CN106199220A - Array antenna phase equalization measuring method based on optical path difference correction - Google Patents

Abstract

Array antenna phase equalization measuring method based on optical path difference correction, relates to antenna measurement.Comprise the following steps: 1) build Antenna testing system, array antenna to be measured need to be in same level with launching antenna；2) test each antenna element, obtain the phase pattern test data that each unit is original；3) utilize optical path difference updating formula that the phase pattern test data that each unit is original are carried out optical path difference correction, the phase pattern corrected for the first time；4) optical path difference correcting algorithm is utilized to obtain parameter d during the root-mean-square error minimum of array antenna phase place global consistency₀, Δ and θ₀Value；5) phase pattern after each unit corrected parameter and the phase place root-mean-square error of each unit are calculated.It is not necessary for directly measuring in the case of each element antenna moves array position the phase pattern of multiple element antennas.Measurement error had good inhibiting effect.Have and well correct performance.

Description

Array antenna phase equalization measuring method based on optical path difference correction

Technical field

The present invention relates to antenna measurement, be specifically related to a kind of array antenna phase equalization based on optical path difference correction and survey Metering method.

Background technology

The concordance of element antenna phase place is to weigh the key technical indexes [1] of the array antennas such as direction finding interferometer.Interfere The principle of instrument direction finding be the phase difference value utilizing antenna element to receive to calculate arrival bearing [2], so element antenna phase place Concordance the direction finding precision of direction finding interferometer is had vital effect.In order to ensure unit sky in different directions The phase equalization of line, it usually needs the phase pattern of element antenna is measured.

The measurement of antenna phase pattern and the phase center of antenna closely bound up [3], be currently used for detecting antenna phase The method at center is fewer, only for the analytic process [4] of simple antenna, method based on flat scanning [5] etc..Traditional phase The measuring method of position directional diagram needs to be accurately placed in antenna phase center the center [6] of measuring circurmarotate, to array antenna Speech, this method is required to move the position of array, so that the phase center of to-be-measured cell to the greatest extent may be used when measuring each unit Can be positioned on turntable center, this operation is the most loaded down with trivial details, and for away from the unit of array center, array center of gravity is remote The problems such as the difficulty that can cause antenna installation from turntable and the polarization mismatch not occurred at horizontal plane, and actually unit sky The phase center of line is not usually the most knowable, and the uncertainty of the phase center of element antenna can make the phase place measured Directional diagram contains bigger error.

Phase equalization bearing calibration about array antenna in recent years has invents as follows:

Chinese patent 01112987.5 discloses a kind of intelligent antenna channel array correcting method and device [8], by than Compared with signal known to a parameter by the forward and backward amplitude of each passage to be corrected and phase characteristic, calculate passage to be corrected Amplitude and phase characteristic, treat correction channel on this basis and carry out amplitude and phase compensation so that after correction each lead to The amplitude in road is consistent with phase characteristic.

Chinese patent 201210415102.0 discloses width phase one between a kind of external illuminators-based radar array antenna echo channel The bearing calibration [9] of cause property, directly utilizing emitter Signals is corrected echo reception array antenna, by echo antenna alignment Radiation source, arranges Basic wave passage, is mixed with Basic wave channel signal by remaining each echo channel signal, calculates it Remaining echo channel, relative to the correction coefficient of Basic wave passage, closes after each echo channel signal is finally multiplied by correction coefficient Become echo-signal.

Said method needs special corrective network in operation, and operation is complicated, and due to merit subnetting in corrective network The error of the equipment such as network, can introduce new phase equalization error.

List of references:

[1] Stephen E.Linpsky writes, Gong Jin shoe last or hat block, and Zhang Dewen, Li Zhen are elementary to be translated, microwave passive direction finding [M], and 1993.

[2] Xiao Xiuli. interferometer direction finding principle [J]. China radio .2006 (05)

[3]Schmid R,Rothacher M,Thaller D,et al.Absolute phase center corrections of satellite and receiver antennas[J].GPS solutions,2005,9(4): 283-293.

[4]Wang Y G,Wang J,Zhao Z Q,et al.A novel method to calculate the phase center of antennas[J].Journal of Electromagnetic Waves and Applications,2008,22(2-3):239-250.

[5]Padilla P,Pousi P,Tamminen A,et al.Experimental determination of DRW antenna phase center at mm-wavelengths using a planar scanner:Comparison of different methods[J].Antennas and Propagation,IEEE Transactions on,2011,59 (8):2806-2812.

[6] Dong Shuyi. microwave measurement [M]. National Defense Industry Press, 1985.

[7]Beeckman P A.Analysis of phase errors in antenna-measurements applications to phase-pattern corrections and phase-centre determination[C]// IEE Proceedings H.Microwaves,Antennas and Propagation.1985,132:391-4.

[8] Guo Junfeng etc. intelligent antenna channel array correcting method and device: China, 01112987.5 [P] .2003- 01-01.

[9] Dan Tao etc. the bearing calibration of amplitude-phase consistency between a kind of external illuminators-based radar array antenna echo channel: in State, 201210415102.0 [P] .2013-01-23.

Summary of the invention

The test difficulty brought because of antenna pattern when present invention aim to address measuring unit antenna radiation pattern concordance, Offer is not necessary for each element antenna and moves array position, can directly measure the one of multiple element antenna based on optical path difference The array antenna phase equalization measuring method of correction.

The present invention comprises the following steps:

1) building Antenna testing system, array antenna to be measured need to be in same level with launching antenna；

2) test each antenna element, obtain the phase pattern test data that each unit is original；

3) utilize optical path difference updating formula that the phase pattern test data that each unit is original are carried out optical path difference correction, Phase pattern to first correction；

4) optical path difference correcting algorithm is utilized to obtain parameter during the root-mean-square error minimum of array antenna phase place global consistency d₀, Δ and θ₀Value；

5) phase pattern after each unit corrected parameter and the phase place root-mean-square error of each unit are calculated.

In step 3) in, described optical path difference updating formula is:

${\mathrm{\φ}}_i^c\left(\mathrm{\θ}\right)={\mathrm{\φ}}_i\left(\mathrm{\θ}\right)+2\mathrm{\π}\left(L_i^c\right(\mathrm{\θ})-L_0)/\mathrm{\λ}$

Wherein:For testing the antenna actual range to i-th unit,For i-th unit boost line subpoint to test antenna distance；

φ_i(θ): the phase response test data of i-th unit；

Phase response after the correction of i-th unit light path difference；

The anglec of rotation of θ: array antenna；

λ: the electric wave wavelength that test uses；

L₀: launch antenna and the distance of turntable center；

d_i: the position (order from left to right) of i-th unit (phase center)；

d₀: the position that the vertical line of turntable center to array intersects with array；

Δ: the distance of the made vertical line of turntable center to array.

In step 4) in, the root-mean-square error of described array antenna phase place global consistency is:

${\mathrm{RMS}}^{\mathrm{\φ}}=\sqrt{\frac{\underset{i=1}{\overset{M}{\Σ}}\left|\right|{\mathrm{\φ}}_i^c\left(\mathrm{\θ}\right)-{\stackrel{\‾}{\mathrm{\φ}}}_i^c\left(\mathrm{\θ}\right)|{|}_2^2}{MN}}$

Wherein,Representing the average phase response after each unit phasing, N represents Pattern measurement The length of data, M represents unit number, | | | |₂Represent 2 norms, i=1,2 ..., M.

In step 4) in, the root-mean-square error minimum criteria of described array antenna phase place global consistency is:

$\{{\hat{d}}_0,\widehat{\mathrm{\Δ}},{\widehat{\mathrm{\θ}}}_0\}=\underset{d_0,\mathrm{\Δ},{\mathrm{\θ}}_0}{min}\sqrt{\frac{\underset{i=1}{\overset{M}{\Σ}}\left|\right|{\mathrm{\φ}}_i^c\left(\mathrm{\θ}\right)-{\stackrel{\‾}{\mathrm{\φ}}}_i^c\left(\mathrm{\θ}\right)|{|}_2^2}{MN}}$

Wherein, θ=θ₀+θ_r, θ₀For the initial value of θ, θ_rThe turntable anglec of rotation for record.

In step 5) in, the phase place root-mean-square error of described each unit is calculated by following formula:

${\mathrm{RMS}}_i^{\mathrm{\φ}}=\frac{\left|\right|{\mathrm{\φ}}_i^c\left(\mathrm{\θ}\right)-{\stackrel{\‾}{\mathrm{\φ}}}_i^c\left(\mathrm{\θ}\right)|{|}_2}{\sqrt{N}}.$

The present invention proposes a kind of directly to survey in the case of not using special corrective network, not moving array antenna Measure the phase pattern of multiple element antenna, and appearance during array antenna phase equalization is measured can be reduced by optical path difference correction The method of error.

The present invention propose a kind of be not necessary for directly measuring in the case of each element antenna moves array position many The method of the phase pattern of individual element antenna.The present invention proposes antenna phase center optical path difference school not when turntable center Positive formula, gives the minimum mean square error criterion of array antenna phase equalization, has developed a kind of new optical path difference correction and has calculated Method, this algorithm make use of the spatial structural form that array element is distributed, it is possible to uses the phase response of all array elements to survey Amount data, have good inhibiting effect to measurement error.The result of linear array measured data is proved that the present invention carries The optical path difference correcting algorithm gone out has and well corrects performance.

Accompanying drawing explanation

Fig. 1 is the antenna measurement view of the present invention；

Fig. 2 is the phase pattern that certain non-uniform spacing array of the present invention is original；

Fig. 3 is the phase pattern in the present invention after certain non-uniform spacing array employing optical path difference correction；

Fig. 4 is the phase pattern that certain uniform intervals array of the present invention is original；

Fig. 5 is the phase pattern in the present invention after certain uniform intervals array employing optical path difference correction.

Detailed description of the invention

With embodiment, the present invention is described in further detail below in conjunction with the accompanying drawings.

The embodiment of the present invention comprises the following steps:

1) building Antenna testing system according to Fig. 1, array antenna to be measured need to be in same level with launching antenna；

2) test each antenna element, obtain the phase pattern test data that each unit is original；

3) utilize optical path difference updating formula that the phase pattern test data that each unit is original are carried out optical path difference correction, Phase pattern to first correction；

The optical path difference updating formula of i-th unit is:

${\mathrm{\φ}}_i^c\left(\mathrm{\θ}\right)={\mathrm{\φ}}_i\left(\mathrm{\θ}\right)+2\mathrm{\π}\left(L_i^c\right(\mathrm{\θ})-L_0)/\mathrm{\λ}---\left(1\right)$

Wherein,For testing the antenna actual range to i-th unit,For i-th unit boost line subpoint to test antenna distance；

φ_i(θ): the phase response test data of i-th unit；

Phase response after the correction of i-th unit light path difference；

The anglec of rotation of θ: array antenna；

λ: the electric wave wavelength that test uses；

L₀: launch antenna and the distance of turntable center；

d_i: the position (order from left to right) of i-th unit (phase center)；

d₀: the position that the vertical line of turntable center to array intersects with array；

Δ: the distance of the made vertical line of turntable center to array；

4) optical path difference correcting algorithm is utilized to obtain parameter d during the root-mean-square error minimum of phase place global consistency₀, Δ and θ₀ Value；The root-mean-square error of array antenna phase place global consistency is calculated by formula (2):

${\mathrm{RMS}}^{\mathrm{\φ}}=\sqrt{\frac{\underset{i=1}{\overset{M}{\Σ}}\left|\right|{\mathrm{\φ}}_i^c\left(\mathrm{\θ}\right)-{\stackrel{\‾}{\mathrm{\φ}}}_i^c\left(\mathrm{\θ}\right)|{|}_2^2}{MN}}---\left(3\right)$

Wherein,Represent the average phase response after each unit phasing, | | | |₂Represent 2 models Number, N represents the length of Pattern measurement data, and M represents unit number, i=1,2 ..., M；

Carry out optical path difference timing, need the parameter accurately measured to have d₀, Δ and initial value θ at θ angle₀.Wherein θ=θ₀+ θ_r, θ_rThe turntable anglec of rotation for record.In actual experiment with measuring, it is difficult to obtain the precise measurements of these parameters.The present invention The first measured value of above-mentioned parameter is adjusted, estimates with the minimum criterion of root-mean-square error of array antenna phase place global consistency Parameter d₀, Δ and θ optimum, i.e.

$\{{\hat{d}}_0,\widehat{\mathrm{\Δ}},{\widehat{\mathrm{\θ}}}_0\}=\underset{d_0,\mathrm{\Δ},{\mathrm{\θ}}_0}{min}\sqrt{\frac{\underset{i=1}{\overset{M}{\Σ}}\left|\right|{\mathrm{\φ}}_i^c\left(\mathrm{\θ}\right)-{\stackrel{\‾}{\mathrm{\φ}}}_i^c\left(\mathrm{\θ}\right)|{|}_2^2}{MN}}---\left(4\right)$

Step 5: calculate the phase pattern after each unit corrected parameter and phase place root-mean-square error.

Phase pattern after using optical path difference updating formula (1) to calculate each unit parameters revision, is the present invention and passes through The unit phase pattern of the final gained of optical path difference correcting algorithm.

The phase place root-mean-square error of i-th unit is calculated by following formula

${\mathrm{RMS}}_i^{\mathrm{\φ}}=\frac{\left|\right|{\mathrm{\φ}}_i^c\left(\mathrm{\θ}\right)-{\stackrel{\‾}{\mathrm{\φ}}}_i^c\left(\mathrm{\θ}\right)|{|}_2}{\sqrt{N}}---\left(5\right)$

Specific embodiment given below:

Step 1: build Antenna testing system, the antenna measurement view of the present invention is as it is shown in figure 1, battle array the most to be measured Array antenna is in same level with launching antenna.Array to be measured has four identical antenna elements, interval to be respectively 0.426m, 0.142m, 0.217m, the distance of transmitting antenna to test table center is 9m, and frequency test signal is 1.6GHz.

Step 2: test each antenna element, obtains the original phase Pattern measurement data of each unit.

The phase pattern test data of four antenna elements are as shown in Figure 2.The phase pattern test data of each unit Show inconsistent result.

Step 3: utilize optical path difference updating formula that the phase pattern test data that each unit is original are carried out optical path difference school Just, the phase pattern corrected for the first time；

Step 4: utilize optical path difference correcting algorithm to obtain parameter d during the root-mean-square error minimum of phase place global consistency₀、Δ And θ₀Value；

Step 5: calculate the phase pattern after each unit corrected parameter and phase place root-mean-square error.

Phase pattern after processing the phase pattern of four unit with optical path difference correcting algorithm is as it is shown on figure 3, each The phase directional diagram data after unit correction root-mean-square statistic bias result in the range of ± 49 ° is given by table 1.

Table 1

Antenna	Antenna 1	Antenna 2	Antenna 3	Antenna 4
					Nonuniform Linear Array	5.9°	15.6°	8.6°	18.7°
Even linear array	5.8°	5.9°	4.7°	2.4°

Processing certain uniform intervals linear array in the same way, this linear array has four identical antenna elements, is spaced apart 0.07m, the distance of transmitting antenna to test table center is 8.8m, and frequency test signal is 1.6GHz.The test original phase of gained Position response directional diagram as shown in Figure 4, its optical path difference correction after phase pattern as it is shown in figure 5, each unit correction after phase place Pattern data root-mean-square statistic bias result in the range of ± 49 ° is given by table 1.

Further the phase pattern after each unit correction in the present invention and original phase pattern test data are entered Row compares, it is seen that each unit phase pattern after correction has good concordance, the phase place root-mean-square after each unit correction Error also demonstrates method proposed by the invention can the impact of random noise in the least each unit test process.

Claims (5)

1. array antenna phase equalization measuring method based on optical path difference correction, it is characterised in that comprise the following steps:

1) building Antenna testing system, array antenna to be measured need to be in same level with launching antenna；

2) test each antenna element, obtain the phase pattern test data that each unit is original；

3) utilize optical path difference updating formula that the phase pattern test data that each unit is original are carried out optical path difference correction, at the beginning of obtaining The phase pattern of secondary correction；

4) optical path difference correcting algorithm is utilized to obtain parameter d during the root-mean-square error minimum of array antenna phase place global consistency₀、Δ And θ₀Value；

5) phase pattern after each unit corrected parameter and the phase place root-mean-square error of each unit are calculated.

2. the array antenna phase equalization measuring method corrected based on optical path difference as claimed in claim 1, it is characterised in that Step 3) in, described optical path difference updating formula is:

${\mathrm{\φ}}_i^c\left(\mathrm{\θ}\right)={\mathrm{\φ}}_i\left(\mathrm{\θ}\right)+2\mathrm{\π}\left(L_i^c\right(\mathrm{\θ})-L_0)/\mathrm{\λ}$

Wherein:For testing the antenna actual range to i-th unit,For i-th unit boost line subpoint to test antenna away from From；

φ_i(θ): the phase response test data of i-th unit；

Phase response after the correction of i-th unit light path difference；

The anglec of rotation of θ: array antenna；

λ: the electric wave wavelength that test uses；

L₀: launch antenna and the distance of turntable center；

d_i: the position (order from left to right) of i-th unit (phase center)；

d₀: the position that the vertical line of turntable center to array intersects with array；

Δ: the distance of the made vertical line of turntable center to array.

3. the array antenna phase equalization measuring method corrected based on optical path difference as claimed in claim 1, it is characterised in that Step 4) in, the root-mean-square error of described array antenna phase place global consistency is:

${\mathrm{RMS}}^{\mathrm{\φ}}=\sqrt{\frac{\underset{i=1}{\overset{M}{\Σ}}\left|\right|{\mathrm{\φ}}_i^c\left(\mathrm{\θ}\right)-{\stackrel{\‾}{\mathrm{\φ}}}_i^c\left(\mathrm{\θ}\right)|{|}_2^2}{MN}}$

Wherein,Representing the average phase response after each unit phasing, N represents Pattern measurement data Length, M represents unit number, | | | |₂Represent 2 norms, i=1,2 ..., M.

4. the array antenna phase equalization measuring method corrected based on optical path difference as claimed in claim 1, it is characterised in that Step 4) in, the root-mean-square error minimum criteria of described array antenna phase place global consistency is:

$\{{\hat{d}}_0,\widehat{\mathrm{\Δ}},{\widehat{\mathrm{\θ}}}_0\}=\underset{d_0,\mathrm{\Δ},{\mathrm{\θ}}_0}{min}\sqrt{\frac{\underset{i=1}{\overset{M}{\Σ}}\left|\right|{\mathrm{\φ}}_i^c\left(\mathrm{\θ}\right)-{\stackrel{\‾}{\mathrm{\φ}}}_i^c\left(\mathrm{\θ}\right)|{|}_2^2}{MN}}$

Wherein, θ=θ₀+θ_r, θ₀For the initial value of θ, θ_rThe turntable anglec of rotation for record.

5. the array antenna phase equalization measuring method corrected based on optical path difference as claimed in claim 1, it is characterised in that Step 5) in, the phase place root-mean-square error of described each unit is calculated by following formula:

${\mathrm{RMS}}_i^{\mathrm{\φ}}=\frac{\left|\right|{\mathrm{\φ}}_i^c\left(\mathrm{\θ}\right)-{\stackrel{\‾}{\mathrm{\φ}}}_i^c\left(\mathrm{\θ}\right)|{|}_2}{\sqrt{N}}.$