CN109547130B - Method and device for predicting second-order intermodulation low-frequency blocking effect of out-of-band electromagnetic radiation - Google Patents
Method and device for predicting second-order intermodulation low-frequency blocking effect of out-of-band electromagnetic radiation Download PDFInfo
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Abstract
The invention is suitable for the technical field of electromagnetic environment effect test evaluation, and provides a method and equipment for predicting a second-order intermodulation low-frequency blocking effect of out-of-band electromagnetic radiation, wherein the method comprises the following steps: acquiring the electromagnetic radiation sensitive bandwidth and at least four out-of-band basic frequency points of the tested frequency equipment; performing a second-order intermodulation low-frequency blocking critical interference effect test according to at least four out-of-band basic frequency points, and determining a low-frequency interference level relative value and a second-order intermodulation low-frequency blocking interference factor according to a test result; and establishing a second-order intermodulation low-frequency blocking interference effect model according to the low-frequency interference level relative value and the second-order intermodulation low-frequency blocking interference factor. According to the method and the device for predicting the second-order intermodulation low-frequency blocking effect of the out-of-band electromagnetic radiation, provided by the embodiment of the invention, two important parameters in a model, namely a low-frequency interference level relative value and a second-order intermodulation low-frequency blocking interference factor, are determined in a test mode, so that the quantitative evaluation of the second-order intermodulation interference is realized, and the method and the device are suitable for various frequency devices.
Description
Technical Field
The invention relates to the technical field of electromagnetic environment effect test evaluation, in particular to a method and equipment for predicting a second-order intermodulation low-frequency blocking effect of out-of-band electromagnetic radiation.
Background
The receiving frequency range of the antenna is very wide, strong electromagnetic radiation signals outside the working frequency band of the frequency equipment can also enter the radio frequency front end, and once the three-order intermodulation new frequency of interference signals with different frequencies falls into the working frequency band of the frequency equipment after the signals pass through a series of nonlinear devices such as a limiting filter, a low-noise amplifier, a mixer and the like, the radiation field intensity of the jamming interference of the signals is far lower than the critical field intensity of the jamming interference of a single frequency, and the three-order intermodulation interference has attracted high attention of foreign and domestic scholars. As for the second-order intermodulation interference, it is generally considered that the frequency of the interference signal deviates too far from the operating frequency of the device under test and is often ignored. However, when the frequency difference of the out-of-band electromagnetic radiation interference signal is not large, even under the condition that the second order and third order intermodulation frequencies are far away from the working frequency of the tested equipment, the tested communication station is still much more sensitive to the out-of-band dual-frequency electromagnetic radiation than the single-frequency electromagnetic radiation, and the critical interference field intensity is even different by tens of dB. Therefore, effective prediction of the out-of-band electromagnetic radiation second-order intermodulation low-frequency blocking effect is very important for evaluating the communication safety and reliability.
Disclosure of Invention
In view of this, embodiments of the present invention provide a method and a device for predicting a second-order intermodulation low-frequency blocking effect of out-of-band electromagnetic radiation, so as to solve the problem in the prior art that the second-order intermodulation interference of a frequency-using device is not evaluated.
According to a first aspect, an embodiment of the present invention provides a method for predicting a second-order intermodulation low-frequency blocking effect of out-of-band electromagnetic radiation, including: acquiring an electromagnetic radiation sensitive bandwidth of a tested frequency device and at least four out-of-band basic frequency points outside the electromagnetic radiation sensitive bandwidth; performing a second-order intermodulation low-frequency blocking critical interference effect test according to the at least four out-of-band basic frequency points, and determining the relation between the relative value of the low-frequency interference level and the intermodulation frequency difference and the relation between a second-order intermodulation low-frequency blocking interference factor and the radiation frequency offset according to the test result; and establishing a second-order intermodulation low-frequency blocking interference effect model according to the low-frequency interference level relative value and the second-order intermodulation low-frequency blocking interference factor, and predicting whether the tested frequency equipment has second-order intermodulation low-frequency blocking interference according to the model.
According to the prediction method for the second-order intermodulation low-frequency blocking effect of the out-of-band electromagnetic radiation, provided by the embodiment of the invention, the second-order intermodulation interference of the frequency equipment is evaluated by establishing a second-order intermodulation low-frequency blocking interference effect model. Through a test mode, two important parameters in the model, namely a low-frequency interference level relative value and a value of a second-order intermodulation low-frequency blocking interference factor, are determined, quantitative evaluation of second-order intermodulation interference is achieved, and the method is suitable for various frequency devices.
With reference to the first aspect, in a first implementation manner of the first aspect, the performing a second-order intermodulation low-frequency blocking critical interference effect test according to the at least four out-of-band fundamental frequency points, and determining a relationship between a relative value of a low-frequency interference level and an intermodulation frequency difference, and a relationship between a second-order intermodulation low-frequency blocking interference factor and a radiation frequency offset according to a test result includes: acquiring an extrapolation frequency point, performing a second-order intermodulation low-frequency blocking critical interference effect test according to the extrapolation frequency point and any one of the at least four out-of-band basic frequency points, and acquiring a ratio of a radiation field intensity corresponding to the extrapolation frequency point to a single-frequency critical blocking interference field intensity according to a test result; calculating a second-order intermodulation low-frequency blocking interference factor corresponding to the extrapolated frequency point according to the ratio of the radiation field intensity corresponding to the extrapolated frequency point to the single-frequency critical blocking interference field intensity; calculating low-frequency interference level relative values corresponding to different intermodulation frequency differences according to the second-order intermodulation low-frequency blocking interference factors corresponding to the extrapolated frequency points; and drawing a fitting curve of the low-frequency interference level relative value according to the low-frequency interference level relative value corresponding to the different intermodulation frequency differences.
According to the prediction method for the second-order intermodulation low-frequency blocking effect of the out-of-band electromagnetic radiation, the low-frequency interference level relative values corresponding to different intermodulation frequency differences are calculated in a test mode, and then the low-frequency interference level relative values are applied to quantitative evaluation of the second-order intermodulation interference, so that the communication safety and reliability of frequency equipment are improved.
With reference to the first implementation manner of the first aspect, in a second implementation manner of the first aspect, after the drawing a fitting curve of the relative values of the low-frequency interference levels, the performing a second-order intermodulation low-frequency blocking critical interference effect test according to the at least four out-of-band fundamental frequency points, and determining a relationship between the relative values of the low-frequency interference levels and an intermodulation frequency difference and a relationship between a second-order intermodulation low-frequency blocking interference factor and a radiation frequency offset according to a test result, further includes: acquiring at least four other out-of-band basic frequency points outside the electromagnetic radiation sensitive bandwidth; performing a second-order intermodulation low-frequency blocking critical interference effect test according to the at least four other out-of-band basic frequency points, and calculating second-order intermodulation low-frequency blocking interference factors corresponding to the at least four other out-of-band basic frequency points according to a test result and low-frequency interference level relative values corresponding to the different intermodulation frequency differences; and drawing a fitting curve of the second-order intermodulation low-frequency blocking interference factors according to the second-order intermodulation low-frequency blocking interference factors corresponding to the at least four other out-of-band basic frequency points.
According to the method for predicting the second-order intermodulation low-frequency blocking effect of the out-of-band electromagnetic radiation, the second-order intermodulation low-frequency blocking interference factors corresponding to different radiation frequency offsets are calculated in a test mode, and then the second-order intermodulation low-frequency blocking interference factors are applied to quantitative evaluation of second-order intermodulation interference, so that the communication safety and reliability of frequency equipment are improved.
In combination with the second embodiment of the first aspect, in the third embodiment of the first aspect
Calculating a second-order intermodulation low-frequency blocking interference factor corresponding to the extrapolated frequency point; wherein, β (Δ f)3n+4) Indicating an extrapolated frequency point f3n+4A corresponding second order intermodulation low frequency blocking interference factor; Δ f3n+4Indicating an extrapolated frequency point f3n+4Corresponding deviation of radiation frequency, f3n+4＝f1+3(n +1) omega, n being a natural number, omega representing the spacing of said at least four out-of-band fundamental frequency points, f1Representing a first out-of-band basic frequency point of the at least four out-of-band basic frequency points; l isr(3n Ω) represents a relative value of the low-frequency interference level corresponding to the intermodulation frequency difference of 3n Ω; beta (. DELTA.f)4) Representing a radiation frequency deviation Δ f4Corresponding second order intermodulation low frequency blocking interference factor, radiation frequency deviation delta f4Representing a fourth out-of-band fundamental frequency point f of the at least four out-of-band fundamental frequency points4The radiation frequency offset of (1);
indicating out-of-band fundamental frequency point f4Sum extrapolated frequency point f3n+4And carrying out a second-order intermodulation low-frequency blocking critical interference effect test to obtain a ratio of the radiation field intensity to the single-frequency critical blocking interference field intensity.
According to the method for predicting the second-order intermodulation low-frequency blocking effect of the out-of-band electromagnetic radiation, the second-order intermodulation low-frequency blocking interference factor corresponding to each extrapolated frequency point in the test is calculated through a formula, and then the low-frequency interference level relative values corresponding to different intermodulation frequency differences are calculated, so that the low-frequency interference level relative values are applied to quantitative evaluation of the second-order intermodulation interference, and the communication safety and reliability of frequency equipment are improved.
In combination with the third embodiment of the first aspect, in the fourth embodiment of the first aspect
Calculating low-frequency interference level relative values corresponding to the different intermodulation frequency differences; wherein L isr(3n Ω + Ω) represents a relative value of low-frequency interference levels corresponding to the intermodulation frequency difference (3n Ω + Ω), and Lr(3n Ω + Ω) represents a relative value of low-frequency interference levels corresponding to the intermodulation frequency difference (3n Ω + Ω), and Lr(3n Ω +2 Ω) represents a relative value of low-frequency interference levels corresponding to the intermodulation frequency difference (3n Ω +2 Ω), and Lr(3n Ω +3 Ω) represents a relative value of the low-frequency interference level corresponding to the intermodulation frequency difference (3n Ω +3 Ω); beta (. DELTA.f)1) Representing a radiation frequency deviation Δ f1Corresponding second order intermodulation low frequency blocking interference factor, beta (Δ f)2) Representing a radiation frequency deviation Δ f2Corresponding second order intermodulation low frequency blocking interference factor, beta (Δ f)3) Representing a spokeRadio frequency deviation delta f3Corresponding second order intermodulation low frequency blocking interference factor, beta (Δ f)3n+4) Indicating an extrapolated frequency point f3n+4A corresponding second order intermodulation low frequency blocking interference factor;
indicating out-of-band fundamental frequency point f3Sum extrapolated frequency point f3n+4Carrying out a second-order intermodulation low-frequency blocking critical interference effect test to obtain a ratio of radiation field intensity to single-frequency critical blocking interference field intensity;
indicating out-of-band fundamental frequency point f2Sum extrapolated frequency point f3n+4Carrying out a second-order intermodulation low-frequency blocking critical interference effect test to obtain a ratio of radiation field intensity to single-frequency critical blocking interference field intensity;
indicating out-of-band fundamental frequency point f1Sum extrapolated frequency point f3n+4And carrying out a second-order intermodulation low-frequency blocking critical interference effect test to obtain a ratio of the radiation field intensity to the single-frequency critical blocking interference field intensity.
According to the prediction method for the second-order intermodulation low-frequency blocking effect of the out-of-band electromagnetic radiation, provided by the embodiment of the invention, on the basis of obtaining the second-order intermodulation low-frequency blocking interference factors corresponding to the extrapolation frequency point through calculation, a formula for further calculating the low-frequency interference level relative values corresponding to different intermodulation frequency differences is provided, so that the low-frequency interference level relative values can be applied to quantitative evaluation of the second-order intermodulation interference in subsequent steps, and the communication safety and reliability of frequency equipment are improved.
With reference to the fourth embodiment of the first aspect, in the fifth embodiment of the first aspect
Calculating second-order intermodulation low-frequency blocking interference factors corresponding to the at least four other out-of-band basic frequency points; wherein, β (Δ f)1') denotes the out-of-band fundamental frequency point Δ f1' corresponding second order Intermodulation Low frequency blocking interference factor, beta (Δ f)2') denotes the out-of-band fundamental frequency point Δ f2' corresponding second order Intermodulation Low frequency blocking interference factor, beta (Δ f)3') denotes the out-of-band fundamental frequency point Δ f3' corresponding second order Intermodulation Low frequency blocking interference factor, beta (Δ f)4') denotes the out-of-band fundamental frequency point Δ f4' a corresponding second order intermodulation low frequency blocking interference factor; l isr(2 Ω) represents a relative value of the low-frequency interference level corresponding to the intermodulation frequency difference (2 Ω);
indicating out-of-band fundamental frequency point fi' and fj' ratio of radiation field intensity obtained by carrying out second-order intermodulation low-frequency blocking critical interference effect test to single-frequency critical blocking interference field intensity.
According to the prediction method for the second-order intermodulation low-frequency blocking effect of the out-of-band electromagnetic radiation, provided by the embodiment of the invention, on the basis of obtaining the low-frequency interference level relative value corresponding to the intermodulation frequency difference (2 omega) through calculation, a formula for further calculating the second-order intermodulation low-frequency blocking interference factors corresponding to different radio frequency offsets is provided, so that the second-order intermodulation low-frequency blocking interference factors can be applied to quantitative evaluation of the second-order intermodulation interference in subsequent steps, and the communication safety and reliability of frequency equipment are improved.
According to the first aspect or any one of the first to fifth embodiments of the first aspect, in the sixth embodiment of the first aspect
Establishing a second-order intermodulation low-frequency blocking interference effect model; wherein R is2(fb-fa) Representing a frequency faAnd fbThe second-order intermodulation low-frequency blocking interference effect index corresponding to the out-of-band signal; beta (f)a-f0) Representing a frequency faThe second-order intermodulation low-frequency blocking interference factor corresponding to the out-of-band signal of (f)a-f0) Representing a frequency faRelative to the operating frequency f of the frequency device under test0The radiation frequency offset of (1); beta (f)b-f0) Representing a frequency fbThe second-order intermodulation low-frequency blocking interference factor corresponding to the out-of-band signal of (f)b-f0) Representing a frequency fbRelative to the operating frequency f of the frequency device under test0The radiation frequency offset of (1); l isr(fb-fa) Representing a frequency faAnd fbRelative value of the low-frequency interference level corresponding to the out-of-band signal of (f)b-fa) Representing a frequency faAnd fbInter-modulation frequency difference between the out-of-band signals of (1);
representing a frequency faThe ratio of the radiation field intensity corresponding to the out-of-band signal to the single-frequency critical blocking interference field intensity;
representing a frequency fbThe ratio of the radiation field intensity corresponding to the out-of-band signal to the critical blocking interference field intensity of the single frequency.
According to the method for predicting the second-order intermodulation low-frequency blocking effect of the out-of-band electromagnetic radiation, the frequency of the out-of-band signal is used as a variable, the second-order intermodulation low-frequency blocking interference effect index is used as a dependent variable, the second-order intermodulation interference degree of the out-of-band signal to the frequency-using equipment is judged by calculating the second-order intermodulation low-frequency blocking interference effect indexes corresponding to the out-of-band signals with different frequencies, and quantitative evaluation of the second-order intermodulation interference is achieved.
With reference to the sixth implementation manner of the first aspect, in the seventh implementation manner of the first aspect, after the establishing a second-order intermodulation low-frequency blocking interference effect model according to the relative value of the low-frequency interference level and the second-order intermodulation low-frequency blocking interference factor, the out-of-band electromagnetic radiation second-order intermodulation low-frequency blocking effect prediction method further includes: judging whether the second-order intermodulation low-frequency blocking interference effect index is larger than or equal to a preset threshold value or not; and when the second-order intermodulation low-frequency blocking interference effect index is larger than or equal to a preset threshold value, judging that the second-order intermodulation low-frequency blocking interference exists in the tested frequency equipment.
According to the prediction method for the second-order intermodulation low-frequency blocking effect of the out-of-band electromagnetic radiation, after the second-order intermodulation low-frequency blocking interference effect index corresponding to the out-of-band signal is obtained through calculation, whether the second-order intermodulation low-frequency blocking interference exists in the frequency equipment is judged through comparison with the preset threshold value, the situation that the second-order intermodulation interference is ignored in the prior art is changed, and the communication safety and reliability of the frequency equipment are comprehensively evaluated.
According to a second aspect, an embodiment of the present invention provides an apparatus, including: a memory and a processor, the memory and the processor being communicatively connected to each other, the memory having stored therein computer instructions, and the processor executing the computer instructions to perform the out-of-band electromagnetic radiation second order intermodulation low frequency blocking effect prediction method according to the first aspect or any one of the embodiments of the first aspect.
According to a third aspect, an embodiment of the present invention provides a computer-readable storage medium storing computer instructions for causing a computer to execute the method for predicting the out-of-band electromagnetic radiation second-order intermodulation low-frequency blocking effect described in the first aspect or any one of the embodiments of the first aspect.
Drawings
The features and advantages of the present invention will be more clearly understood by reference to the accompanying drawings, which are illustrative and not to be construed as limiting the invention in any way, and in which:
fig. 1 is a flowchart illustrating a specific example of a method for predicting the second-order intermodulation low-frequency blocking effect of out-of-band electromagnetic radiation according to an embodiment of the present invention;
fig. 2 is a flowchart illustrating another specific example of a method for predicting the out-of-band electromagnetic radiation second-order intermodulation low-frequency blocking effect according to an embodiment of the present invention;
fig. 3 shows a plot of the relative values of the low-frequency interference levels as a function of the intermodulation frequency differences;
FIG. 4 is a graph showing a second order intermodulation low frequency blocking interference factor as a function of radiated frequency offset;
fig. 5 is a schematic structural diagram illustrating a specific example of an out-of-band electromagnetic radiation second-order intermodulation low-frequency blocking effect prediction apparatus provided by an embodiment of the present invention;
fig. 6 shows a schematic structural diagram illustrating a specific example of the apparatus provided by the embodiment of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
In a common communication system, it is generally considered that the frequency of an interference signal of second-order intermodulation interference deviates too far from the operating frequency of a tested device and is often ignored. However, the out-of-band dual-band jamming interference effect test of the communication station finds that: when the frequency difference of the out-of-band electromagnetic radiation interference signal is not large, and the second-order and third-order intermodulation frequencies are far away from the working frequency of the tested equipment, the tested communication radio station is still more sensitive to out-of-band double-frequency electromagnetic radiation than single-frequency electromagnetic radiation, the critical interference field intensity is even different by tens of dB, the phenomenon can not be interpreted by using the effective value and amplitude of the tested radio station to the multi-frequency electromagnetic radiation interference field intensity, or the third-order intermodulation interference mechanism, and the specific test data are shown in table 1.
Table 1 shows the test results of the out-of-band dual-frequency critical interference field strength of a certain communication radio station with 60MHz operating frequency. In order to reflect the difference of critical interference field intensity of dual-frequency electromagnetic radiation and single-frequency electromagnetic radiation, the dual-frequency critical interference field intensity is combined by using a dual-frequency critical interference field intensity EiCritical interference field intensity E with respective single frequencyi0Ratio of (i.e. E)1/E10、E2/E20) Indicating, for frequency combinations, frequency deviations (interference frequencies f) of electromagnetic radiationiOperating frequency f of communication station to be tested0Difference Δ fi＝fi-f0) And (4) showing.
TABLE 1 out-of-band dual-frequency critical interference field strength test result of communication radio station
Whether the tested frequency equipment is sensitive to the effective value of the interference field intensity of the multi-frequency electromagnetic radiation or the amplitude value of the interference field intensity of the multi-frequency electromagnetic radiation, in order to ensure that the dual-frequency electromagnetic radiation does not generate intermodulation effect, the ratio of the interference field intensity of one frequency to the single-frequency critical interference field intensity of the dual-frequency electromagnetic radiation is not less than-6 dB, namely E1/E10Or E2/E20It is not less than-6 dB, and it is clear that the test results in Table 1 do not satisfy the condition, indicating that the nonlinear effect is generated during the test. If the experimental data in table 1 are explained using a third order intermodulation interference mechanism, it is required that the intermodulation new frequency enters into the operating frequency band of the frequency equipment to be tested. Suppose that the operating band of the communication station under test is about f0-30kHz～f0+30kHz, the third order intermodulation frequencies generated by any of the frequency combinations in table 1 cannot enter the operating band of the communication station under test. Even if the working signal of the tested electric table participates in the nonlinear effect, f0The third-order intermodulation frequency generated by the +/-30 kHz working signal and any frequency combination in the table 1 can not enter the working frequency of the communication radio station to be testedIn-band. It can be seen that the out-of-band dual-frequency critical interference field strength test results in table 1 cannot be explained by the third-order intermodulation mechanism.
Through the analysis, the method for neglecting the second-order intermodulation interference in the common communication system has limitation.
A frequency utilization device, such as a communication station, comprises the following communication processes: the radio frequency signal received by the antenna is mixed with a local oscillator after being amplified in one stage, and the working frequency of the radio station is set to be f0Frequency conversion to constant value FmAnd Fm+2f0Of the signal having a center frequency of FmAfter the frequency of the crystal band-pass filter with the bandwidth of 70kHz is selected, the radio-frequency signal received by the antenna can be up-converted and translated to F from the set working frequency of the radio stationmNearby. The radio frequency signal passing through the crystal band-pass filter is further amplified, mixed with a second local oscillator and subjected to low-pass filtering, and the working frequency of the radio station is down-converted and translated to FLAfter variable gain amplification and detection, communication voice or digital information is detected to realize communication. Because the pass band width of the crystal band-pass filter is only about 70kHz, electromagnetic signals with large radiation frequency deviation are difficult to effectively pass through, but out-of-band signals with small radiation frequency deviation can pass through the crystal band-pass filter after frequency selection and attenuation, and enter a down-conversion circuit after further amplification. If out-of-band signal fa、fbThe frequency difference between the frequency difference and the working frequency of the tested frequency equipment is not large, due to the nonlinearity of the mixing circuit, the out-of-band electromagnetic radiation interference signal generates second-order intermodulation in the mixing circuit, and the signal can directly suppress a useful signal after passing through the low-pass filter to form second-order intermodulation low-frequency blocking interference.
In view of the above, an embodiment of the present invention provides a method for predicting a second-order intermodulation low-frequency blocking effect of out-of-band electromagnetic radiation, as shown in fig. 1, the method may include the following steps:
step S101: acquiring the electromagnetic radiation sensitive bandwidth of the tested frequency equipment and at least four out-of-band basic frequency points outside the electromagnetic radiation sensitive bandwidth. In one embodiment, four test frequency points f are selected at equal intervals1To f4As out-of-band fundamental frequency points. Setting the radiation frequency f1>f0(f0Representing the working frequency of the frequency equipment to be tested) and is out of the sensitive frequency band of the frequency equipment to be tested, the interval of the test frequency points is omega, and the radiation frequency offsets corresponding to the four test frequency points are respectively delta f1＝f1-f0、Δf2＝Δf1+Ω、Δf3＝Δf1+2 Ω and Δ f4＝Δf1+3Ω。
Step S102: and performing a second-order intermodulation low-frequency blocking critical interference effect test according to at least four out-of-band basic frequency points, and determining the relation between the relative value of the low-frequency interference level and the intermodulation frequency difference and the relation between a second-order intermodulation low-frequency blocking interference factor and the radiation frequency offset according to the test result. In a specific embodiment, the four test frequency points f selected at equal intervals in step S101 are selected1To f4The two combinations are combined to carry out a second-order intermodulation low-frequency blocking critical interference effect test, and the combination of the radiation field intensity corresponding to the combination of the ith and the j frequency point and the ratio of the single-frequency critical blocking interference field intensity is respectively determined
Is provided with
The formula (1) and the formula (2) are obtained in a simultaneous manner:
the formula (2) and the formula (3) are obtained in a simultaneous manner:
equations (7) and (4), and equations (8) and (5) are solved simultaneously, respectively, and the following can be obtained:
the formula (1) can be substituted with the formulae (9) and (10):
the formula (6) can be substituted with the formulae (9) and (12):
through the calculation, the second-order intermodulation low-frequency blocking interference factor beta corresponding to the four basic frequency offsets can be obtainedi＝β(fi-f0) Relative value L to low frequency interference levelr(2 Ω) and the relative value L of the low frequency interference levelr(Ω)、Lr(3. omega.) and Lr(2. omega.) relationship.
After the second-order intermodulation low-frequency blocking interference factors corresponding to the four basic frequency offsets and the low-frequency interference level relative value relationship corresponding to the three test frequency point intervals are determined, the variation relationship of the low-frequency interference level relative value along with the second-order intermodulation frequency difference can be gradually determined by a recursion test method. In one embodiment, as shown in fig. 2, the relationship between the relative value of the low-frequency interference level and the intermodulation frequency difference can be determined by the following substeps:
step S1021: and acquiring an extrapolation frequency point, performing a second-order intermodulation low-frequency blocking critical interference effect test according to the extrapolation frequency point and any one of at least four out-of-band basic frequency points, and acquiring a ratio of the radiation field intensity corresponding to the extrapolation frequency point to the single-frequency critical blocking interference field intensity according to a test result. During recursion test, selecting an extrapolation frequency point f3n+4＝f1+3(n +1) Ω, n is a natural number, then Δ f3n+4＝Δf1+3(n +1) Ω. Order extrapolation frequency point f3n+4Respectively corresponding to four basic frequency points f1～f4The combination is subjected to a second-order intermodulation low-frequency blocking critical interference effect test, and the combination of the radiation field intensity corresponding to the ith (3n +4) th frequency point combination and the ratio of the single-frequency critical blocking interference field intensity is respectively determined
Step S1022: and calculating a second-order intermodulation low-frequency blocking interference factor corresponding to the extrapolated frequency point according to the ratio of the radiation field intensity corresponding to the extrapolated frequency point to the single-frequency critical blocking interference field intensity. In a specific embodiment, the second-order intermodulation low-frequency blocking interference factor corresponding to the extrapolated frequency point can be calculated by the following formula:
wherein, β (Δ f)3n+4) Indicating an extrapolated frequency point f3n+4A corresponding second order intermodulation low frequency blocking interference factor; Δ f3n+4Indicating an extrapolated frequency point f3n+4Corresponding deviation of radiation frequency, f3n+4＝f1+3(n +1) omega, n being a natural number, omega representing the spacing of said at least four out-of-band fundamental frequency points, f1Representing a first out-of-band basic frequency point of the at least four out-of-band basic frequency points; l isr(3n Ω) represents a relative value of the low-frequency interference level corresponding to the intermodulation frequency difference of 3n Ω; beta (. DELTA.f)4) Representing a radiation frequency deviation Δ f4Corresponding second order intermodulation low frequency blocking interference factor, radiation frequency deviation delta f4Representing a fourth out-of-band fundamental frequency point f of the at least four out-of-band fundamental frequency points4The radiation frequency offset of (1);
indicating out-of-band fundamental frequency point f4Sum extrapolated frequency point f3n+4And carrying out a second-order intermodulation low-frequency blocking critical interference effect test to obtain a ratio of the radiation field intensity to the single-frequency critical blocking interference field intensity.
Step S1023: and calculating low-frequency interference level relative values corresponding to different intermodulation frequency differences according to the second-order intermodulation low-frequency blocking interference factors corresponding to the extrapolated frequency points. In one embodiment, the relative values of the low-frequency interference levels corresponding to different intermodulation frequency differences may be calculated by the following formula:
wherein L isr(3n Ω + Ω) represents a relative value of low-frequency interference levels corresponding to the intermodulation frequency difference (3n Ω + Ω), and Lr(3n Ω + Ω) represents a relative value of low-frequency interference levels corresponding to the intermodulation frequency difference (3n Ω + Ω), and Lr(3n Ω +2 Ω) represents a relative value of low-frequency interference levels corresponding to the intermodulation frequency difference (3n Ω +2 Ω), and Lr(3n Ω +3 Ω) represents a relative value of the low-frequency interference level corresponding to the intermodulation frequency difference (3n Ω +3 Ω); beta (. DELTA.f)1) Representing a radiation frequency deviation Δ f1Corresponding second order intermodulation low frequency blocking interference factor, beta (Δ f)2) Representing a radiation frequency deviation Δ f2Corresponding second order intermodulation low frequency blocking interference factor, beta (Δ f)3) Representing a radiation frequency deviation Δ f3Corresponding second order intermodulation low frequency blocking interference factor, beta (Δ f)3n+4) Indicating an extrapolated frequency point f3n+4Corresponding second order intermodulation low frequency blocking interference factor.
By updating the extrapolated frequency point and repeatedly executing steps S1021 to S1023, the relative values of the low-frequency interference levels corresponding to other intermodulation frequency differences can be calculated.
Step S1024: and drawing a fitting curve of the low-frequency interference level relative values according to the low-frequency interference level relative values corresponding to different intermodulation frequency differences. Figure 3 is a graph showing the relative values of the glitch level.
In order to determine the relationship between the second-order intermodulation low-frequency blocking interference factor and the radiation frequency offset, in a specific embodiment, as shown in fig. 2, after determining the relationship between the relative value of the low-frequency interference level and the intermodulation frequency difference, the following sub-steps may be added:
step S1025: and acquiring at least four other out-of-band basic frequency points outside the electromagnetic radiation sensitive bandwidth. In one embodiment, the four test frequency points f selected above are excluded1To f4Besides, four out-of-band basic frequency points f can be selected1' to f4'，f1' to f4The frequency intervals of' are the same.
Step S1026: performing a second-order intermodulation low-frequency blocking critical interference effect test according to at least four other out-of-band basic frequency points, and performing a low-frequency interference test according to the test result and the low-frequency interference corresponding to different intermodulation frequency differencesAnd calculating the relative value of the interference level, and calculating second-order intermodulation low-frequency blocking interference factors corresponding to the other at least four out-of-band basic frequency points. Let newly selected four out-of-band basic frequency points f1' to f4The two combinations are combined to perform a second-order intermodulation low-frequency blocking critical interference effect test, and then second-order intermodulation low-frequency blocking interference factors corresponding to different frequency offsets can be calculated according to the formulas (9) to (12). In the calculation process, L can be determined by using the curve plotted in step S1024rThe value of (2 Ω).
By updating the out-of-band fundamental frequency point and repeatedly executing the steps from S1025 to S1026, the second-order intermodulation low-frequency blocking interference factor corresponding to other radiation frequency offset can be calculated.
Step S1027: and drawing a fitting curve of the second-order intermodulation low-frequency blocking interference factors according to the second-order intermodulation low-frequency blocking interference factors corresponding to the other at least four out-of-band basic frequency points. Fig. 4 is a graph showing a second order intermodulation low frequency blocking interference factor.
Step S103: and establishing a second-order intermodulation low-frequency blocking interference effect model according to the low-frequency interference level relative value and the second-order intermodulation low-frequency blocking interference factor, and predicting whether the second-order intermodulation low-frequency blocking interference exists in the tested frequency equipment according to the model. In one embodiment, the second order intermodulation low frequency blocking interference effect model may be established by the following equation:
wherein R is2(fb-fa) Representing a frequency faAnd fbThe second-order intermodulation low-frequency blocking interference effect index corresponding to the out-of-band signal; beta (f)a-f0) Representing a frequency faThe second-order intermodulation low-frequency blocking interference factor corresponding to the out-of-band signal of (f)a-f0) Representing a frequency faRelative to the operating frequency f of the frequency device under test0The radiation frequency offset of (1); beta (f)b-f0) Representing a frequency fbThe second-order intermodulation low-frequency blocking interference factor corresponding to the out-of-band signal of (f)b-f0) Representing a frequency fbRelative to the operating frequency f of the frequency device under test0The radiation frequency offset of (1); l isr(fb-fa) Representing a frequency faAnd fbRelative value of the low-frequency interference level corresponding to the out-of-band signal of (f)b-fa) Representing a frequency faAnd fbInter-modulation frequency difference between the out-of-band signals of (1);
representing a frequency faThe ratio of the radiation field intensity corresponding to the out-of-band signal to the single-frequency critical blocking interference field intensity;
representing a frequency fbThe ratio of the radiation field intensity corresponding to the out-of-band signal to the critical blocking interference field intensity of the single frequency.
Optionally, after calculating the second-order intermodulation low-frequency blocking interference effect index corresponding to the out-of-band signal, as shown in fig. 2, the following steps may be added to predict whether the second-order intermodulation interference occurs to the frequency device under test:
step S104: and judging whether the second-order intermodulation low-frequency blocking interference effect index is greater than or equal to a preset threshold value. In one embodiment, the preset threshold may be set to 1, and when the second-order intermodulation low-frequency blocking interference effect index is greater than or equal to the preset threshold, step S105 is executed; when the second-order intermodulation low-frequency blocking interference effect index is smaller than the preset threshold value, the tested frequency equipment can be considered to be capable of normally working.
Step S105: and judging that the tested frequency equipment has second-order intermodulation low-frequency blocking interference.
According to the prediction method for the second-order intermodulation low-frequency blocking effect of the out-of-band electromagnetic radiation, provided by the embodiment of the invention, the evaluation of the second-order intermodulation interference of the communication equipment is realized by establishing a second-order intermodulation low-frequency blocking interference effect model. Through a test mode, two important parameters in the model, namely a low-frequency interference level relative value and a value of a second-order intermodulation low-frequency blocking interference factor, are determined, quantitative evaluation of second-order intermodulation interference is achieved, and the method is suitable for various frequency devices.
The accuracy of the effect test evaluation depends on the scientificity of the effect evaluation model and the repeatability and accuracy of the model parameter test. In order to verify the accuracy of the second-order intermodulation low-frequency blocking interference effect model and the parameter determination method thereof, firstly, the repeatability of the second-order intermodulation low-frequency blocking interference factor and the relative value of the low-frequency interference level determined by the basic frequency point model parameter test method is checked through a single-frequency and out-of-band dual-frequency electromagnetic radiation low-frequency blocking critical interference effect test of a certain type of ultrashort wave communication radio station.
By adopting the steps S1021 to S1024 in the method embodiment, the repeatability tests of the second-order intermodulation low-frequency blocking critical interference effect test of the initial radiation frequency offset of 150kHz, the test frequency point interval of 10kHz, the initial frequency offset of 127kHz and the test frequency point interval of 25kHz are respectively carried out. According to the test data, the second-order intermodulation low-frequency blocking interference factors beta of four basic frequency points are respectively obtained by using the formulas (9) to (12)i＝β(fi-f0) Relative value L to low frequency interference levelr(20kHz) or Lr(50 kHz); meanwhile, the low frequency interference level relative value L is established by using the formulas (13) to (14)r(10kHz)、Lr(30kHz) and Lr(20kHz) and Lr(25kHz)、Lr(75kHz) and LrThe relationship (50kHz) and the calculation results are shown in Table 2.
Table 2 second order intermodulation model parameter test repeatability of the communication radio station under test
As can be seen from the calculation results of table 2: by adopting the method for determining the basic frequency point model parameters, the second-order intermodulation model parameters of the tested equipment can be accurately determined, and the uncertainty of the test is within 2 dB. The second order intermodulation glitch factor is, in contrast, more accurate than the relative value of the glitch level. In order to reduce the testing error of the basic frequency point model parameters, a plurality of groups of tests can be carried out under the same test frequency point combination, and the testing average value of the corresponding parameters is taken as the testing value of the model parameters.
The radiation frequency deviation corresponding to the initial test frequency point is 210kHz, the interval of the test frequency points is omega which is 10kHz, and the four test frequency points are combined pairwise to carry out second-order intermodulation low-frequency blocking critical interference effect test. In order to reduce the influence of the uncertainty of the basic frequency offset model parameter test on the transmission of other parameter test results, three groups of second-order intermodulation low-frequency blocking critical interference effect tests with the same test frequency point combination are carried out at different communication distances and different dates, the test calculation results are shown in table 3, and the average value of the three groups of calculation results is used as the test value of the basic frequency point model parameter.
TABLE 3 basic frequency point model parameter calculation results
The results of the model parameter calculations in tables 2 and 3 can be seen by comprehensive analysis: under different test conditions, a basic frequency point model parameter test method is adopted for testing, the test error of the second-order intermodulation low-frequency blocking interference factor obtained through calculation can be controlled to be about 2dB, and the test error of the relative value of the low-frequency interference level can be as high as 6 dB.
Based on the four basic frequency point model parameters determined in Table 3, the extrapolation frequency point f is selected3n+4＝f1+30(n +1) kHz, where n is a natural number, then Δ f3n+4＝Δf1+30(n+1)kHz。f3n+4The second-order intermodulation low-frequency blocking critical interference effect test is performed by combining with the four basic frequency points, and the specific process can refer to the steps S1021 to S1023 in the above method embodiment. Because the frequency offset of the third-order intermodulation of the frequency point combination with the frequency offsets of 210kHz and 390kHz respectively is 30kHz, the frequency offset falls into the sensitive frequency band of the communication radio station to be tested, and in order to avoid the influence of the third-order intermodulation on the test result, the data is deleted and the extrapolation is stopped.
According to the test data and the basic frequency point model parameter test values in Table 3, the extrapolation frequency point f is firstly calculated and determined by using the formula (15)3n+4Corresponding second order intermodulation low frequency blocking interference factor beta (Δ f)3n+4) Then use formula(16) Equation (18) calculates the low-frequency interference level relative values corresponding to different intermodulation frequency differences in sequence, the calculation result is shown in table 4 (including basic frequency point data), and accordingly, a change relation curve of the low-frequency interference level relative value of the communication station to be tested along with the intermodulation frequency differences is made, as shown in fig. 3, a test data point and a fitting curve made according to the maximum error of about 2dB are given in the graph.
TABLE 4 calculation of the relative values of the low-frequency interference levels of the communication stations under test
According to the variation relation curve of the low-frequency interference level relative value of the tested communication radio station along with the intermodulation frequency difference, taking Lr(Δ f) minimum value of 0dB, determine LrThe final values of (Δ f) are shown in Table 5, Lr(20kHz)＝11dB。
TABLE 5 Low-frequency interference level of communication station under test
Because the low-frequency interference level is a key technical index for determining whether the second-order intermodulation low-frequency blocking interference can occur to the tested radio station, the influence of the second-order intermodulation low-frequency blocking interference on the tested communication radio station can not be considered after the interference level is improved by 20 dB. According to the variation relation of the low-frequency interference level of the tested communication radio station along with the intermodulation frequency difference, the sensitive intermodulation frequency difference of the tested communication radio station with second-order intermodulation low-frequency blocking interference can be considered as (10-135) kHz.
Mixing L withr(20kHz)＝11.0dB、LrThe (50kHz) 1.5dB is substituted into tables 2 and 3, respectively, to obtain the second-order intermodulation low-frequency blocking interference factor corresponding to the fundamental frequency point radiation frequency offset, as shown in table 6.
TABLE 6 calculation results of fundamental frequency point second-order intermodulation low-frequency blocking interference factors of communication radio station
In order to determine the change rule of the second-order intermodulation low-frequency blocking interference factor along with the radiation frequency offset, on the basis of the test, four frequency points are selected according to a determination method of basic frequency point model parameters, the third-order intermodulation frequency of the test frequency combination is ensured to be outside the sensitive frequency band of the tested communication radio station, and the second-order intermodulation low-frequency blocking critical interference effect test is carried out by pairwise combination. Therefore, radiation frequency offsets corresponding to initial test frequency points are respectively set to be 75kHz, 280kHz, 410kHz, 560kHz, 710kHz and 840kHz, equal frequency intervals omega of the corresponding test frequency points are respectively set to be 12kHz, 30kHz and 20kHz, and frequency differences are measured for pairwise combined out-of-band dual-frequency second-order intermodulation critical low-frequency blocking interference field intensity of 2 omega. Based on the relative values of the low-frequency interference levels of the communication stations under test in Table 5, L is interpolated with reference to FIG. 2r(24kHz)＝3dB、Lr(60kHz)＝0dB、LrBased on the test data, the calculation is performed by using equations (9) to (12) to obtain second-order intermodulation low-frequency blocking interference factors corresponding to different radiation frequency offsets, respectively, and the calculation results are shown in table 7.
TABLE 7 second-order intermodulation low-frequency blocking interference factor calculation results of communication radio station
The test data is not enough to determine the low frequency offset change rule of the second-order intermodulation low-frequency blocking interference factor of the communication radio station to be tested, and when the frequency offset is less than 75kHz, four frequency points are difficult to select at equal intervals according to the determination method of the basic frequency point model parameters, so that the three-order intermodulation frequency of the two-by-two combination of the four frequency points effectively avoids the sensitive frequency of the communication radio station to be tested. In order to determine a second-order intermodulation low-frequency blocking interference factor corresponding to lower frequency offset, through a second-order intermodulation low-frequency blocking critical interference effect test, the combination of radiation field intensity corresponding to frequency point combinations with frequency offsets of 55kHz and 75kHz and the ratio of single-frequency critical blocking interference field intensity of the radiation field intensity is determined to be (-4.4dB, -4.1dB), and L is selectedr(20kHz) ═ 11.0dB, beta (75kHz) ═ 20.0dB, according toThe following equation gives β (55kHz) — 0.5 dB.
Wherein, β (f)2-f0)＝β(75kHz)＝20.0dB，Lr(f2-f1)＝Lr(20kHz)＝11.0dB，
The combination of the radiation field intensity corresponding to the frequency point combination with the frequency deviation of 55kHz and 75kHz and the ratio of the single-frequency critical blocking interference field intensity is (-4.4dB, -4.1 dB).
The test calculation results of table 6, table 7 and beta (55kHz) are integrated to obtain the change rule of the second-order intermodulation low-frequency blocking interference factor of the communication station to be tested along with the radiation frequency offset, as shown in fig. 4, the test data points and the fitting curve thereof given in the figure can control the fitting error within 3dB except for the individual data points with larger frequency offset, and can meet the requirement of effect evaluation.
As can be seen from FIG. 4, the second-order intermodulation low-frequency blocking interference is not easily generated when the radiation frequency is too large or too small, and the second-order intermodulation low-frequency blocking interference cannot be ignored when the radiation frequency deviation of the communication radio station under test is within the range of (65-880) kHz.
The embodiment of the invention also provides a device for predicting the second-order intermodulation low-frequency blocking effect of out-of-band electromagnetic radiation, which can comprise a test frequency point unit 501, a parameter calculation unit 502 and a modeling unit 503, as shown in fig. 5.
The test frequency point unit 501 is configured to obtain an electromagnetic radiation sensitive bandwidth of a device to be tested and at least four out-of-band basic frequency points outside the electromagnetic radiation sensitive bandwidth; the specific working process of the method can be referred to as step S101 in the above method embodiment.
The parameter calculation unit 502 is configured to perform a second-order intermodulation low-frequency blocking critical interference effect test according to at least four out-of-band fundamental frequency points, and determine a relationship between a relative value of a low-frequency interference level and an intermodulation frequency difference and a relationship between a second-order intermodulation low-frequency blocking interference factor and a radiation frequency offset according to a test result; the specific working process of the method can be referred to as step S102 in the above method embodiment.
The modeling unit 503 is configured to establish a second-order intermodulation low-frequency blocking interference effect model according to the low-frequency interference level relative value and the second-order intermodulation low-frequency blocking interference factor, and predict whether the tested radio frequency equipment has second-order intermodulation low-frequency blocking interference according to the model; the specific working process of the method can be referred to as step S103 in the above method embodiment.
Optionally, the determining unit 504 may be further added in the out-of-band electromagnetic radiation second-order intermodulation low-frequency blocking effect predicting device, so as to predict whether the second-order intermodulation interference will occur in the tested frequency device according to the calculated second-order intermodulation low-frequency blocking interference effect index, and the specific working process of the predicting device may be described in steps S104 to S105 in the above method embodiment.
An apparatus according to an embodiment of the present invention is further provided, and as shown in fig. 6, the apparatus may include a processor 601 and a memory 602, where the processor 601 and the memory 602 may be connected by a bus or in another manner, and fig. 6 illustrates an example of a connection by a bus.
The memory 602, serving as a non-transitory computer-readable storage medium, may be used to store non-transitory software programs, non-transitory computer-executable programs, and modules, such as program instructions/modules corresponding to the out-of-band electromagnetic radiation second-order intermodulation low-frequency blocking effect prediction method in the embodiment of the present invention (for example, the experimental frequency point unit 501, the parameter calculation unit 502, and the modeling unit 503 shown in fig. 5). The processor 601 executes the non-transitory software programs, instructions and modules stored in the memory 602 to execute various functional applications and data processing of the processor, that is, to implement the out-of-band electromagnetic radiation second-order intermodulation low-frequency blocking effect prediction method in the above method embodiment.
The memory 602 may include a storage program area and a storage data area, wherein the storage program area may store an operating system, an application program required for at least one function; the storage data area may store data created by the processor 601, and the like. Further, the memory 602 may include high speed random access memory, and may also include non-transitory memory, such as at least one magnetic disk storage device, flash memory device, or other non-transitory solid state storage device. In some embodiments, the memory 602 may optionally include memory located remotely from the processor 601, which may be connected to the processor 601 through a network. Examples of such networks include, but are not limited to, the internet, intranets, local area networks, mobile communication networks, and combinations thereof.
The one or more modules are stored in the memory 602 and when executed by the processor 601 perform the out-of-band electromagnetic radiation second order intermodulation low frequency blocking effect prediction method as in the embodiments of figures 1-2.
The details of the above-mentioned device can be understood by referring to the corresponding descriptions and effects in the embodiments shown in fig. 1 to fig. 2, and are not described herein again.
It will be understood by those skilled in the art that all or part of the processes of the methods of the embodiments described above can be implemented by a computer program, which can be stored in a computer-readable storage medium, and when executed, can include the processes of the embodiments of the methods described above. The storage medium may be a magnetic Disk, an optical Disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a Flash Memory (Flash Memory), a Hard Disk (Hard Disk Drive, abbreviated as HDD), a Solid State Drive (SSD), or the like; the storage medium may also comprise a combination of memories of the kind described above.
Although the embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the invention, and such modifications and variations fall within the scope defined by the appended claims.
Claims (5)
1. A second-order intermodulation low-frequency blocking effect prediction method for out-of-band electromagnetic radiation is characterized by comprising the following steps:
acquiring an electromagnetic radiation sensitive bandwidth of a tested frequency device and at least four out-of-band basic frequency points outside the electromagnetic radiation sensitive bandwidth;
performing a second-order intermodulation low-frequency blocking critical interference effect test according to the at least four out-of-band basic frequency points, and determining a relation between a low-frequency interference level relative value and an intermodulation frequency difference and a relation between a second-order intermodulation low-frequency blocking interference factor and a radiation frequency offset according to a test result, wherein the method comprises the following steps:
acquiring an extrapolation frequency point, performing a second-order intermodulation low-frequency blocking critical interference effect test according to the extrapolation frequency point and any one of the at least four out-of-band basic frequency points, and acquiring a ratio of a radiation field intensity corresponding to the extrapolation frequency point to a single-frequency critical blocking interference field intensity according to a test result;
calculating a second-order intermodulation low-frequency blocking interference factor corresponding to the extrapolated frequency point according to the ratio of the radiation field intensity corresponding to the extrapolated frequency point to the single-frequency critical blocking interference field intensity, wherein the calculation comprises the following steps: by passing
Calculating a second-order intermodulation low-frequency blocking interference factor corresponding to the extrapolated frequency point, wherein beta (delta f)3n+4) Indicating an extrapolated frequency point f3n+4A corresponding second order intermodulation low frequency blocking interference factor; Δ f3n+4Indicating an extrapolated frequency point f3n+4Corresponding deviation of radiation frequency, f3n+4＝f1+3(n +1) omega, n being a natural number, omega representing the spacing of said at least four out-of-band fundamental frequency points, f1Representing the at least four out-of-band fundamental frequency pointsThe first out-of-band fundamental frequency point in; l isr(3n Ω) represents a relative value of the low-frequency interference level corresponding to the intermodulation frequency difference of 3n Ω; beta (. DELTA.f)4) Representing a radiation frequency deviation Δ f4Corresponding second order intermodulation low frequency blocking interference factor, radiation frequency deviation delta f4Representing a fourth out-of-band fundamental frequency point f of the at least four out-of-band fundamental frequency points4The radiation frequency offset of (1);
indicating out-of-band fundamental frequency point f4Sum extrapolated frequency point f3n+4Carrying out a second-order intermodulation low-frequency blocking critical interference effect test to obtain a ratio of radiation field intensity to single-frequency critical blocking interference field intensity;
calculating low-frequency interference level relative values corresponding to different intermodulation frequency differences according to the second-order intermodulation low-frequency blocking interference factors corresponding to the extrapolated frequency points, wherein the calculation comprises the following steps: by passing
Calculating the low-frequency interference level relative value corresponding to the different intermodulation frequency differences, wherein Lr(3n Ω + Ω) represents a relative value of low-frequency interference levels corresponding to the intermodulation frequency difference (3n Ω + Ω), and Lr(3n Ω +2 Ω) represents a relative value of low-frequency interference levels corresponding to the intermodulation frequency difference (3n Ω +2 Ω), and Lr(3n Ω +3 Ω) represents a relative value of the low-frequency interference level corresponding to the intermodulation frequency difference (3n Ω +3 Ω); beta (. DELTA.f)1) Representing a radiation frequency deviation Δ f1Corresponding second order intermodulation low frequency blocking interference factor, beta (Δ f)2) Representing a radiation frequency deviation Δ f2Corresponding second order intermodulation low frequencyBlocking interference factor, beta (Δ f)3) Representing a radiation frequency deviation Δ f3Corresponding second order intermodulation low frequency blocking interference factor, beta (Δ f)3n+4) Indicating an extrapolated frequency point f3n+4A corresponding second order intermodulation low frequency blocking interference factor;
indicating out-of-band fundamental frequency point f3Sum extrapolated frequency point f3n+4Carrying out a second-order intermodulation low-frequency blocking critical interference effect test to obtain a ratio of radiation field intensity to single-frequency critical blocking interference field intensity;
indicating out-of-band fundamental frequency point f2Sum extrapolated frequency point f3n+4Carrying out a second-order intermodulation low-frequency blocking critical interference effect test to obtain a ratio of radiation field intensity to single-frequency critical blocking interference field intensity;
indicating out-of-band fundamental frequency point f1Sum extrapolated frequency point f3n+4Carrying out a second-order intermodulation low-frequency blocking critical interference effect test to obtain a ratio of radiation field intensity to single-frequency critical blocking interference field intensity;
drawing a fitting curve of the low-frequency interference level relative value according to the low-frequency interference level relative value corresponding to the different intermodulation frequency differences;
acquiring at least four other out-of-band basic frequency points outside the electromagnetic radiation sensitive bandwidth; performing a second-order intermodulation low-frequency blocking critical interference effect test according to the at least four other out-of-band fundamental frequency points, and calculating second-order intermodulation low-frequency blocking interference factors corresponding to the at least four other out-of-band fundamental frequency points according to a test result and low-frequency interference level relative values corresponding to the different intermodulation frequency differences, including: by passing
Calculating second-order intermodulation low-frequency blocking interference factors corresponding to the other at least four out-of-band basic frequency points, wherein beta (delta f'1) Represents an out-of-band fundamental frequency point delta f'1Corresponding second order intermodulation low frequency blocking interference factor, beta (Δ f'2) Represents an out-of-band fundamental frequency point delta f'2Corresponding second order intermodulation low frequency blocking interference factor, beta (Δ f'3) Represents an out-of-band fundamental frequency point delta f'3Corresponding second order intermodulation low frequency blocking interference factor, beta (Δ f'4) Represents an out-of-band fundamental frequency point delta f'4A corresponding second order intermodulation low frequency blocking interference factor; l isr(2 Ω) represents a relative value of the low-frequency interference level corresponding to the intermodulation frequency difference (2 Ω);
represents out-of-band basic frequency point f'iAnd f'jCarrying out a second-order intermodulation low-frequency blocking critical interference effect test to obtain a ratio of radiation field intensity to single-frequency critical blocking interference field intensity;
drawing a fitting curve of the second-order intermodulation low-frequency blocking interference factors according to the second-order intermodulation low-frequency blocking interference factors corresponding to the at least four other out-of-band basic frequency points;
and establishing a second-order intermodulation low-frequency blocking interference effect model according to the low-frequency interference level relative value and the second-order intermodulation low-frequency blocking interference factor, and predicting whether the tested frequency equipment has second-order intermodulation low-frequency blocking interference according to the model.
2. The method for predicting the out-of-band electromagnetic radiation second order intermodulation low frequency blocking effect according to claim 1, wherein the second order intermodulation low frequency blocking interference effect model is:
wherein R is2(fb-fa) Representing a frequency faAnd fbThe second-order intermodulation low-frequency blocking interference effect index corresponding to the out-of-band signal; beta (f)a-f0) Representing a frequency faThe second-order intermodulation low-frequency blocking interference factor corresponding to the out-of-band signal of (f)a-f0) Representing a frequency faRelative to the operating frequency f of the frequency device under test0The radiation frequency offset of (1); beta (f)b-f0) Representing a frequency fbThe second-order intermodulation low-frequency blocking interference factor corresponding to the out-of-band signal of (f)b-f0) Representing a frequency fbRelative to the operating frequency f of the frequency device under test0The radiation frequency offset of (1); l isr(fb-fa) Representing a frequency faAnd fbRelative value of the low-frequency interference level corresponding to the out-of-band signal of (f)b-fa) Representing a frequency faAnd fbInter-modulation frequency difference between the out-of-band signals of (1);
representing a frequency faThe ratio of the radiation field intensity corresponding to the out-of-band signal to the single-frequency critical blocking interference field intensity;
representing a frequency fbThe ratio of the radiation field intensity corresponding to the out-of-band signal to the critical blocking interference field intensity of the single frequency.
3. The out-of-band electromagnetic radiation second order intermodulation glitch prediction method of claim 2 further comprising, after the modeling second order intermodulation glitch from the relative magnitudes of the glitch levels and the second order intermodulation glitch factors, the out-of-band electromagnetic radiation second order intermodulation glitch prediction method further comprising:
judging whether the second-order intermodulation low-frequency blocking interference effect index is larger than or equal to a preset threshold value or not;
and when the second-order intermodulation low-frequency blocking interference effect index is larger than or equal to a preset threshold value, judging that the second-order intermodulation low-frequency blocking interference exists in the tested frequency equipment.
4. An apparatus, comprising:
a memory and a processor, the memory and the processor being communicatively coupled to each other, the memory having stored therein computer instructions, the processor being configured to execute the method of predicting out-of-band electromagnetic radiation second order intermodulation low frequency blocking effects as claimed in any one of claims 1 to 3 by executing the computer instructions.
5. A computer-readable storage medium having stored thereon computer instructions for causing a computer to execute the out-of-band electromagnetic radiation second order intermodulation low frequency blocking effect prediction method of any one of claims 1 to 3.
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Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101425857A (en) * | 2008-11-20 | 2009-05-06 | 北京航空航天大学 | Diagnosis method for non-linear interference outside communication band of transmission device |
| US8620220B2 (en) * | 2009-03-31 | 2013-12-31 | Broadcom Corporation | Method and system for mitigating interference between a plurality of femtocells utilizing transmission deferral |
| CN108445313A (en) * | 2018-01-31 | 2018-08-24 | 中国人民解放军陆军工程大学 | With frequency equipment electromagnetic radiation effect Comprehensive Prediction Method and terminal device |
| CN108490281A (en) * | 2018-01-31 | 2018-09-04 | 中国人民解放军陆军工程大学 | With frequency equipment random noise electromagnetic radiation effect prediction technique and terminal device |
| CN108490280A (en) * | 2018-01-31 | 2018-09-04 | 中国人民解放军陆军工程大学 | With frequency equipment with interior multifrequency electromagnetic radiation effect prediction technique and terminal device |
| CN108833039A (en) * | 2018-06-13 | 2018-11-16 | 中国人民解放军陆军工程大学 | Block interference predicting method and terminal device with outer electromagnetic radiation third order intermodulation |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE29914606U1 (en) * | 1999-08-20 | 2000-12-28 | Diehl Stiftung & Co | Radio reception tester |
| CN106027176B (en) * | 2016-06-29 | 2017-05-24 | 中国人民解放军军械工程学院 | Receiver in-band dual frequency electromagnetic radiation large signal blocking interference effect prediction method |
-
2018
- 2018-12-12 CN CN201811517717.8A patent/CN109547130B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101425857A (en) * | 2008-11-20 | 2009-05-06 | 北京航空航天大学 | Diagnosis method for non-linear interference outside communication band of transmission device |
| US8620220B2 (en) * | 2009-03-31 | 2013-12-31 | Broadcom Corporation | Method and system for mitigating interference between a plurality of femtocells utilizing transmission deferral |
| CN108445313A (en) * | 2018-01-31 | 2018-08-24 | 中国人民解放军陆军工程大学 | With frequency equipment electromagnetic radiation effect Comprehensive Prediction Method and terminal device |
| CN108490281A (en) * | 2018-01-31 | 2018-09-04 | 中国人民解放军陆军工程大学 | With frequency equipment random noise electromagnetic radiation effect prediction technique and terminal device |
| CN108490280A (en) * | 2018-01-31 | 2018-09-04 | 中国人民解放军陆军工程大学 | With frequency equipment with interior multifrequency electromagnetic radiation effect prediction technique and terminal device |
| CN108833039A (en) * | 2018-06-13 | 2018-11-16 | 中国人民解放军陆军工程大学 | Block interference predicting method and terminal device with outer electromagnetic radiation third order intermodulation |
Non-Patent Citations (3)
| Title |
|---|
| Electromagnetic Compatibility Prediction Method Under the Multifrequency in-Band Interference Environment;Wei Li 等;《IEEE TRANSACTIONS ON ELECTROMAGNETIC COMPATIBILITY》;20180430;第520-528页 * |
| Prediction Model for Radiation from Base-Station Antennas Using Electromagnetic Simulation;Chan-Keong Chio;《Proceedings of APMC 2012》;20121231;第1082-1084页 * |
| 接收机带内双频阻塞干扰机理建模与验证;王雅平 等;《北京理工大学学报》;20180731;第710-714页 * |
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