A compact field polarization calibration method

Abstract

The present invention discloses a compact field polarization calibration method, comprising: establishing a compact field test environment; performing a first polarization first test, a second test, and a second polarization test on an antenna to be tested, respectively obtaining a far-field amplitude pattern and a phase pattern; obtaining an amplitude correction factor and a phase correction factor by analyzing the two test results of the first polarization, and correcting the second polarization test result to obtain the amplitude pattern and the phase pattern of the antenna to be tested. Through this method, the accuracy of the compact field test antenna is improved, especially for the compact field in the terahertz frequency band, because the wavelength is shorter and the position deviation has a more severe impact, the effect of this correction method is more obvious.

Description

Technical Field

[0001] The invention relates to a compact field calibration method, in particular to a compact field polarization calibration method, and belongs to the technical field of antenna measurement. Background Art

[0002] A compact antenna is a test device that uses a correction unit to convert the spherical wave radiated by the feed horn into a plane wave at a close distance. Errors in the processing, assembly, and calibration of the compact antenna have a significant impact on the test results of the antenna, especially the test results of the cross-polarization of circularly polarized antennas. When the cross-polarization isolation is at the order of 20dB, a 2° phase error and a 0.2dB amplitude error will both result in a 1dB cross-polarization test error, indicating that the cross-polarization parameters of circularly polarized antennas are very sensitive to errors.

[0003] With the development of antennas, the frequency is getting higher and higher. After entering the terahertz frequency band, due to the very short wavelength, the same magnitude of position error will cause a larger phase error compared to low frequency. The phase error introduced by polarization switching will be much larger than 2°, which will cause a larger cross-polarization test error for circularly polarized antennas, seriously affecting the test results. Summary of the invention

[0004] The technical problem solved by the present invention is: to overcome the shortcomings of the prior art, the present invention proposes a compact field polarization calibration method, calculates the amplitude difference and phase difference of the compact field when testing the two polarization components of the amplitude directional diagram and the phase directional diagram, corrects the test result error caused by polarization switching, obtains the corrected amplitude directional diagram and phase directional diagram test results, and improves the test accuracy.

[0005] The technical solution of the present invention is:

[0006] A compact field polarization calibration method, comprising:

[0007] (S1) Establishing a compact test field environment, installing the antenna to be tested and the feed source of the corresponding frequency in the compact field, and calibrating the compact field;

[0008] (S2) performing a first polarization first test on the antenna to be tested, and obtaining a far-field amplitude pattern amH_0 and a phase pattern phH_0 of the first polarization first test;

[0009] (S3) rotating the feed of the compact field or reinstalling the feed so that the polarization direction of the feed is 90 degrees to that of the feed in (S2), performing a second polarization test on the antenna to be tested, and obtaining a far-field amplitude pattern amV_0 and a phase pattern phV_0 of the second polarization test;

[0010] (S4) rotating the antenna to be tested or reinstalling the antenna to be tested so that the polarization direction of the antenna to be tested is 90 degrees to that of the antenna to be tested in (S2), performing a second test of the first polarization on the antenna to be tested, and obtaining a far-field amplitude pattern amH_90 and a phase pattern phH_90 of the second test of the first polarization;

[0011] (S5) based on the far-field amplitude pattern and phase pattern obtained in (S2) and (S4), respectively, a reference point is selected, and the amplitude and phase of the reference point in the far-field amplitude pattern and phase pattern of the first test and the second test of the first polarization are calculated, respectively, the amplitude correction factor Δam is the difference between the two amplitudes obtained, and the phase correction factor Δph is the difference between the two phases obtained;

[0012] (S6) According to the amplitude correction factor and phase correction factor obtained in (S5), the far-field amplitude pattern and phase pattern obtained in (S3) are corrected to obtain the test results of the far-field amplitude pattern and phase pattern of the antenna to be tested.

[0013] Preferably, in (S4), if the selected reference point is a point that has been collected in the far-field amplitude pattern and phase pattern of the first test and the second test of the first polarization, the corresponding amplitude and phase are directly obtained; otherwise, quadratic surface fitting is performed using the least squares method according to the coordinates of the points collected around the reference point in the amplitude pattern and the phase pattern, respectively; based on the fitting results, the amplitude and phase of the reference point in the first test and the second test of the first polarization are respectively obtained.

[0014] Preferably, the coefficients of the fitting surface are not less than 10, and the number of surrounding collected points is not less than 9.

[0015] Preferably, the phase pattern needs to be subjected to phase unwrapping processing before the least square method is used to calculate the reference point phase value, that is, the original range of ±180 degrees is recalculated into a range of ±∞.

[0016] Preferably, the reference point is within a selected area of ​​a far-field amplitude pattern obtained from any test of the first polarization of the antenna to be tested, and the selected area needs to include a main lobe range of the selected pattern.

[0017] Preferably, the boundary of the selected area is an elliptical curve formed by the maximum value drop MdB in the selected directional pattern, and M is between 3 and 10; the reference point is located at the center of the ellipse, and the coordinates of the center of the ellipse (Az mid ,El mid ) is calculated as follows:

[0018]

[0019]

[0020] Where:

[0021] Az mid is the azimuth coordinate of the reference point of the selected directional pattern, El mid is the elevation coordinate of the reference point of the selected pattern, Az max Az is the maximum azimuth coordinate of the reference level curve of the selected reference point in the directional diagram, min is the minimum azimuth coordinate of the reference level curve of the selected reference point in the directional diagram, El max is the maximum elevation coordinate of the reference level curve of the reference point in the selected directional diagram, El min It is the minimum elevation coordinate value of the reference level curve of the reference point in the selected directional pattern.

[0022] Preferably, in (S2)(S3)(S4), the scanning range is the range that needs to be investigated for the antenna pattern to be measured, and the sampling interval is no greater than one tenth of the beam width.

[0023] Preferably, in (S4), if the antenna to be tested is rotated, the rotation direction is consistent with the rotation direction of the feed source, that is, the antenna to be tested rotates clockwise.

[0024] Preferably, if the antenna to be tested is a linearly polarized antenna, (S6) the corrected amplitude pattern amV′_0 and phase pattern phV′_0 are the far-field amplitude pattern and phase pattern test results of the antenna to be tested:

[0025] amV′_0=amV_0-Δam

[0026] phV′_0=phV_0-Δph.

[0027] Preferably, if the antenna to be tested is a circularly polarized antenna, the far-field amplitude pattern and phase pattern of the antenna to be tested are calculated based on the corrected amplitude pattern amV′_0 and phase pattern phV′_0 calculated in (S6) and the far-field amplitude pattern amH_0 and phase pattern phH_0 of the first polarization first test obtained in (S2), and the far-field amplitude pattern and phase pattern test results of the antenna to be tested are obtained:

[0028] amV′_0=amV_0-Δam

[0029] phV′_0=phV_0-Δph

[0030]

[0031]

[0032]

[0033]

[0034] Where am_R is the amplitude of right-hand circular polarization after circular polarization synthesis, am_L is the amplitude of left-hand circular polarization after circular polarization synthesis, ph_R is the phase of right-hand circular polarization after circular polarization synthesis, ph_L is the phase of left-hand circular polarization after circular polarization synthesis, abs is the modulus operation of complex numbers, angle is the phase angle operation of complex numbers, and j is the symbol of the complex number j 2 =-1, π is the ratio of a circle to a circumference of ...

[0035] The beneficial effects of the present invention compared with the prior art are:

[0036] (1) The present invention solves the inconsistency problem of the two polarizations during the compact field polarization test by only using the compact field test system's own conditions, corrects the position deviation caused by the rotation or installation of the two polarizations of the feed source and the amplitude and phase inconsistency of the two polarizations of the compact field itself, and improves the accuracy of the compact field test antenna. Especially in the terahertz frequency band, due to the shorter wavelength, the position deviation has a more severe impact, and the effect of this correction method is more obvious.

[0037] (2) The present invention obtains the amplitude and phase deviation of different polarizations of the compact field through data processing and calculation, thereby improving the test accuracy of the antenna; especially for the compact field in the terahertz frequency band, the error in the feed position is more obvious in the terahertz frequency band, and correction is more necessary.

[0038] (3) The introduction of the correction reference point of the present invention can avoid the error caused by the pointing deviation of the amplitude pattern and the phase pattern due to the feed position deviation, and the correction accuracy is higher. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 A flow chart of a compact field polarization calibration method of the present invention;

[0040] Figure 2 A schematic diagram of selecting reference points for directional pattern correction in an embodiment of the present invention;

[0041] Figure 3 A schematic diagram of the position of directional pattern data used to calculate the amplitude and phase of a reference point in an embodiment of the present invention;

[0042] Figure 4 This is the directional pattern of a terahertz antenna before correction according to an embodiment of the present invention;

[0043] Figure 5 This is the radiation pattern of a terahertz antenna in an embodiment of the present invention after being corrected using the method of this patent. DETAILED DESCRIPTION

[0044] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments, which are as follows:

[0045] A compact field polarization calibration method, comprising: Figure 1 The steps described:

[0046] (1) Install and calibrate the antenna to be tested

[0047] Establish a compact test environment: The compact test environment includes a reflector, a feed, a feed turntable, a turntable for the antenna to be tested, a radio frequency instrument, and test software. The feed is placed on the feed turntable, and the reflector converts the spherical electromagnetic wave emitted by the feed into a quasi-plane wave. The radio frequency instrument generates, transmits, and collects electromagnetic wave signals of the required test frequency band, and the test software is used to control the above hardware.

[0048] The antenna turntable to be tested consists of three rotating axes: azimuth, elevation and polarization. The plane formed by the rotation of the turntable's azimuth axis is generally parallel to the ground, and the direction perpendicular to the vertical line of the plane is the Y axis, which is generally defined as upward; the vertical line of the plane formed by the rotation of the polarization axis is the Z axis, and the positive direction points to the direction of the incoming wave; the Y axis is determined using the right-hand system; the coordinate origin O is the intersection of the rotation centers of each axis.

[0049] Install the antenna to be tested: Place the antenna to be tested on the antenna turntable and place it within the quasi-plane wave output by the reflecting surface.

[0050] Calibration site: Select the feed source of the corresponding frequency for the antenna to be tested and install it on the feed turntable. Establish a definite relationship between the coordinate system of the antenna to be tested and the coordinate system of the site or adjust them so that the three axes are parallel. The adjustment process can be assisted by mechanical measuring equipment such as theodolite and laser tracker.

[0051] (2) Test the first polarization pattern data

[0052] Set the test software parameters: set the scanning range, sampling interval, and test frequency. The scanning range is the range that needs to be investigated for the corresponding antenna pattern; the sampling interval is the location density of the antenna pattern acquisition, which is generally required to be no greater than one tenth of the beam width. For example, if the antenna pattern beam width is 5 degrees, the sampling interval setting cannot be greater than 0.5 degrees; the test frequency is the typical frequency value within the nominal frequency operating range of the antenna. These frequencies can be equally spaced or unequally spaced. For example, when the antenna frequency range is 1.1GHz~1.46GHz, it is a list of frequencies to be tested for the antenna, such as: 1.1GHz, 1.2GHz, 1.32GHz, 1.4GHz, 1.46GHz, etc.

[0053] The test software automatically rotates the turntable of the antenna to be tested and controls the RF transmission signal, collects and records the amplitude and phase pattern data, completes the first polarization pattern test of the antenna to be tested point by point, and obtains the far-field amplitude pattern amH_0 and phase pattern phH_0 of the first polarization. Among them, the test range needs to include the main lobe range of the pattern, at least including the range covered by the pattern drop MdB, the drop level M should be between 3 and 10, if the pattern width ≤5 degrees, 3 is preferred, if the pattern width is wider, the value is appropriately enlarged to improve the stability of the reference point.

[0054] (3) Rotate the compact field feed or reinstall it so that it is 90 degrees with the original feed polarization direction. If the original feed polarization is horizontal polarization, it will be vertical polarization after rotation. The rotation direction is preferably rotated in a clockwise direction facing the feed. Perform a second polarization test on the antenna to be tested to obtain the far-field amplitude pattern amV_0 and phase pattern phV_0 of the second polarization. Among them, the test range needs to include the main lobe range of the pattern, at least including the range covered by the pattern drop MdB.

[0055] (4) Use the polarization axis of the antenna turntable to rotate the antenna to be tested or reinstall it so that it is 90 degrees to the original polarization direction. The rotation direction is consistent with the rotation direction of the feed source, that is, it rotates clockwise facing the antenna to be tested. Perform a second test on the first polarization of the antenna to obtain the far-field amplitude pattern amH_90 and phase pattern phH_90 of the second test of the first polarization. Among them, the test range needs to include the main lobe range of the pattern, at least including the range covered by the pattern drop MdB.

[0056] (5) Use the test results of steps (2) and (4) to solve the amplitude correction factor Δam and the phase correction factor Δph.

[0057] (51) Select a reference point for the directional pattern position in steps (2) and (4)

[0058] After the reference point is rotated at the feed source and the antenna, the test result is the directional pattern of the same antenna with the same polarization in two different field polarizations in the same compact field. If there is no error, the amplitude and phase should be completely consistent at the same directional pattern position. Therefore, in order to correct the error, the same position of the two test directional patterns must be determined first.

[0059] Terahertz antennas are mainly circular beams, but in engineering, it is impossible to form a standard circle, which is closer to an ellipse. The center of the ellipse is selected as the reference point for calculating the correction value. The determination method is to use the elliptical curve formed by the maximum drop in the radiation pattern MdB to calculate the reference point coordinates (Az mid ,El mid ):

[0060]

[0061]

[0062] Where:

[0063] Az mid is the azimuth coordinate of the reference point of the selected directional pattern.

[0064] El mid is the azimuth coordinate of the reference point of the selected directional pattern.

[0065] Az max It is the maximum azimuth coordinate of the reference level curve of the selected directional pattern reference point.

[0066] Az min It is the minimum azimuth coordinate of the reference level curve of the selected directional pattern reference point.

[0067] El max It is the maximum elevation coordinate of the reference level curve of the selected reference point in the directional pattern.

[0068] El min It is the minimum elevation coordinate value of the reference level curve of the reference point in the selected directional pattern.

[0069] like Figure 2 As shown, this point must be the center of the ellipse at any inclination angle of the ellipse. The advantage of this method is that there is no need to perform complex ellipse equation calculations, and the coordinates of the reference point can be obtained by only using the position of the coordinates of the directional pattern level.

[0070] (52) Based on the directional pattern data obtained in steps (2) and (4), calculate the reference point coordinates (Az mid ,El mid )'s amplitude and phase

[0071] The sampling points of the directional pattern of the compact field test are a two-dimensional matrix point set, which cannot achieve continuous sampling. The selected reference point generally does not fall exactly on the sampling point.

[0072] The method for obtaining the amplitude and phase of the reference point adopted by the present invention is to use the amplitude and phase values ​​and coordinates of the points around the reference point in the directional diagram, use the least squares method to perform quadratic surface fitting, and then obtain the amplitude and phase values ​​of the reference point. Figure 3 The star is the position of the original collected directional pattern. The surrounding points are the point in the middle of the directional pattern, the 8 points in the first circle closest to the reference point, and the 16 points in the second circle. Figure 3 The triangle is the position of the reference point. The coordinates and amplitude of the star point are substituted into the following formula to obtain an overdetermined system of N equations, which can be used to solve the amplitude and phase values ​​of the triangle points with known coordinates.

[0073] In the amplitude pattern data amH_0, select the n data and coordinate information closest to the reference point in the pattern, substitute them into the following formula, and use the least squares method to calculate the coefficients a~k:

[0074]

[0075] Where:

[0076] x n Represents the azimuth coordinate of the nth point in the directional pattern.

[0077] y n Represents the elevation coordinate of the nth point in the directional pattern.

[0078] z n Represents the amplitude or phase value of the directional pattern at the nth point.

[0079] n represents the number of the selected point in the directional diagram, n≥9.

[0080] a~k represent the coefficients of the fitted amplitude and phase pattern surface, and the calculation formula is as follows:

[0081]

[0082] Let the matrix on the left be A, and the matrix composed of a~k be L

[0083] Then the solution of the homogeneous overdetermined equation AL=0 is the value of a~k.

[0084] L=A + A=(A T A) -1 ·A T

[0085] Where A + Represents the generalized inverse of the matrix A.

[0086] A T Represents the transpose of A.

[0087] (A T A) -1 Representative seeking A T The standard inverse of A.

[0088] The values ​​of 1 to 10 in L are obtained, which are the values ​​of a to k. Then the coordinates of the reference point (Az mid ,El mid ) into the surface equation with all parameters a to k known, where Az mid Substitute x, El mid Substitute y into the equation and find the value of z. For the two roots of the quadratic equation, choose the roots that are close to the average of the surrounding values.

[0089] If the reference point phase is to be solved, the z in the A matrix is ​​substituted into the phase value, and the phase pattern needs to be "phase unwrapped" before being substituted into the formula, that is, the original ±180 degree range is recalculated as the ±∞ range.

[0090] Assume that the amplitude of the reference point corresponding to the amplitude pattern data amH_0 obtained in the first test of the first polarization of the antenna to be tested is amH mid _0, the phase of the reference point corresponding to the obtained phase pattern data phH_0 is phH mid _0.

[0091] Similarly, the amplitude and phase of the reference point obtained from the second test of the first polarization of the antenna under test are amH mid _90 and phH mid _90.

[0092] (53) Calculate the amplitude correction factor and phase correction factor:

[0093] Δam=amH mid _90-amH mid _0

[0094] Δph=phH mid _90-phH mid _0

[0095] (6) Based on the above two correction factors, the directional pattern tested in step (3) is corrected to obtain the corrected amplitude directional pattern amV′_0 and phase directional pattern phV′_0.

[0096] amV′_0=amV_0-Δam

[0097] phV′_0=phV_0-Δph

[0098] Usually, for the versatility of the antenna test system, a single-line polarization feed is used in a compact range. Two tests (two polarizations) are performed during the antenna test, and then the circular polarization is synthesized through data processing to obtain the circular polarization pattern.

[0099] If the antenna to be tested is a linearly polarized antenna, the corrected amplitude pattern amV′_0 and phase pattern phV′_0 are the final pattern test results of the antenna to be tested.

[0100] If the antenna to be tested is a circularly polarized antenna, the above correction result and the result obtained in step (2) are used for calculation and processing to obtain the final amplitude radiation pattern and phase radiation pattern test results of the antenna to be tested. The specific calculation method is as follows:

[0101] The amplitude pattern amH_0 and the phase pattern phH_0 of the first polarization acquisition are calculated, and the amplitude pattern amV′_0 and the phase pattern phV′_0 of the second polarization correction are calculated:

[0102] First, the amplitude and phase are averaged into complex field strength representation:

[0103]

[0104]

[0105] Where EH is the complex field strength of horizontal polarization;

[0106] EV is the complex field strength of vertical polarization.

[0107] The complex field strength of left-hand and right-hand circular polarization is calculated:

[0108]

[0109]

[0110] Where ER is the complex field strength of right-hand circular polarization;

[0111] EL is the complex field strength of left-hand circular polarization.

[0112] The complex field intensity is further converted into amplitude and phase representation:

[0113] am_R=20log 10 (abs(ER))

[0114] am_L=20log 10 (abs(EL))

[0115] ph_R=angle(ER) / π·180

[0116] ph_L=angle(EL) / π·180

[0117] Putting the calculation process together, we get the following results:

[0118]

[0119]

[0120]

[0121]

[0122] Where:

[0123] am_R is the amplitude of right-hand circular polarization after circular polarization synthesis,

[0124] am_L is the amplitude of left-hand circular polarization after circular polarization synthesis,

[0125] ph_R is the phase of right-hand circular polarization after circular polarization synthesis,

[0126] ph_L is the phase of left-hand circular polarization after circular polarization synthesis,

[0127] abs is the modulus operation for complex numbers.

[0128] angle is the phase angle operation of the complex number.

[0129] j is the complex symbol j 2 =-1,

[0130] π is the ratio of a circle to its circumference.

[0131] The calculated right-hand amplitude and phase patterns are am_R and ph_R, and the left-hand amplitude and phase patterns are am_L and ph_L, which are the final amplitude and phase pattern test results of the antenna to be tested.

[0132] Figure 4 This is the 80GHz circular polarization radiation pattern of a certain reflector antenna before correction. It can be seen that the cross-polarization is only -20dB, which is far from the simulation result of -30dB. Figure 5 This is the result after correction using the method of the present invention. It can be seen that the cross-polarization has basically approached the -30 dB level, which illustrates the effectiveness of the present invention.

[0133] The contents not described in detail in the specification of the present invention belong to the common knowledge of the professionals in this field.

Claims

1. A compact field polarization calibration method, characterized in that: include: (S1) Establishing a compact test field environment, installing the antenna to be tested and the feed source of the corresponding frequency in the compact field, and calibrating the compact field; (S2) performing a first polarization first test on the antenna to be tested, and obtaining a far-field amplitude pattern amH_0 and a phase pattern phH_0 of the first polarization first test; (S3) rotating the feed of the compact field or reinstalling the feed so that the polarization direction of the feed is 90 degrees to that of the feed in (S2), performing a second polarization test on the antenna to be tested, and obtaining a far-field amplitude pattern amV_0 and a phase pattern phV_0 of the second polarization test; (S4) rotating the antenna to be tested or reinstalling the antenna to be tested so that the polarization direction of the antenna to be tested is 90 degrees to that of the antenna to be tested in (S2), performing a second test of the first polarization on the antenna to be tested, and obtaining a far-field amplitude pattern amH_90 and a phase pattern phH_90 of the second test of the first polarization; (S5) based on the far-field amplitude pattern and phase pattern obtained in (S2) and (S4), respectively, a reference point is selected, and the amplitude and phase of the reference point in the far-field amplitude pattern and phase pattern of the first test and the second test of the first polarization are calculated, respectively, the amplitude correction factor Δam is the difference between the two amplitudes obtained, and the phase correction factor Δph is the difference between the two phases obtained; (S6) According to the amplitude correction factor and phase correction factor obtained in (S5), the far-field amplitude pattern and phase pattern obtained in (S3) are corrected to obtain the test results of the far-field amplitude pattern and phase pattern of the antenna to be tested.

2. A compact field polarization calibration method according to claim 1, characterized in that: In (S4), if the selected reference point is a point that has been collected in the far-field amplitude pattern and phase pattern of the first test and the second test of the first polarization, the corresponding amplitude and phase are directly obtained; otherwise, quadratic surface fitting is performed using the least squares method according to the coordinates of the points that have been collected around the reference point in the amplitude pattern and the phase pattern; based on the fitting results, the amplitude and phase of the reference point in the first test and the second test of the first polarization are respectively obtained.

3. A compact field polarization calibration method according to claim 2, characterized in that: The coefficients of the fitted surface shall not be less than 10, and the number of surrounding collected points shall not be less than 9.

4. The method for compact field polarization calibration according to claim 2, characterized in that: Before the phase value of the reference point is calculated by the least square method, the phase pattern needs to be phase unwrapped, that is, the original range of ±180 degrees is recalculated into the range of ±∞.

5. The compact field polarization calibration method according to claim 1, characterized in that: The reference point is within a selected area of ​​the far-field amplitude pattern obtained from any test of the first polarization of the antenna to be tested, and the selected area needs to include the main lobe range of the above selected pattern.

6. A compact field polarization calibration method according to claim 5, characterized in that: Preferably, the boundary of the selected area is an elliptical curve formed by the maximum value drop MdB in the selected directional pattern, and M is between 3 and 10; the reference point is located at the center of the ellipse, and the coordinates of the center of the ellipse (Az mid ,El mid ) is calculated as follows: Where: Az mid is the azimuth coordinate of the reference point of the selected directional pattern, El mid is the elevation coordinate of the reference point of the selected pattern, Az max Az is the maximum azimuth coordinate of the reference level curve of the selected reference point in the directional diagram, min is the minimum azimuth coordinate of the reference level curve of the selected reference point in the directional diagram, El max is the maximum elevation coordinate of the reference level curve of the reference point in the selected directional diagram, El min It is the minimum elevation coordinate value of the reference level curve of the reference point in the selected directional pattern.

7. The compact field polarization calibration method according to claim 1, characterized in that: In (S2)(S3)(S4), the scanning range is the range that needs to be investigated for the antenna pattern to be measured, and the sampling interval is no greater than one tenth of the beam width.

8. The compact field polarization calibration method according to claim 1, characterized in that: In (S4), if the antenna to be tested is rotated, the rotation direction is consistent with the rotation direction of the feed source, that is, the antenna to be tested rotates clockwise.

9. The compact field polarization calibration method according to claim 1, characterized in that: If the antenna to be tested is a linearly polarized antenna, the corrected amplitude pattern amV′_0 and phase pattern phV′_0 in (S6) are: amV′_0=amV_0-Δam phV′_0=phV_0-Δph The far-field amplitude pattern and phase pattern test results of the antenna to be tested are the amplitude pattern amV′_0 and the phase pattern phV′_0.

10. The compact field polarization calibration method according to claim 1, characterized in that: If the antenna to be tested is a circularly polarized antenna, the corrected amplitude pattern amV′_0 and phase pattern phV′_0 are calculated in (S6), and the far-field amplitude pattern amH_0 and phase pattern phH_0 of the first polarization first test obtained in (S2) are calculated to obtain the far-field amplitude pattern and phase pattern test results of the antenna to be tested: amV′_0=amV_0-Δam phV′_0=phV_0-Δph Where am_R is the amplitude of right-hand circular polarization after circular polarization synthesis, am_L is the amplitude of left-hand circular polarization after circular polarization synthesis, ph_R is the phase of right-hand circular polarization after circular polarization synthesis, ph_L is the phase of left-hand circular polarization after circular polarization synthesis, abs is the modulus operation of complex numbers, angle is the phase angle operation of complex numbers, and j is the symbol of the complex number j 2 =-1, π is the ratio of a circle to a circumference of ...

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