A kind of quick calibration of amplitude and phase method of phased array merely with amplitude measurementTechnical field
Field of the present invention is antenna measurement field, in the phased array antenna calibration test such as satellite communication and navigationIn have good applicability.
Background technique
It designing in phased array antenna with assembly, unit channel amplitude-phase consistency is relatively difficult to guarantee, especially phase equalization,It requires the signal transmission link in each channel the electrical length such as to be necessary for, this to design processing, Denso and matching requirements excessivelyIt is harsh, it is extremely difficult to realize.Therefore it is necessary to carry out calibration to channel initial amplitude and phase before antenna is delivered.
Phased array antenna channel calibration of amplitude and phase solves front unit channel width by measurement means and is mutually distributed.It is existing at presentMeasurement means there are two types of, one is the measurements of direct amplitude and phase, i.e., using near-field scan frame to the width in each channel of frontDegree and phase carry out independent measurement, and the equipment that this kind of mode needs is excessively complicated, and for massive phased array antenna, scanning supportScale is excessively huge；Another kind is amplitude measurement method, i.e., carries out front far field amplitude measurement in the case where different fronts are with phase state,It resolves each channel width using amplitude measurements to be mutually worth, this kind of mode is at present in order to meet solving condition, required amplitude measurementNumber is more, and calibration timeliness is bad, if channel phase shifters' digit is 5, then required amplitude is surveyed for N element arrayAmount number just needs 25N times.In addition this method needs to eliminate ambiguity in solution procedure, makes troubles to practical.
Summary of the invention
The present invention is based on aerial array far field amplitude measurements to provide a kind of quick calibration of amplitude and phase method of phased array antenna, shouldFront is grouped by method, is measured under different channel phases and switch state to front synthesis field amplitude, is then resolvedThe width of front is mutually distributed out.Amplitude measurement number in far field needed for this kind of method is only (3N+1) secondary, significantly improves calibration timelinessProperty, and required calibrator (-ter) unit amount is few, and calibration process is simple.
In order to solve the above technical problems, the method applied in the present invention are as follows:
A kind of quick calibration of amplitude and phase method of phased array merely with amplitude measurement, by 1 radio frequency mouth of phased array antenna to be measured withFrequency spectrograph 6 connects, and standard horn antenna 3 is placed in 1 far-field region of phased array antenna to be measured, guarantees phased array antenna 1 to be measuredIt is communicated with the foundation of standard horn antenna 3, standard horn antenna 3 is connect with signal source 7.
S1. it is grouped.Phased array antenna 1 to be measured includes N number of antenna element, and phased array antenna 1 to be measured is divided and is combined for N kind,Any one grouping k includes m phasing unit and n phase holding unit, wherein m+n=N.Kth kind is combined, it is wholeBattle array synthesis radiation field range value is expressed as
Pk=Ak12+Ak22+2Ak1Ak2cos(Φk1-Φk2-Δ)
Wherein Ak1Radiation field amplitude, Φ are synthesized for kth group phasing unitk1Spoke is synthesized for kth group phasing unitPenetrate the initial phase of field, Ak2Radiation field amplitude, Φ are synthesized for kth group phase holding unitk2For the conjunction of kth group phase holding unitAt the initial phase of radiation field, Δ is the channel amount of phase shift of phasing unit；
S2. above-mentioned A is solvedk1、Ak2And Φk1-Φk2。
1. recording initial state performance number.All channels of phased array antenna 1 to be measured are opened, the phase shifter in all channels is all setIn 0 state, the level value on frequency spectrograph 6 is recorded, P is denoted as0, the synthesis radiation field of the antenna array of phased array antenna 1 to be measured at this timePower is
P0=Ak12+Ak22+2Ak1Ak2cos(Φk1-Φk2)
Performance number when 2. the channel amount of phase shift for recording phasing unit is 90 °.90 ° are set by channel amount of phase shift Δ,Synthesis radiation field power is at this time
Pk1=Ak12+Ak22+2Ak1Ak2sin(Φk1-Φk2)
3. performance number when recording the shutdown of phase holding unit channel power source.The power switch that phase keeps channel is turned off, i.e.,Ak2≈ 0, synthesizing radiation field power at this time is Pk2≈Ak12
4. performance number then turns off the power switch in phase adjustment channel when record phasing unit channel power source shutdown,That is Ak1≈ 0, synthesizing radiation field power at this time is Pk3≈Ak22
5. solving Ak1、Ak2And Φk1-Φk2.1., 2., 3. and 4. by above-mentioned steps
Recorded in numerical value and formula carry out simultaneous and obtain
Above formula can further solve relative amplitude and phase of the phasing unit relative to full battle array synthesis radiation field in kth groupPosition
S3. width phase of the phasing unit synthesis radiation field relative to whole battle array global radiation field in the grouping of residue N-1 kind is solvedValue.Step S2 is repeated, the width phase of phasing unit synthesis radiation field whole battle array global radiation field relatively in remaining N-1 grouping is acquiredValue；
S4. compensation calibration width is asked mutually to be worth.The width of the relatively whole battle array resultant field of radiation field is synthesized by the N number of phasing unit acquiredMutually value can establish following matrix form
Wherein, MN×NTo choose N level matrix number；Column vectorIt is expressed as unitRadiation field is mutually worth relative to the width of whole battle array；Column vectorIt is expressed as having solved to obtainEvery group in phasing unit synthesis radiation field be mutually worth relative to the width of whole battle array；
Final radiation field of each element is mutually worth relative to the width of whole battle array resultant field to be expressed as
By what is solvedIt is handed down to phased array antenna 1 to be measured, calibration can be realized.
Further, it also needs to carry out following calculate in step sl.Phasing unit channel amount of phase shift is changed simultaneously,Amount of phase shift is set as Δ, and the synthesis radiation field of phasing unit is expressed as
Wherein, Ak1For phasing unit synthesis radiation field amplitude, Φ in kth groupk1For phasing unit in kth groupSynthesize the initial phase of radiation field.
The synthesis radiation field of phase holding unit is expressed as in the kth group of phased array antenna 1 to be measured
Wherein, Ak2For phase holding unit synthesis radiation field amplitude, Φ in kth groupk2For phase holding unit in kth groupSynthesize the initial phase of radiation field.
Phasing unit synthesizes the sum of radiation field and its conjugate multiplication with phase holding unit, and whole battle array synthesis can be obtainedRadiation field power expression
Pk=(Ek1+Ek2)·(Ek1+Ek2)*=Ak12+Ak22+2Ak1Ak2cos(Φk1-Φk2-Δ)。
The invention has the advantage that compared to background technique
1, only the amplitude of radiation field is measured, required calibrator (-ter) unit amount is small, and calibration process is simple；
2, required amplitude measurement number is that (3N+1) is secondary, improves phased array antenna calibration timeliness；
3, in channel width mutually solves, it is not related to equation ambiguity problem, simplifies calculating process.
Detailed description of the invention
Fig. 1 is phased array antenna calibration schematic diagram of the present invention.
Fig. 2 is 32 yuan of phased array antenna calibration grouping schematic diagrames.
Specific embodiment
Embodiment 1
Next by taking 32 yuan of phased array receiving antennas as an example, detailed description of the present invention calibration process.
Phased array antenna calibration scene is built shown in referring to Fig.1.Phased array antenna 1 to be measured is placed on test table 2；Standard horn antenna 3 is placed on the bracket 4 in 1 far-field region of phased array antenna to be measured, and guarantees the center etc. of two antennasIt is high；Test table 2 is adjusted by control host computer 5, so that the center of two antennas is aligned；By 1 radio frequency mouth of phased array antenna to be measuredIt is connect with frequency spectrograph 6, electromagnetic horn 3 is connect with signal source 7, antenna 1 to be measured and control host computer are connected by controlling cable5。
All channels of antenna 1 to be measured are opened by controlling host computer 5, and all channel phase shifters are placed in 0 state；Open frequencySpectrometer 6 and signal source 7, set calibration frequency.
When all channel phase shifters are in 0 state, the level value on frequency spectrograph 6 is recorded, P is denoted as0。
S1. it is grouped, referring to front packet mode shown in Fig. 2, front is divided into 32 kinds of combinations, every group includes 15 phasesAdjustment unit and 17 phase holding units.
For the 1st group, 90 ° are set by the channel amount of phase shift Δ of phasing unit, records the level on frequency spectrograph 6Value, is denoted as P11。
1. turning off the power switch (or RF switch) that phase keeps channel, the level value on frequency spectrograph 6 is recorded, is denoted asP12。
2. opening the power switch (or RF switch) that phase keeps channel, the power switch in phase adjustment channel is turned off(or RF switch) records the level value on frequency spectrograph 6, is denoted as P13。
Step 8, the P by measuring0、P11、P12And P13, lower right corner footmark symbol P11First group first is represented, it will be underGrouping label is replaced with K in formula,
The relative amplitude and phase that phasing unit in kth group synthesizes relative to full battle array field can further be solved by above formulaPosition.
And according to K at this time can be calculated by above-mentioned formula be 1, i.e., the opposite width phase of phasing unit synthesis field in the 1st groupValue.
S2. it solves phasing unit synthesis radiation field in packets remaining to be mutually worth relative to the width of whole battle array global radiation field, weightMultiple step S1, the opposite width that can calculate phasing unit synthesis field in other 31 groups are mutually worth.
S3. it asks compensation calibration width to be mutually worth, is mutually worth by the opposite width that counted phasing unit synthesizes field,
And according to formula
The opposite width that the relatively full battle array of each radiation field of each element can be calculated mutually is worth, wherein coefficient matrix M32×32It can be by Fig. 2 instituteShow that packet mode obtains, the first behavior [11×15 01×17], on the basis of the first row, row k is the first row cyclic shift to the right(k-1) secondary.
Mutually being worth by the opposite width of radiation field of each element can be obtained the compensation for calibrating errors width of each unit channel and is mutually worth, to complete battle arrayFace calibration.
Assuming that channel phase shifters' digit is 6, in above-mentioned steps, the required amplitude measurement number of the present invention is 3 × 32+1=97 times, and amplitude measurement number nearly 32 × 2 needed for existing electric rotating vector calibration method6=2048 times.Therefore this hairThe bright required amplitude measurement number of calibration that greatly reduces is, it can be achieved that front is quickly calibrated.
The comparison of table 1 the method for the present invention and electric rotating vector method
| Amplitude measurement number |
| The method of the present invention | 97 times |
| Existing electric rotating vector method | 2048 times |
Embodiment 2
S1. it is grouped, it is assumed that phased array antenna has N number of antenna element, carries out N kind different grouping to front.Any oneIt is grouped k and includes m phasing unit and n phase holding unit, wherein m+n=N.It can using phased array antenna channel phasesTune feature changes simultaneously phasing unit channel amount of phase shift, and amount of phase shift is set as Δ, and the synthesis field of phasing unit can indicateFor
Wherein Ak1Field amplitude, Φ are synthesized for kth group phasing unitk1The first of field is synthesized for kth group phasing unitBeginning phase.Similar, the synthesis field of kth group phase holding unit is represented by
After phase adjustment is added, whole battle array synthesis field power is represented by kth group in this way
Pk=(Ek1+Ek2)·(Ek1+Ek2)*=Ak12+Ak22+2Ak1Ak2cos(Φk1-Φk2-Δ) (3)
Field amplitude value is synthesized by measuring whole battle array under different channel phases and switch state, A can be calculatedk1、Ak2And Φk1-Φk2。
S2. above-mentioned A is solvedk1、Ak2And Φk1-Φk2,
0 ° is set by channel amount of phase shift Δ first, i.e., the initial state of whole battle array, the initial state of all groupings is all the same, synthesisField power are as follows:
P0=Ak12+Ak22+2Ak1Ak2cos(Φk1-Φk2) (4)
Secondly 90 ° are set by channel amount of phase shift Δ, synthesizing field power at this time is
Pk1=Ak12+Ak22+2Ak1Ak2sin(Φk1-Φk2) (5)
It is then powered off the power switch that phase keeps channel, i.e. Ak2≈ 0, synthesizing field power at this time is Pk2≈Ak12 (6)
Then the power switch in phase adjustment channel, i.e. A are turned offk1≈ 0, synthesizing field power at this time is Pk3≈Ak22 (7)
Formula (6) and formula (7) are substituted into formula (4) and formula (5), can be solved
2Ak1Ak2cos(Φk1-Φk2)=P0-Pk2-Pk3 (8)
2Ak1Ak2sin(Φk1-Φk2)=Pk1-Pk2-Pk3 (9)
Joint type (6-9) can solve
The relative amplitude and phase that phasing unit in kth group synthesizes relative to full battle array field can further be solved by above formulaPosition.
S3. phasing unit in the grouping of residue N-1 kind is successively solved according to the method described above synthesizes radiation field relative to wholeThe width of battle array global radiation field is mutually worth, and repeating the above steps in this way can the following equation group of simultaneous:
In formula, MN×NIt for N level matrix number, is made of 1 and 0, every a line represents a kind of packet mode, wherein in 1 expression groupPhasing unit, phase holding unit in 0 expression group；VectorMiddle element is unitRadiation field is mutually worth relative to the width of full battle array；VectorMiddle element be solved it is everyPhasing unit is mutually worth relative to the width of full battle array in group.
S4. compensation calibration width is asked mutually to be worth, by being rationally grouped, so that matrix MN×NIt is reversible.Hadamard square can be used in the matrixThe matrix form of cyclic shift composition can also be used in formation formula.Such as 8 rank matrix M8×8, as shown in formula (13), the first rowFor [1,1,1,1,1,0,0,0], on the basis of the first row, second the first row element of behavior cyclic shift 1 time to the right, the 3rd behaviorCyclic shift 2 times to the right of first row element, successively can be obtained other row elements；For 12 rank matrix M12×12, the first behavior [1,1,1,1,1,1,1,0,0,0,0,0], according to above-mentioned rule, circuiting sequentially displacement can be obtained matrix M12×12, as shown in formula (14).
It is mutually distributed by the width that formula (12) can solve front:
The calibration of amplitude and phase value of unit channel can be obtained by formula (15), to realize phased array antenna calibration.In calibration processIn, every kind of grouping needs under different channel phases and switch state measurement synthesis field amplitude 3 times, needs 3N measurement altogether；In addition1 front initial state amplitude measurement is further related to, therefore required amplitude measurement of the invention is that (3N+1) is secondary.
S3, embodiment 3
A kind of quick calibration of amplitude and phase method of phased array merely with amplitude measurement, by 1 radio frequency mouth of phased array antenna to be measured withFrequency spectrograph 6 connects, and standard horn antenna 3 is placed in 1 far-field region of phased array antenna to be measured, guarantees phased array antenna 1 to be measuredIt being communicated with the foundation of standard horn antenna 3, standard horn antenna 3 is connect with signal source 7,
S1. it being grouped, phased array antenna 1 to be measured includes N number of antenna element, and phased array antenna 1 to be measured is divided and is combined for N kind,Any one grouping k includes m phasing unit and n phase holding unit, wherein m+n=N.
Phasing unit channel amount of phase shift is changed simultaneously, amount of phase shift is set as Δ, the synthesis radiation field of phasing unitIt is expressed as
Wherein, Ak1For phasing unit synthesis radiation field amplitude, Φ in kth groupk1For phasing unit in kth groupSynthesize the initial phase of radiation field.
The synthesis radiation field of phase holding unit is expressed as in the kth group of phased array antenna 1 to be measured
Wherein, Ak2For phase holding unit synthesis radiation field amplitude, Φ in kth groupk2For phase holding unit in kth groupSynthesize the initial phase of radiation field.
Phasing unit synthesizes the sum of radiation field and its conjugate multiplication with phase holding unit, and whole battle array synthesis can be obtainedRadiation field power expression
Pk=(Ek1+Ek2)·(Ek1+Ek2)*=Ak12+Ak22+2Ak1Ak2cos(Φk1-Φk2-Δ)。
Kth kind is combined, whole battle array synthesis radiation field range value is expressed as
Pk=Ak12+Ak22+2Ak1Ak2cos(Φk1-Φk2-Δ)
Wherein Ak1Radiation field amplitude, Φ are synthesized for kth group phasing unitk1Spoke is synthesized for kth group phasing unitPenetrate the initial phase of field, Ak2Radiation field amplitude, Φ are synthesized for kth group phase holding unitk2For the conjunction of kth group phase holding unitAt the initial phase of radiation field, Δ is the channel amount of phase shift of phasing unit；
S2. above-mentioned A is solvedk1、Ak2And Φk1-Φk2,
6. recording initial state performance number, all channels of phased array antenna 1 to be measured are opened, the phase shifter in all channels is all setIn 0 state, the level value on frequency spectrograph 6 is recorded, P is denoted as0, the synthesis radiation field of the antenna array of phased array antenna 1 to be measured at this timePower is
P0=Ak12+Ak22+2Ak1Ak2cos(Φk1-Φk2)
Performance number when 7. the channel amount of phase shift for recording phasing unit is 90 °.90 ° are set by channel amount of phase shift Δ,Synthesis radiation field power is at this time
Pk1=Ak12+Ak22+2Ak1Ak2sin(Φk1-Φk2)
8. performance number when recording the shutdown of phase holding unit channel power source.The power switch that phase keeps channel is turned off, i.e.,Ak2≈ 0, synthesizing radiation field power at this time is Pk2≈Ak12
9. performance number then turns off the power switch in phase adjustment channel when record phasing unit channel power source shutdown,That is Ak1≈ 0, synthesizing radiation field power at this time is Pk3≈Ak22
10. solving Ak1、Ak2And Φk1-Φk2.By above-mentioned steps 1., 2., 3. and 4. recorded in numerical value and formula intoRow simultaneous obtains
Above formula can further solve relative amplitude and phase of the phasing unit relative to full battle array synthesis radiation field in kth groupPosition
S3. width phase of the phasing unit synthesis radiation field relative to whole battle array global radiation field in the grouping of residue N-1 kind is solvedValue repeats step S2, acquires the width phase of phasing unit synthesis radiation field whole battle array global radiation field relatively in remaining N-1 groupingValue；
S4. it asks compensation calibration width to be mutually worth, the width of the relatively whole battle array resultant field of radiation field is synthesized by the N number of phasing unit acquiredMutually value can establish following matrix form
Wherein, MN×NTo choose N level matrix number；Column vectorIt is expressed as unitRadiation field is mutually worth relative to the width of whole battle array；Column vectorIt is expressed as having solved to obtainEvery group in phasing unit synthesis radiation field be mutually worth relative to the width of whole battle array；
Final radiation field of each element is mutually worth relative to the width of whole battle array resultant field to be expressed as
By what is solvedIt is handed down to phased array antenna 1 to be measured, calibration can be realized.