A method for correcting the characteristic loss of harmonic spurious radiation emission of millimeter-wave frequency antennas

Abstract

The present invention relates to a method for correcting characteristic loss of harmonic spurious radiation emission of a millimeter-wave frequency band antenna. The method comprises calculating characteristic loss of a far-field test environment and characteristic loss of an actual working environment of the millimeter-wave frequency band device under dry air and water vapor conditions according to far-field test environment parameters and actual working environment parameters of the millimeter-wave frequency band device; calculating atmospheric characteristic loss values ​​in the far-field test environment and the actual working environment according to the characteristic loss of the millimeter-wave frequency band device in the far-field test environment and the characteristic loss of the actual working environment and a path length; further calculating an atmospheric characteristic loss correction factor for harmonic spurious radiation emission of the millimeter-wave frequency band device antenna according to the calculated atmospheric characteristic loss values ​​in the far-field test environment and the actual working environment; and calculating a correction result of harmonic spurious radiation emission of the millimeter-wave frequency band device antenna according to the correction factor and a harmonic spurious radiation emission result of the millimeter-wave frequency band device antenna obtained by testing the millimeter-wave frequency band device in the far-field test environment.

Description

Technical Field

[0001] The present invention belongs to the field of electromagnetic compatibility testing, specifically to the problem of testing the harmonic spurious radiation emission of millimeter-wave frequency band device antennas, and more particularly to the problem of correcting the influence of characteristic loss of the harmonic spurious radiation emission test of millimeter-wave frequency band device antennas, and more particularly to a method for correcting the characteristic loss of the harmonic spurious radiation emission of millimeter-wave frequency band antennas. Background Art

[0002] Millimeter waves refer to electromagnetic waves with a wavelength of 1 to 10 mm (frequency band of 30 GHz to 300 GHz). Millimeter waves have many advantages, such as wide bandwidth, suitable for various broadband signal processing; narrow beam and good directionality; compared with lasers, the propagation of millimeter waves is much less affected by climate and can be considered to have all-weather characteristics; compared with microwaves, millimeter wave devices and systems are easier to miniaturize. In recent years, with the improvement of semiconductor processing level and equipment operating frequency, millimeter waves are increasingly used in communications, radar, remote sensing and radio astronomy. The number of millimeter wave frequency band devices is also increasing, and the electromagnetic environment of the millimeter wave band is becoming increasingly complex. In order to ensure that each device can interfere with each other, it is increasingly urgent to conduct electromagnetic compatibility testing and evaluation of millimeter wave frequency band devices.

[0003] However, the electromagnetic compatibility (EMC) antenna harmonic and spurious radiation emission testing frequency band of most devices currently only reaches 40 GHz. From a demand perspective, the current highest test frequency range does not meet the EMC testing needs of current and future millimeter-wave frequency band devices. Therefore, there is an urgent need to study EMC test methods for millimeter-wave frequency bands above 40 GHz, especially how to conduct EMC antenna harmonic and spurious radiation emission testing of millimeter-wave frequency band devices under near-ground and far-field conditions.

[0004] A crucial consideration when conducting electromagnetic compatibility (EMC) antenna harmonic and spurious radiated emissions testing for millimeter-wave devices under near-Earth and far-field conditions is that millimeter-wave propagation losses are significant in the atmosphere. Losses are minimal only when propagating through atmospheric window frequencies (frequencies where certain losses due to resonant absorption by gas molecules are minimal). Therefore, transmission losses in the millimeter-wave band include not only path loss but also characteristic loss. Characteristic loss refers to the loss of electromagnetic waves in the millimeter-wave band caused by absorption by atmospheric molecules (such as oxygen and water vapor). This loss can significantly impact the results of antenna harmonic and spurious radiated emissions testing under near-Earth conditions. Factors such as the test altitude, temperature, and relative humidity can have a significant impact. Differences between the test environment and the actual device operating environment can affect test results, and these effects are significant at peak frequencies.

[0005] Therefore, when conducting electromagnetic compatibility (EMC) far-field antenna harmonic spurious radiation emission tests on millimeter-wave frequency band devices under near-Earth far-field conditions, it is necessary to consider the characteristic loss of millimeter waves, that is, the impact of the difference between the test environment and the actual working environment of the equipment (such as near-Earth state / space system, etc.) on the test results. The deviation of the results caused by conducting antenna harmonic spurious radiation emission tests in a non-actual working environment should be quantitatively analyzed and corrected. Summary of the Invention

[0006] The purpose of the present invention is to provide a method for correcting the characteristic loss of harmonic spurious radiation emission of millimeter wave frequency band antennas, which is used to correct the test results after the antenna harmonic spurious radiation emission test of millimeter wave equipment.

[0007] To achieve the above-mentioned purpose, the technical solution adopted by the present invention is as follows.

[0008] The present invention proposes a method for correcting the characteristic loss of harmonic spurious radiation emission of millimeter-wave frequency band antennas, the method comprising:

[0009] Step 1: Calculate the characteristic loss γ of the far-field test environment under dry air conditions based on the far-field test environment parameters and actual working environment parameters of the millimeter wave frequency band device. test_o and the characteristic loss γ of the actual working environment real_o ;

[0010] Step 2: Calculate the characteristic loss γ of the far-field test environment under water vapor conditions based on the far-field test environment parameters and actual working environment parameters of the millimeter wave frequency band device. test_w and the characteristic loss γ of the actual working environment rea l _w ;

[0011] Step 3: γ calculated according to step 1 test_o and γ real_o , γ calculated in step 2 test_w and γ real_w And the path length, further calculate the atmospheric characteristic loss value A of the millimeter wave frequency band far-field test environment test_atm And the atmospheric characteristic loss value A of the actual working environment real_atm ;

[0012] Step 4: Based on the A calculated in step 3 test_atm and A real_atm , calculate the atmospheric characteristic loss correction factor A of the harmonic spurious radiation emission of the millimeter wave band device antenna atm_mod ;

[0013] Step 5: Obtain the antenna harmonic spurious radiation emission of the millimeter wave frequency band device directly tested by the receiver in the far-field test environment. test, and A calculated according to step 4 atm_mod The calculated correction result E of the antenna harmonic spurious radiation emission of the millimeter wave frequency band device is real .

[0014] As one of the improvements to the above technical solution, in step 1, γ test_o and γ real_o γ is calculated by the following o The formula is calculated, where γ is calculated test_o When the temperature and pressure of the far-field test environment are used, γ is calculated. real_o When using the actual working environment temperature and pressure;

[0015] For f≤54GHz, γ o The calculation formula is:

[0016]

[0017] Among them, the variable r t =288 / (273+t), t is temperature; f is millimeter wave frequency; variable r p =p / 1013, where p is the pressure; the variables ξ1, ξ2, and ξ3 are:

[0018]

[0019]

[0020]

[0021] function express: a, b, c, d represent variables respectively:

[0022] For 54GHz<f≤60GHz, γ o The calculation formula is:

[0023]

[0024] Among them, the variable γ 54 , γ 58 , γ 60 They are:

[0025]

[0026]

[0027]

[0028] For 60GHz<f≤62GHz, γ o The calculation formula is:

[0029]

[0030] Among them, the variable

[0031] For 62GHz<f≤66GHz, γ o The calculation formula is:

[0032]

[0033] Among them, the variable γ 64 and γ 66 They are:

[0034]

[0035]

[0036] For 66GHz<f≤120GHz, γ o The calculation formula is:

[0037]

[0038] Among them, variables ξ4, ξ5, ξ6 and ξ7 are:

[0039]

[0040]

[0041]

[0042]

[0043] For 120GHz<f≤350GHz, γ o The calculation formula is:

[0044]

[0045] Among them, the variable

[0046] As one of the improvements to the above technical solution, in step 2, γ test_w and γ real_w γ is calculated by the following w The formula is calculated, where γ is calculated test_w When , use the temperature and water vapor density of the far-field test environment; calculate γ real_w When using the actual working environment temperature and water vapor density;

[0047]

[0048] Where f is the millimeter wave frequency; variable η1=0.955r p r t 0.68 +0.006ρ; variable r t =288 / (273+t);

[0049] t is temperature; ρ is water vapor density; function f i is the frequency parameter.

[0050] As one of the improvements to the above technical solution, in step 3, A test_atm and A real_atm The calculation formulas are:

[0051] A test_atm =(γ test_o +γ test_w )·r0

[0052] A real_atm =(γ real_o +γ real_w )·r0

[0053] Where r0 represents the path length.

[0054] As one of the improvements to the above technical solution, in step 4, A atm_mod The calculation formula is:

[0055] A atm_mod =A test_atm -A real_atm .

[0056] As one of the improvements to the above technical solution, in step 5, E real The calculation formula is:

[0057] E real =E test +A atm_mod .

[0058] The present invention proposes a method for correcting the characteristic loss of harmonic spurious radiation emission of millimeter-wave frequency band antennas, which has the following advantages:

[0059] 1. The method proposed in this paper, based on the International Telecommunication Union's ITU-R P.676-10 recommendation, quantitatively provides an approximate estimation model and transmission characteristics for atmospheric characteristic losses in millimeter-wave frequency band devices. This method can correct the test results of harmonic spurious radiation emissions of millimeter-wave device antennas, providing an important theoretical basis for electromagnetic compatibility testing in the millimeter-wave frequency band and helping to improve the accuracy of electromagnetic compatibility antenna harmonic spurious radiation emission tests. It has important research value.

[0060] 2. The method proposed in the present invention theoretically corrects the test results of the harmonic spurious radiation emission of millimeter-wave device antennas, avoiding the high cost of simulating the actual working environment (including temperature, humidity, and other conditions) of the device in order to perform the harmonic spurious radiation emission test of the millimeter-wave device antennas. It is easy to implement and has important engineering application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0061] Figure 1 Schematic diagram of the test arrangement for harmonic spurious radiation emission of millimeter wave frequency band equipment antennas and correction of characteristic loss effects;

[0062] Figure 2 : is a characteristic loss curve caused by atmospheric gases in the frequency band of 1 to 300 GHz at sea level in the embodiment;

[0063] Figure 3 is the atmospheric loss value of the far-field test environment;

[0064] Figure 4 It is the atmospheric loss value of the actual working environment of the equipment. DETAILED DESCRIPTION

[0065] The present invention relates to the field of electromagnetic compatibility (EMC) testing and concerns the testing of harmonic spurious radiation emissions from millimeter-wave device antennas. Specifically, it provides a method for correcting characteristic loss of harmonic spurious radiation emissions from millimeter-wave device antennas, which is used to correct test data after testing for harmonic spurious radiation emissions from millimeter-wave device antennas. Based on the International Telecommunication Union's ITU-R P.676-10 recommendation, the method quantitatively provides an approximate estimation model and transmission characteristics for atmospheric loss in the millimeter-wave band. This method theoretically corrects the test results for harmonic spurious radiation emissions from millimeter-wave device antennas, avoiding the high cost of simulating the device's actual operating environment (including temperature, humidity, and other conditions) for this purpose. This method provides an important theoretical foundation for implementing electromagnetic compatibility (EMC) testing in the millimeter-wave band, helps improve the accuracy of EMC antenna harmonic spurious radiation emission test results, and has significant academic and engineering application value.

[0066] A method for correcting the characteristic loss of harmonic spurious radiation emission of a millimeter-wave frequency band antenna comprises the following steps:

[0067] Step 1: Calculate the characteristic loss γ under dry air conditions o (dB / km):

[0068] For f≤54GHz:

[0069]

[0070] For 54GHz<f≤60GHz:

[0071]

[0072] For 60GHz<f≤62GHz:

[0073]

[0074] For 62GHz<f≤66GHz:

[0075]

[0076] For 66GHz<f≤120GHz:

[0077]

[0078] For 120GHz<f≤350GHz:

[0079]

[0080] Step 2: Calculate the characteristic loss γ under water vapor conditions w (dB / km), that is:

[0081]

[0082] Step 3: Assume that the millimeter wave transmission path is a horizontal path or a slightly inclined path close to the ground, the measurement condition is a clear sky, and the atmosphere is modeled as a standard atmosphere with an atmospheric characteristic loss value A atm It can be expressed as follows:

[0083] A atm =γ·r0=(γ o +γ w )·r0 dB

[0084] Step 4: Calculate the antenna harmonic spurious radiation emission correction result of the millimeter wave frequency band device, that is,

[0085] E real =E test +A atm_mod

[0086] Among them, E real It represents the corrected antenna harmonic spurious radiation emission result of the millimeter wave frequency band device; E test A represents the result of direct testing of the antenna harmonic spurious radiation emission of millimeter wave frequency band equipment in the far-field test environment receiver. atm_mod The atmospheric loss correction factor for the harmonic spurious radiation emission of millimeter wave band equipment antenna is defined as

[0087] A atm_mod =A test_atm -A real_atm

[0088] Among them, A test_atm Indicates the atmospheric loss value of millimeter wave in far-field test environment; A real_atm Indicates the atmospheric loss value of the actual working environment of millimeter wave frequency band equipment.

[0089] The technical solution provided by the present invention is further illustrated below with reference to embodiments.

[0090] This embodiment provides a method for correcting the characteristic loss of harmonic spurious radiation emission of millimeter wave frequency antennas. The test and correction diagram is shown in FIG. Figure 1 The loss of electromagnetic waves radiated by millimeter-wave devices in the clear atmosphere is primarily due to absorption by dry air (primarily oxygen) and water vapor. By summing the resonance lines of oxygen and water vapor at any temperature and humidity, the loss of millimeter-wave signals in atmospheric gases can be calculated fairly accurately. Characteristic atmospheric loss is a function of frequency, pressure, temperature, and water vapor density. The characteristic radio wave loss caused by dry air and water vapor from sea level to an altitude of 10 km can be estimated using the following simplified algorithm.

[0091] The specific steps are as follows:

[0092] Accurately calculate the characteristic loss γ under dry air conditions o and characteristic loss γ under water vapor conditions w The following is a curve fitting method based on line-by-line calculation recommended by ITU-R P.676-10, which gives the γ o and γ w The approximate calculation formula of the standard atmospheric characteristic loss calculated by this method is accurate to about ±10%.

[0093] Step 1: Calculate the characteristic loss γ under dry air conditions o (dB / km), that is

[0094] For f≤54GHz:

[0095]

[0096] For 54GHz<f≤60GHz:

[0097]

[0098] For 60GHz<f≤62GHz:

[0099]

[0100] For 62GHz<f≤66GHz:

[0101]

[0102] For 66GHz<f≤120GHz:

[0103]

[0104] For 120GHz<f≤350GHz:

[0105]

[0106] in:

[0107]

[0108]

[0109]

[0110]

[0111]

[0112]

[0113]

[0114]

[0115]

[0116]

[0117]

[0118]

[0119]

[0120]

[0121]

[0122] in:

[0123] f: frequency (GHz)

[0124] r p =p / 1013

[0125] rt =288 / (273+t)

[0126] p: pressure (hPa)

[0127] t: temperature (℃)

[0128] Step 2: Calculate the characteristic loss γ under water vapor conditions w (dB / km), that is:

[0129]

[0130] in,

[0131] η1=0.955r p r t 0.68 +0.006ρ

[0132] η2=0.735r p r t 0.5 +0.0353r t 4 ρ

[0133]

[0134] ρ is the water vapor density in g / m 3 .

[0135] Step 3: Assume that the millimeter wave transmission path is a horizontal path or a slightly inclined path close to the ground, the measurement condition is a clear sky, and the atmosphere is modeled as a standard atmosphere with an atmospheric characteristic loss value A atm It can be expressed as follows:

[0136] A atm =γ·r0=(γ o +γ w )·r0 dB

[0137] in,

[0138] r0: path length, in km.

[0139] γ o : frequency-dependent characteristic loss under dry air conditions (dB / km);

[0140] γ w : frequency-dependent characteristic loss under water vapor conditions (dB / km);

[0141] Step 4: Calculate the antenna harmonic spurious radiation emission correction result of the millimeter wave frequency band device, that is,

[0142] Ereal =E test +A atm_mod

[0143] in,

[0144] E real : Corrected antenna harmonic spurious radiation emission results of millimeter wave frequency band equipment;

[0145] E test : Antenna harmonic spurious radiation emission results of millimeter-wave frequency band devices obtained by direct testing in a far-field test environment;

[0146] A atm_mod :The atmospheric characteristic loss correction factor for the harmonic spurious radiation emission of millimeter wave band equipment antenna is defined as

[0147] A atm_mod =A test_atm -A real_atm

[0148] in,

[0149] A test_atm : The atmospheric characteristic loss value of the millimeter wave in the far-field test environment can be calculated through step 3 if the far-field test environment (including temperature, humidity, atmospheric pressure, etc.) is known;

[0150] A real_atm : The atmospheric characteristic loss value of the actual working environment of the millimeter wave band device can be calculated through step 3 when the actual working environment of the millimeter wave band device (including temperature, humidity, atmospheric pressure, etc.) is known.

[0151] The feasibility of the present invention is illustrated below through typical embodiments.

[0152] Simulation 1: Figure 2 Given the pressure of 1013hPa, temperature of 20℃, water vapor density of 25g / m 3 , under the condition that the distance between the device under test and the antenna is 30m, the characteristic loss curve caused by atmospheric gases in the 1 to 300GHz band at sea level, including the moist air characteristic loss (blue dashed line), the dry air characteristic loss (red dotted line) and the total characteristic attenuation obtained by accumulating dry air and moist air (black solid line). Figure 2 The results show that when millimeter-wave signals propagate in the atmosphere, the characteristic loss varies at different frequencies due to the absorption of water vapor and oxygen molecules. The characteristic loss is relatively small near 30 GHz, 84 GHz, 131 GHz, and 214 GHz, which are called atmospheric windows. Maximum values, called loss peaks, appear near 23 GHz, 60 GHz, 119 GHz, and 183 GHz.

[0153] Simulation 2: Assuming the atmospheric pressure of the test environment is 1013hPa and the water vapor density is 70g / m 3 , the temperature is 10℃, the distance between the device under test and the antenna is 30m, and the atmospheric pressure of the actual working environment of the device is 0hPa and the water vapor density is 0g / m 3 , the temperature is 0℃, and the distance between the device under test and the antenna is 30m.

[0154] Figure 3 and Figure 4 The atmospheric characteristic loss curve A of the far-field test environment is given respectively test_atm And the atmospheric characteristic loss curve A of the actual working environment of the equipment real_atm , according to formula A atm_mod =A test_atm -A real_atm It is calculated that at 183.4 GHz (the absorption peak of water vapor), the atmospheric characteristic loss correction factor for the harmonic spurious radiation emission of the millimeter wave band device antenna is approximately A atm_mod =7.081dB. Therefore, under this condition, the antenna harmonic spurious radiation emission data measured by the receiver plus 7.081dB is the antenna harmonic spurious radiation emission result in the actual working environment of the equipment.

[0155] From the above detailed description of the present invention, it can be seen that the method proposed in the present invention theoretically corrects the test results of the harmonic spurious radiation emission of the millimeter wave device antenna, thereby avoiding the high cost of simulating the actual working environment of the device (including temperature, humidity and other conditions) in order to implement the harmonic spurious radiation emission test of the millimeter wave device antenna, and is easy to implement.

[0156] Finally, it should be noted that the above embodiments are intended only to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the embodiments, it should be understood by those skilled in the art that modifications or equivalent substitutions to the technical solutions of the present invention do not depart from the spirit and scope of the technical solutions of the present invention and are intended to be encompassed by the claims of the present invention.

Claims

1. A method for correcting the characteristic loss of harmonic spurious radiation emission of a millimeter-wave frequency band antenna, the method comprising: Step 1: Calculate the characteristic loss γ of the far-field test environment under dry air conditions based on the far-field test environment parameters and actual working environment parameters of the millimeter wave frequency band device. test_o and the characteristic loss γ of the actual working environment real_o ; Step 2: Calculate the characteristic loss γ of the far-field test environment under water vapor conditions based on the far-field test environment parameters and actual working environment parameters of the millimeter wave frequency band device. test_w and the characteristic loss γ of the actual working environment rea l _w ; Step 3: γ calculated according to step 1 test_o and γ real_o , γ calculated in step 2 test_w and γ real_w And the path length, further calculate the atmospheric characteristic loss value A of the millimeter wave frequency band far-field test environment test_atm And the atmospheric characteristic loss value A of the actual working environment real_atm ; Step 4: Based on the A calculated in step 3 test_atm and A real_atm , calculate the atmospheric characteristic loss correction factor A of the harmonic spurious radiation emission of the millimeter wave band device antenna atm_mod ; Step 5: Obtain the antenna harmonic spurious radiation emission of the millimeter wave frequency band device directly tested by the receiver in the far-field test environment. test , and A calculated according to step 4 atm_mod The calculated correction result E of the antenna harmonic spurious radiation emission of the millimeter wave frequency band device is real .

2. The method for correcting the characteristic loss of harmonic spurious radiation emission of millimeter wave frequency band antennas according to claim 1, characterized in that: In step 1, γ test_o and γ real_o γ is calculated by the following o The formula is calculated, where γ is calculated test_o When the temperature and pressure of the far-field test environment are used, γ is calculated. real_o When using the actual working environment temperature and pressure; For f≤54GHz, γ o The calculation formula is: Among them, the variable r t =288 / (273+t), t is temperature; f is millimeter wave frequency; variable r p =p / 1013, where p is the pressure; the variables ξ1, ξ2, and ξ3 are: function express: a, b, c, d represent variables respectively: For 54GHz<f≤60GHz, γ o The calculation formula is: Among them, the variable γ 54 , γ 58 , γ 60 They are: For 60GHz<f≤62GHz, γ o The calculation formula is: Among them, the variable For 62GHz<f≤66GHz, γ o The calculation formula is: Among them, the variable γ 64 and γ 66 They are: For 66GHz<f≤120GHz, γ o The calculation formula is: Among them, variables ξ4, ξ5, ξ6 and ξ7 are: For 120GHz<f≤350GHz, γ o The calculation formula is: Among them, the variable 3. The method for correcting the characteristic loss of harmonic spurious radiation emission of millimeter wave frequency band antennas according to claim 1, characterized in that: In step 2, γ test_w and γ real_w γ is calculated by the following w The formula is calculated, where γ is calculated test_w When , use the temperature and water vapor density of the far-field test environment; calculate γ real_w When using the actual working environment temperature and water vapor density; Where f is the millimeter wave frequency; the variable variable r t =288 / (273+t); t is temperature; ρ is water vapor density; function f i is the frequency parameter.

4. The method for correcting the characteristic loss of harmonic spurious radiation emission of millimeter wave frequency band antennas according to claim 1, characterized in that: In step 3, A test_atm and A real_atm The calculation formulas are: A test_atm =(γ test_o +g test_w )·r0 A real_atm =(γ real_o +g real_w )·r0 Where r0 represents the path length.

5. The method for correcting the characteristic loss of harmonic spurious radiation emission of millimeter wave frequency band antennas according to claim 1, characterized in that: In step 4, A atm_mod The calculation formula is: A atm_mod =A test_atm -A real_atm 。 6. The method for correcting the characteristic loss of harmonic spurious radiation emission of millimeter wave frequency band antennas according to claim 1, characterized in that: In step 5, E real The calculation formula is: AND real =And test +A atm_mod 。

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