field intensity that produces is less, safe.

The present invention for the technical scheme that problem adopted of the above-mentioned proposition of solution is:

According to the structure of actual short-wave antenna in 1: the ratio of n is made the scale model of short-wave antenna;

According to the structure of the tested complex platform of reality in 1: the ratio of n is made the scale model of complex platform, simultaneously the environment and the boundary condition of complex platform work is all simulated as requested;

Predicted testing system of radiation field strength mode of short wave antenna is set, includes radio-frequency power transmitter unit, field intensity data acquisition unit and test control and three parts of data processing unit;

According to the operating frequency range of actual antennas with contract than coefficient, determine the frequency range and the test frequency number of model test, the frequency of model test be the actual antennas frequency of operation n doubly, the frequency parameter of radio frequency network analyser is set;

The incoming signal loss is carried out calibration measurement, coupling loss is carried out calibration measurement, the reflection coefficient of model antenna is carried out calibration measurement;

The short-wave antenna of scale model is installed complex platform in scale model, the short-wave antenna and the predicted testing system of radiation field strength mode of short wave antenna of scale model join, and the field strength measurement sensor is used for the model field intensity E that the test model antenna produces at the complex platform key position _Mould

Be fed to the short-wave antenna of scale model after the radio-frequency signal source output signal process radio-frequency power amplifier amplification with test macro, test frequency is n a times of actual operating frequency;

The field strength measurement transducer arrangements at the model key position, is gathered the model field intensity that field strength meter is measured,, deposit the test control computer of data processing unit in data file together with the incident power value of network analyzer monitoring;

Change the position of field strength measurement sensor, finish the radiation field intensity at all crucial test point places on the model, and, deposit the test control computer in document form data together with the incident power value that the corresponding network analyser is monitored;

Data processing module software with in the test control computer calls and respectively organizes calibration data and model field intensity data, calculates the radiation field intensity of actual antennas.

Press such scheme, can by the relation form of frequency-field intensity, draw the field strength distribution curve according to the radiation field intensity of the actual antennas that calculates.

Press such scheme, described scale model contract than ratio 1: n be generally 1: 20～50.

Press such scheme, environment to platform work all will be simulated as requested, for sea and ground, available enough big wire netting or sheet metal are simulated, then need to adopt microwave dark room to simulate for free space, platform and antenna part then take metal good conductor (as copper coin) to make, and mainly are to make the bigger platform surface of electromagnetic wave influence, and inner structure can be simplified according to the requirement of mechanical strength of model.

The radio-frequency signal source output power that is fed to the scale model antenna is 20W～50W, and test frequency is n a times of actual operating frequency, and n=20～50 are identical with the ratio n that contracts of scale model.

Adopt network analyzer signal transmission attenuation, coupling loss and three parameters of model antenna reflection coefficient of calibration test system respectively, to finish the calibration to test macro, calibration data deposits computing machine in document format data, calls during for data processing.

Can adopt the radiation power of power meter or spectrum analyzer or receiver monitoring model antenna, simultaneously with the optical fiber field intensity meter measurement model antenna field intensity that each key position produces on platform model.

The mathematic(al) mode of the transformational relation of model aerial radiation field intensity and actual antennas radiation field intensity is:

For calibration in the test process and data processing, the method and the mechanism that are adopted are: utilize radio frequency network analyser in the test macro to be connected to the incoming signal loss L of the cableport (contain directional coupler, isolate attenuator, firing cable) of model antenna respectively in the measuring system from the input port of directional coupler _Incident(dB), the input port of directional coupler meets the coupling loss L of the cableport (radio-frequency cable that contains directional coupler, protection attenuator and coupling channel) of network analyzer receiving end _Coupling(dB), and the voltage reflection coefficient Γ of model antenna, adopt control computer Control Network analyser to carry out sweep measurement, and deposit the data of calibration in computing machine with the form of calibration data file, treat the field intensity E of model antenna ₁After test finishes, call calibration data, and test data is handled, the radiation field intensity E that obtains actual antennas distributes.The ultimate principle that test data is handled is based on Maxwell equation and model antenna theory.Concrete derivation is as follows:

If the electromagnetic field of primary antenna is respectively E and H, coordinate is X, Y, Z, and the time is t, and the parameter of medium is ε, μ, σ; The electromagnetic field of model antenna is respectively E ₁And H ₁, coordinate is X ₁, Y ₁, Z ₁, the time is t ₁, medium parameter is ε ₁, μ ₁, σ ₁, primary antenna is of a size of n times of model antenna size, and then two antennas have following relation:

$\left\{\begin{array}{c}X=n{X}_1,Y=n{Y}_1,Z=n{Z}_1\\ E=a{E}_1,H=b{H}_1,t=c{t}_1\end{array},---\left(1\right)\right.$

In the formula: a, b, c are scale-up factor undetermined, then have:

$\▿=i\frac{\∂}{\∂x}+j\frac{\∂}{\∂y}+k\frac{\∂}{\∂z}=\frac{l}{n}(i\frac{\∂}{{\∂x}_1}+j\frac{\∂}{{\∂y}_1}+k\frac{\∂}{\∂z_1})=\frac{l}{n_{}}{\▿}_l---\left(2\right)$

$\frac{{\∂H}_1}{{\∂t}_1}=\frac{c}{b}\frac{\∂H}{\∂t}$

$\frac{{\∂E}_1}{\∂t_1}=\frac{c}{a}\frac{\∂E}{\∂t}---\left(3\right)$

Because primary antenna and model antenna all should satisfy Maxwell equation, then:

$\▿\×H=\mathrm{\ϵ}\frac{\∂E}{\∂t}+\mathrm{\σE}---\left(4\right)$

$\▿\×E=-\mathrm{\μ}\frac{\∂H}{\∂t}---\left(5\right)$

${\▿}_1\×H_1=\×\frac{l}{b}H=\mathrm{\ϵ}\frac{\mathrm{na}}{\mathrm{bc}}\frac{\∂E_1}{\∂t_1}+\mathrm{\σ}\frac{\mathrm{na}}{b}{E}_1---\left(6\right)$

${\▿}_1\×E_1=n\▿\×\frac{l}{a}E=-\mathrm{\μ}\frac{\mathrm{nb}}{\mathrm{ac}}\frac{{\∂H}_1}{\∂t_1}---\left(7\right)$

As seen, make the electromagnetic field distribution of model antenna have identical form, must make formula (4), (5) have identical form, that is: with formula (6), (7) with the life size antenna

${\mathrm{\σ}}_1=\mathrm{\σ}\frac{\mathrm{na}}{b}---\left(8\right)$

${\mathrm{\μ}}_1=\mathrm{\μ}\frac{\mathrm{nb}}{\mathrm{ac}}---\left(9\right)$

${\mathrm{\ϵ}}_1=\mathrm{\ϵ}\frac{\mathrm{na}}{\mathrm{cb}}---\left(10\right)$

Because primary antenna and model antenna are all made in air and are studied, and adopt identical electromagnetic unit, then

a＝b ε＝ε ₁ μ＝μ ₁ (11)

By formula (8)～(11), can get:

n＝c σ ₁＝nσ (12)

By as can be seen above, if the size of antenna is dwindled n doubly, in order to keep the similarity with primary antenna, should reduce n doubly (or doubly) to the cycle frequency raising n, the conductivity of electrolyte materials of modeling antenna is improved n doubly, because the material of primary antenna and model antenna is the metal of good conductor, its radiation power can be ignored because of not increasing the error that conductivity is introduced much larger than loss power.

Therefore, there is relation as shown in the table between each amount of primary antenna and model antenna:

Mutual relationship between table 1 model antenna and primary antenna amount

Length	l 1＝l/n
		Time	t 1＝t/n
Electric field	E 1＝E/a
		Magnetic field	H 1＝H/b
Voltage	u 1＝u/na
		Electric current	I 1＝I/nb
Frequency	f 1＝nf
		Wavelength	λ 1＝λ/n
Impedance	Z 1＝Z
		Gain function	g 1(θ，φ)＝g(θ，φ)
General power	P 1＝P/abn 2

Because P ₁=P/abn ², a=b

Therefore have: $a=\frac{l}{n}\sqrt{\frac{p}{p_1}}---\left(13\right)$

Promptly $E=a{E}_1=\frac{l}{n}\sqrt{\frac{p}{p_1}}{E}_1---\left(14\right)$

E is the radiation field intensity of actual antennas in the formula, E ₁Be the radiation field intensity of model antenna, P is the radiation power of actual antennas, P ₁Radiation power for the model antenna.The radiation power of actual antennas is the output power P of transmitter _{Go into}Multiply by the efficiency eta of antenna system, be known; The radiation power P of model antenna ₁With model aerial radiation field intensity E ₁Then obtain, thereby calculate the radiation field intensity E that obtains actual antennas by experimental test.To the calibration of test macro is that reflection factor when considering the cable loss of test macro and model antenna because of no antenna tuner is handled test data, to obtain model aerial radiation power P more accurately ₁

If the coupled power that network analyzer is measured is P _{1 coupling}(dBm), then the power input of directional coupler is:

P _{0 input}(dBm)=P _{1 coupling}(dBm)-L _Coupling(dBm) (15)

The power input of model antenna port is:

P _{1 input}(dBm)=P _{0 input}(dBm)+L _Incident(dB)

=P _{1 coupling}(dBm)-L _Coupling(dB)+L _Incident(dB) (16)

Because the voltage reflection coefficient of model antenna is Γ, then reflection coefficient of power is Γ ², then the reflective power of model antenna is:

P _{1 reflection}=P _{1 input}* Γ ²(17)

Make because the model antenna is a good conductor, ignore the thermal losses of antenna, then the radiation power of model antenna is:

P _{1 radiation}(W)=P _{1 input}-P _{1 reflection}=P _{1 input}* (1-Γ ²)

Therefore,

Formula (19) is the transformational relation from model aerial radiation field intensity to the actual antennas radiation field intensity.

The invention has the beneficial effects as follows: 1, can be under laboratory condition, by to the calibration of test macro with to the processing of model aerial radiation field intensity data, after predicting exactly that in the design phase high-power shortwave emitting antenna is arranged in complex platform, the radiation field intensity that produces at key position; 2, the test emissive power is little, and the tester is not constituted the Electromgnetic seat threat; 3, easy to use, testing expense is lower.

Description of drawings

Fig. 1 is the FB(flow block) of one embodiment of the invention.

Fig. 2 is an incoming signal loss calibration measurement block diagram of the present invention.

Fig. 3 is a coupling loss calibration measurement block diagram of the present invention.

Fig. 4 is a model antenna reflection coefficient calibration measurement block diagram of the present invention.

Fig. 5 is the structural principle block diagram of predicted testing system of radiation field strength mode of short wave antenna of the present invention.

Fig. 6 is the field intensity-frequency curve of the model aerial radiation generation that certain test point records on the platform model.

Fig. 7 is converted on the actual platform field intensity-frequency curve that actual antennas radiation that should the test point prediction is produced for calculating according to this method.

Embodiment

The present invention is further described below in conjunction with drawings and embodiments.

1) at first to determine that it is 20 that model contracts than coefficient, adopt good conductors such as copper or galvanized iron sheet to make the scale model of complex platform and antenna according to the frequency of operation of actual antennas and the operating frequency range of testing tool.When making the complex platform model, emphasis considers that making can be simplified according to the model structure needs in platform inside to bigger metallic profiles and the superstructure housing of aerial radiation influence; Model antenna then emphasis is partly simulated the radiator and the feed of antenna, and is installed in the corresponding position of platform model.

2) predicted testing system of radiation field strength mode of short wave antenna is set, include the radio-frequency power transmitter unit, field intensity data acquisition unit and test control and three parts of data processing unit, described radio-frequency power transmitter unit comprises radio frequency network analyser and radio-frequency power amplifier, the radio-frequency power amplifier delivery outlet joins by directional coupler and emitting antenna model, described field intensity data acquisition unit is the high field tester, described data processing unit is the computing machine that test control and data processing software are housed, and radio frequency network analyser and high field tester all link with computing machine.In addition, link by isolating attenuator and emitting antenna model at the directional coupler output terminal; The input coupled end of directional coupler is joined by the receiving end of protection attenuator and radio frequency network analyser; The frequency range of radio frequency network analyser satisfies testing requirements, carry the built-in signal source, its receiving port can carry out absolute power and measure, band computer control and data transmission interface, the radio frequency network analyser also is used for the path loss of total system and the reflection coefficient of antenna are measured and calibrated except signal output and power monitoring; Output power 20～the 50W of radio-frequency power amplifier.Described high field tester is the optical fiber field strength meter, and its sensitivity is less than 1V/m, and the optical fiber field strength meter comprises the field strength measurement sensor.

2) behind the model of making platform and antenna, press Fig. 2, Fig. 3, Fig. 4, calibration and test principle block diagram shown in Figure 5 respectively, connect each testing tool of test macro, make up the calibration and the test macro of model aerial radiation field intensity.Frequency of operation according to actual antennas compares coefficient with contracting, getting actual operating frequency is 2MHz～30MHz, and contracting than coefficient is 1: 20, and then the model test frequency range is 40MHz～600MHz, select certain test frequency number, the frequency parameter of radio frequency network analyser is set.

3) the incoming signal loss is carried out calibration measurement: earlier with two port short circuits of subtest cable 1 with the radio frequency network analyser, set the start-stop frequency of radio frequency network analyser according to the test frequency scope, network analyzer is in the transmission mode of operation, and the radio frequency network analyzer is led directly to calibration; Receiving port from the radio frequency network analyser disconnects subtest cable 1 again; be connected to the input end of directional coupler; the port that test cable 2 is connect the model antenna is connected to the receiving end of radio frequency network analyser, and the coupling port of directional coupler connects matched load (as shown in Figure 2) through the protection attenuator.Measure the loss of incoming signal, and deposit test curve in the test control computer with document form data;

4) coupling loss is carried out calibration measurement: in previous step the radio frequency network analyzer is led directly on the basis of calibration, the terminal of test cable 2 is connect matched load, the coupling port of directional coupler is connected to the receiving end (as shown in Figure 3) of network analyzer through protection attenuator, coupling cable, measure the coupling loss of input signal, and deposit test curve in the test control computer with document form data;

5) reflection coefficient to the model antenna carries out calibration measurement: the signal output port that test cable 2 is connected to the radio frequency network analyser, the radio frequency network analyser is in the reflection measurement state, respectively at another termination open circuit device, short-circuiting device and matched load of test cable 2, radio frequency network analyzer and test cable are calibrated, then test cable 2 is connected to the model antenna, the reflection coefficient of measurement model antenna, represent with linear forms, and deposit test curve in the test control computer with document form data;

6) connecting test macro according to the form of Fig. 5, the power that the radio frequency network analyser is set is output as-2dBm～-10dBm, with the protection radio-frequency power amplifier; After the radiofrequency signal process power amplifier amplification by the output of radio frequency network analyser, deliver to the input end of directional coupler, the output terminal of directional coupler links to each other with the model antenna by radio frequency coaxial-cable, the isolation attenuator that to insert a damping capacity therebetween be 3～SdB, can reduce effectively to improve accuracy of measurement because of antenna does not match the reflected signal that produces to the influence of incident coupling and radio-frequency power amplifier; The incident coupling of directional coupler links to each other with the receiving port of network analyzer by a protection attenuator, with the power input P of monitoring model antenna _{1 goes into}, reflective power is then calculated acquisition by the reflection coefficient and the incident power of antenna; Field test instrument and field strength measurement sensor are used for the model field intensity E that the test model antenna produces at key position _Mould

7) receiving port that the radio frequency network analyser is set is that absolute power is measured state, opens radio-frequency power amplifier.The survey sensor of optical fiber field strength meter is arranged in the model key position, gathers the model field intensity of optical fiber field strength meter measurement and the incident power value of network analyzer monitoring, deposit the test control computer in data file; Field intensity-frequency curve that the model aerial radiation that Fig. 6 records for certain test point on the platform model produces;

8) radiation field intensity at all crucial test point places on the model is finished in the position of change sensor, and with the incident power value that network analyzer is monitored, deposits the test control computer in document form data;

9) utilize data processing module, the main mathematical models of data processing module software is formula (19), calls and respectively organizes calibration data and model field intensity data, calculates the radiation field intensity of actual antennas, and presses the relation form of frequency-field intensity, draws the field strength distribution curve.Test control among Fig. 5 and data acquisition computer are used for controlling frequency and output power, the power monitoring collection of network analyzer receiving port and data acquisition, data-switching and the data processing etc. of field test instrument of radio frequency network analyser.Fig. 7 is converted on the actual platform field intensity-frequency curve that actual antennas radiation that should the test point prediction is produced for calculating according to this method.

Claims (8)

1. a predicted method of radiation field strength mode of short wave antenna is characterized in that

According to the structure of actual short-wave antenna in 1: the ratio of n is made the scale model of short-wave antenna,

According to reality by the structure of side complex platform in 1: the ratio of n is made the scale model of complex platform, simultaneously the environment of complex platform work is all simulated as requested,

Predicted testing system of radiation field strength mode of short wave antenna is set, includes radio-frequency power transmitter unit, field intensity data acquisition unit and test control and three parts of data processing unit,

According to the operating frequency range of actual antennas with contract than coefficient, determine the frequency range and the test frequency number of model test, the frequency of model test be the actual antennas frequency of operation n doubly, the frequency parameter of radio frequency network analyser is set,

The incoming signal loss is carried out calibration measurement, coupling loss is carried out calibration measurement, the reflection coefficient of model antenna is carried out calibration measurement,

The short-wave antenna of scale model is installed complex platform in scale model, the short-wave antenna and the predicted testing system of radiation field strength mode of short wave antenna of scale model join, and the field strength measurement sensor is used for the model field intensity E that the test model antenna produces at the complex platform key position _Mould,

Be fed to the short-wave antenna of scale model after the radio-frequency signal source output signal process radio-frequency power amplifier amplification with test macro, test frequency is n a times of actual operating frequency,

The field strength measurement transducer arrangements at the model key position, is gathered the model field intensity that field strength meter is measured,, deposit the test control computer of data processing unit in data file together with the incident power value of network analyzer monitoring;

Change the position of field strength measurement sensor, finish the radiation field intensity at all crucial test point places on the model, and, deposit the test control computer in document form data together with the incident power value that the corresponding network analyser is monitored;

Data processing module software with in the test control computer calls and respectively organizes calibration data and model field intensity data, calculates the radiation field intensity of actual antennas.

2. predicted method of radiation field strength mode of short wave antenna according to claim 1 is characterized in that the radiation field intensity according to the actual antennas that calculates, and by the relation form of frequency-field intensity, draws the field strength distribution curve.

3. predicted method of radiation field strength mode of short wave antenna according to claim 1, it is characterized in that described scale model to contract than ratio 1: n be 1: 20～50.

4. according to claim 1 or 3 described predicted method of radiation field strength mode of short wave antenna, it is characterized in that all will simulating as requested to the environment of platform work, for sea and ground, simulate with enough big wire netting or sheet metal, then need to adopt microwave dark room to simulate for free space, platform and antenna part then take the metal good conductor to make, and mainly are to make the bigger platform surface of electromagnetic wave influence.

5. according to claim 1 or 3 described predicted method of radiation field strength mode of short wave antenna, the radio-frequency signal source output power that it is characterized in that being fed to the scale model antenna is 20W～50W, test frequency is n a times of actual operating frequency, and n=20～50 are identical with the ratio n that contracts of scale model.

6. according to claim 1 or 3 described predicted method of radiation field strength mode of short wave antenna, it is characterized in that in the described predicted testing system of radiation field strength mode of short wave antenna, the radio-frequency power transmitter unit comprises radio frequency network analyser and radio-frequency power amplifier, the radio-frequency power amplifier delivery outlet joins by directional coupler and emitting antenna model, described field intensity data acquisition unit is the high field tester, described data processing unit is the computing machine that test control and data processing software are housed, radio frequency network analyser and high field tester all link with computing machine, in addition, link by isolating attenuator and emitting antenna model at the directional coupler output terminal; The input coupled end of directional coupler is joined by the receiving end of protection attenuator and radio frequency network analyser.

7. predicted method of radiation field strength mode of short wave antenna according to claim 6, it is characterized in that adopting network analyzer signal transmission attenuation, coupling loss and three parameters of model antenna reflection coefficient of calibration test system respectively, to finish calibration to test macro, calibration data deposits computing machine in document format data, calls during for data processing.

8. predicted method of radiation field strength mode of short wave antenna according to claim 7 is characterized in that the mathematic(al) mode of the transformational relation of model aerial radiation field intensity and actual antennas radiation field intensity is:

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