CN105044644A - Calibration standard selecting method aiming at vector network analyzer electronic calibration member - Google Patents

Abstract

The invention discloses a calibration standard selecting method aiming at a vector network analyzer electronic calibration member, comprising steps of converting a scaling value of an electronic standard member to a numerical value on a Smith circular image, utilizing an equation to solve the correlated value r (i,j) between scaling values of various standards, combining all correlated parameters into an array R, setting a correlated tolerance threshold z, utilizing a selection standard to choose a standard combination, marking a selected standard combination in an electronic calibration member firmware program, choosing the marked standard to perform measurement and solving the single port error in the process of utilizing the electronic calibration member to calibrate, utilizing the single port error system error and combining with the through connection measurement data to obtain transmission tracking and load matching errors. The invention obtains the correlated array through the standard measurement calculation of the standard member and utilizing the correlation of the scaling standard of the electronic calibration member, obtains the standard with weak correlation according to the threshold value, effectively prevents the phenomenon of standard collision and improves the speed and accuracy of the calibration.

Description

For the calibration criterion choosing method of vector network analyzer Electronic Calibration part

Technical field

The present invention relates to vector network analysis field, especially a kind of calibration criterion choosing method for vector network analyzer Electronic Calibration part.

Background technology

The various impedance states of vector network analyzer Electronic Calibration part are determined jointly by transmission line, electronic switch and electronic standard.Owing to there being the interconnected of multiple device in signalling channel, there is multiple point of discontinuity.The existence of these point of discontinuity can bring impact to the parameter controlling various impedance state, and make the accurate model setting up electronic standard become very difficult, the multipath reflection brought can make, between the actual S parameter of electronic standard and design load, substantial deviation occurs.Add the impact of the uncertain factors such as microcomponent assembling, cause the Electronic Calibration part standard room of producing to have the phenomenon of " rule violations ".

Vector network analyzer is by after the calibration of Electronic Calibration part, and the error of vector network analyzer is quantized by the calibration value of each standard and measured value, and Here it is, and port error coefficient solves.Can provide the advantage of multiple standards according to Electronic Calibration, using Changeable weight Electronic Calibration algorithm to solve over-determined systems can to raising error coefficient solving precision.

Error coefficient solution procedure is:

A, each port carry out weighted least-squares method solve, obtain the reflection error coefficient entry that each port is corresponding.

Ten binomial error models are used to solve corresponding transmission error coefficient entry between b, every two ports.

Transmission error item between two-port is solved to common linear equation and solves.And the employing of single port reflection error coefficient is that overdetermined equation least square solves.Error coefficient directivity, source coupling, skin tracking are respectively by E _dF, E _sF, E _rFrepresent, Γ _mrepresent the measured value of electronic standard, Γ represents the scaled values of electronic standard.Error model establishes the relation between error coefficient item, to be measured actual value, to be measured test value, as shown in Figure 1.

Can obtain from error model:

Γ _m＝E _DF-(E _DFE _SF-E _RF)Γ+E _SFΓ _mΓ(1)

For the calibration of Electronic Calibration part, its calibration module is made up of cmos switch, provides the reflection electronic standard needed for calibration and straight-through electronic standard.Schematic diagram is shown in Fig. 2, and 8 control signals are used for selecting calibration criterion, thus complete calibration.

Utilize (as port one) on the calibration module single port shown in Fig. 2 can form 8 electronic standard impedance states, the standard value of its correspondence is Γ ₁, Γ ₂, Γ ₃, Γ ₄, Γ ₅, Γ ₆, Γ ₇, Γ ₈.The determination of standard value obtains by using highly sophisticated device calibration.Measured value in calibration process is Γ _m1, Γ _m2, Γ _m3, Γ _m4, Γ _m5, Γ _m6, Γ _m7, Γ _m8.

For 8 electronic standard impedance states that above-mentioned Electronic Calibration part provides, obtain system of equations matrix representation:

$\left[\begin{array}{ccc}1& {\mathrm{\Γ}}_1{\mathrm{\Γ}}_{m1}& -{\mathrm{\Γ}}_1\\ 1& {\mathrm{\Γ}}_2{\mathrm{\Γ}}_{m2}& -{\mathrm{\Γ}}_2\\ 1& {\mathrm{\Γ}}_3{\mathrm{\Γ}}_{m3}& -{\mathrm{\Γ}}_3\\ ...& ...& ...\\ 1& {\mathrm{\Γ}}_8{\mathrm{\Γ}}_{m8}& -{\mathrm{\Γ}}_8\end{array}\right]\left[\begin{array}{c}{E}_{DF}\\ E_{SF}\\ E_{DF}{E}_{SF}-E_{RF}\end{array}\right]=\left[\begin{array}{c}{\mathrm{\Γ}}_{m1}\\ {\mathrm{\Γ}}_{m2}\\ {\mathrm{\Γ}}_{m3}\\ ...\\ {\mathrm{\Γ}}_{m8}\end{array}\right]---\left(2\right)$

Be simplified shown as:

A×x＝b(3)

When utilizing least square solving equation, if there is ill-condition matrix, without solution or will there is false solution in equation.And Electronic Calibration part can not show a candle to mechanical standard parts index as the standard index that MMIC realizes, but this does not hinder these MMIC impedance states to be called a kind of Electronic Calibration standard, because Electronic Calibration uses based on the calibration mode of data file and the multi-mode error coefficient derivation algorithm of many standards, use these standards equally can carry out accurate error coefficient to solve, but have three basic requirements to this standard:

1. standard state curve can not have catastrophe point to exist, avoid error coefficient solve can not be correct in calculating carry out interpolation calculation.

2. the impedance state of each standard of each Frequency point can distribute and scatter on the former figure of Smith, namely each electronic standard impedance state will have independence, to ensure in error coefficient solution procedure that listed system of equations is non-ill-condition matrix like this, reduce the solving precision of error coefficient.

3. the impedance state of standard will have stability, can keep stable, avoid scale operation frequently within the longer time.

As can be seen from Figure 3, along with the rising of frequency, near 40GHz, the impedance curve of each standard is screwed in together gradually, and the phenomenon that this impedance state reaches unanimity can not ensure the independence of electronic standard.Thus when can not ensure that least square solves, there is not morbid state in equation (3).

Also have for temperature controlled circuit in module in addition.Module-external also needs to assemble corresponding microwave module joint.

That is, the identical standard scaled values after different Electronic Calibration part assembling is distinguishing.This inconsistency also result in equation (3) when solving, and does not determine the calibrating device characteristic of whole batch by the characteristic of certain calibrating device.

Existing Electronic Calibration part raising index in, mainly by methods such as detailed MMIC design, strict flow technique, high-precision connector designs.Algorithmically mainly on original least square basis, be weighted process to improve calibration accuracy.

Improve Electronic Calibration part calibration accuracy basic from the improvement of technique, design aspect.But existing technique and design proposal are fixed, the limited allowance of raising.

When being improved calibration accuracy by weighted least require method, the characteristic according to calibrating device standard is needed to carry out the setting of weights.Because a calibrating device batch consistance is difficult to ensure, can not carry out weight computing to certain Electronic Calibration part, be then applied in the calibration calculations of whole calibrating device, namely productibility is poor.

Summary of the invention

In order to solve the deficiencies in the prior art, the present invention proposes a kind of calibration criterion choosing method for vector network analyzer Electronic Calibration part.

The present invention adopts following technical scheme:

For the calibration criterion choosing method of vector network analyzer Electronic Calibration part, it is characterized in that, described calibration criterion choosing method adopts following steps:

Step 1, by the numerical value that the scaled values of Electronic Calibration part is converted on Smith chart, the scaled values number of Electronic Calibration part is n;

Step 2, utilizes Solving Equations to solve correlation values r (i, j) between various criterion scaled values;

Step 3, forms matrix R by all relevance parameter obtained in step 2;

Step 4, the relevant tolerance threshold value z (0<z<1) of setting;

Step 5, utilizes selection standard to carry out selection standard combination;

Step 6, in Electronic Calibration part firmware program, the standard combination that markers step 5 is chosen;

Step 7, when utilizing Electronic Calibration part to calibrate, the standard of selected marker is carried out measuring and is carried out solving of single port error;

Step 8, utilizes single port systematic error, obtains transmission tracking, load matched error in conjunction with straight-through measurement data.

Following Solving Equations is utilized to solve correlation values between various criterion scaled values in described step 2:

$r(i,j)=\frac{\underset{t=1}{\overset{p}{\mathrm{\&Sigma;}}}({\mathrm{\&Gamma;}}_{it}-\stackrel{\&OverBar;}{{\mathrm{\&Gamma;}}_i})({\mathrm{\&Gamma;}}_{jt}-\stackrel{\&OverBar;}{{\mathrm{\&Gamma;}}_j})}{\sqrt{\underset{t=1}{\overset{p}{\mathrm{\&Sigma;}}}{({\mathrm{\&Gamma;}}_{it}-\stackrel{\&OverBar;}{{\mathrm{\&Gamma;}}_i})}^2\underset{t=1}{\overset{p}{\mathrm{\&Sigma;}}}{({\mathrm{\&Gamma;}}_{jt}-\stackrel{\&OverBar;}{{\mathrm{\&Gamma;}}_j})}^2}}$

Wherein: t is scaling point, p is scaling point sum, Γ _itbe the scaled values of i-th standard on scaling point t, be the mean value of i-th all scaled values of standard, r (i, j) represents the correlativity of i-th standard and a jth standard, and r (i, j)=r (j, i).

In described step 3, matrix R is:

$R=\left[\begin{array}{cccc}r(1,1)& r(1,2)& ...& r(1,n)\\ r(2,1)& r(2,2)& ...& ...\\ ...& ...& ...& ...\\ r(n,1)& r(n,2)& ...& r(n,n)\end{array}\right].$

Utilize selection standard to carry out selection standard combination in described step 5 and adopt following steps:

A, the criterion numeral chosen are v, make v=n;

If B v≤3, then there is no satisfactory combination, exit computing;

If v > 3, in n standard, choose v standard (always have individual combination), obtain correlation matrix for each combination by step 3, and be denoted as to R _v1matrix element ask modulus value, then element is cumulative obtains in like manner matrix calculate from in find minimum value, be denoted as

C, right the threshold requirement whether meeting step 4 setting judges, judges whether to meet threshold requirement: if meet this requirement, record is formed standard, successfully exit; If do not meet this requirement, v reduces 1, repeats step B, again enters circulation and carries out calculating judgement;

Wherein, get rid of the impact of diagonal entry, the sum that v (v-1) is surplus element.

The Advantageous Effects adopting as above technical scheme to obtain is:

The present invention takes full advantage of the feature that Electronic Calibration part can store information, available standards is marked, without the need to changing hardware aspect.

The present invention is calculated by calibrating device canonical measure, utilize the correlativity to Electronic Calibration part calibration standard, calculate correlation matrix, and obtain the weak standard of correlativity according to threshold value, effectively can avoid the phenomenon of " rule violations ", the standard of mark applies in calibration process, improve speed and the precision of calibration, and productibility is strong.

Standard Selection process, after the calibration of Electronic Calibration part, only needs automatically to be calculated by program according to calibration data, without the need to artificial participation, is applicable to automated production.

Accompanying drawing explanation

Fig. 1 is single port error model.

Fig. 2 is dual-port electronic standard structural drawing.

Fig. 3 is electronic standard part impedance plot.

Fig. 4 is the process flow diagram utilizing selection standard to carry out selection standard combination.

Embodiment

4 pairs of the specific embodiment of the present invention are described further by reference to the accompanying drawings:

For the calibration criterion choosing method of vector network analyzer Electronic Calibration part, it is characterized in that, described calibration criterion choosing method adopts following steps:

Step 1, the scaled values (normally real part imaginary numbers) of Electronic Calibration part is converted into the numerical value on Smith chart, and the scaled values number of Electronic Calibration part is n;

Step 2, utilizes Solving Equations to solve correlation values r (i, j) between various criterion scaled values;

Step 3, forms matrix R by all relevance parameter obtained in step 2;

Step 4, the relevant tolerance threshold value z (0<z<1) of setting;

Step 5, utilizes selection standard to carry out selection standard combination;

Step 6, in Electronic Calibration part firmware program, the standard combination that markers step 5 is chosen;

Step 7, when utilizing Electronic Calibration part to calibrate, the standard of selected marker is carried out measuring and is carried out solving of single port error;

Step 8, utilizes single port systematic error, obtains transmission tracking, load matched error in conjunction with straight-through measurement data.

Following Solving Equations is utilized to solve correlation values between various criterion scaled values in described step 2:

$r(i,j)=\frac{\underset{t=1}{\overset{p}{\mathrm{\&Sigma;}}}({\mathrm{\&Gamma;}}_{it}-\stackrel{\&OverBar;}{{\mathrm{\&Gamma;}}_i})({\mathrm{\&Gamma;}}_{jt}-\stackrel{\&OverBar;}{{\mathrm{\&Gamma;}}_j})}{\sqrt{\underset{t=1}{\overset{p}{\mathrm{\&Sigma;}}}{({\mathrm{\&Gamma;}}_{it}-\stackrel{\&OverBar;}{{\mathrm{\&Gamma;}}_i})}^2\underset{t=1}{\overset{p}{\mathrm{\&Sigma;}}}{({\mathrm{\&Gamma;}}_{jt}-\stackrel{\&OverBar;}{{\mathrm{\&Gamma;}}_j})}^2}}$

Wherein: t is scaling point, p is scaling point sum, Γ _itbe the scaled values of i-th standard on scaling point t, be the mean value of i-th all scaled values of standard, r (i, j) represents the correlativity of i-th standard and a jth standard, and r (i, j)=r (j, i).

In described step 3, matrix R is:

$R=\left[\begin{array}{cccc}r(1,1)& r(1,2)& ...& r(1,n)\\ r(2,1)& r(2,2)& ...& ...\\ ...& ...& ...& ...\\ r(n,1)& r(n,2)& ...& r(n,n)\end{array}\right].$

Utilize selection standard to carry out selection standard combination in described step 5 and adopt following steps:

A, the criterion numeral chosen are v, make v=n;

If B v≤3 (because form least squares equation demand fulfillment equation number to be greater than unknown number, meeting the requirement that equation (2) is greater than 3 unknown numbers), then do not have satisfactory combination, exit computing;

If v > 3, in n standard, choose v standard (always have individual combination), obtain correlation matrix for each combination by step 3, and be denoted as to R _v1matrix element ask modulus value, then element is cumulative obtains in like manner matrix calculate from in find minimum value, be denoted as

C, right the threshold requirement whether meeting step 4 setting judges, judges whether to meet threshold requirement: if meet this requirement, record is formed standard, successfully exit; If do not meet this requirement, v reduces 1, repeats step B, again enters circulation and carries out calculating judgement;

Wherein, get rid of the impact of diagonal entry, the sum that v (v-1) is surplus element.

N is criterion numeral altogether, is the criterion numeral chosen for n=8, v.When calculating beginning, make v=n (=8).Enter Rule of judgment, if v≤3 (because form least squares equation demand fulfillment equation number to be greater than unknown number, meeting the requirement that equation (2) is greater than 3 unknown numbers), then there is no satisfactory combination, exit computing.

V > 3, chooses v standard and (always has in n standard individual combination), for each combination by formula $R=\left[\begin{array}{cccc}r(1,1)& r(1,2)& ...& r(1,n)\\ r(2,1)& r(2,2)& ...& ...\\ ...& ...& ...& ...\\ r(n,1)& r(n,2)& ...& r(n,n)\end{array}\right]$ Calculate correlation matrix, and be denoted as (routine as v=7, R _v1corresponding standard is 1,2,3,4,5,6,7; R _v2corresponding standard is 1,2,3,4,5,6,8; R _v3corresponding standard is 1,2,3,4,5,7,8; ).To R _v1matrix element ask modulus value, then element is cumulative obtains in like manner matrix calculate from in find minimum value, be denoted as

It is right finally to need the threshold requirement arranged before whether meeting judges.Because, the elements in a main diagonal in correlation matrix be 1 (such as certain calculate in correlation matrix numerical value be $R=\left[\begin{array}{cccc}1& 0.8& ...& 0.3\\ 0.8& 1& ...& ...\\ ...& ...& ...& ...\\ 0.3& 0.5& ...& 1\end{array}\right]$ ), so first get rid of the impact of diagonal entry, will and then divided by the total v (v-1) of surplus element.Finally judge whether to meet threshold requirement: if meet this requirement, then obtain the standard combination wanted, successfully exit.If do not meet this requirement, v reduces 1, again enters circulation and carries out calculating judgement.

Said process is the correlation analysis of whole frequency range.Found by Fig. 3 and test, occur that the probability of " rule violations " is lower in low-frequency range, and higher at the probability of high-frequency appearance.So, for the Electronic Calibration part that frequency coverage is wider, take the mode of segmentation to process.As 45M-67G Electronic Calibration part, be divided into 45M-15G, 15G-30G, 30G-45G, 45G-67G tetra-sections, carry out computing.

Certainly; more than illustrate and be only preferred embodiment of the present invention; the present invention is not limited to enumerate above-described embodiment; should be noted that; any those of ordinary skill in the art are under the guidance of this instructions; made all equivalently to substitute, obvious form of distortion, within the essential scope all dropping on this instructions, protection of the present invention ought to be subject to.

Claims (4)

1. for the calibration criterion choosing method of vector network analyzer Electronic Calibration part, it is characterized in that, described calibration criterion choosing method adopts following steps:

Step 1, by the numerical value that the scaled values of Electronic Calibration part is converted on Smith chart, the scaled values number of Electronic Calibration part is n;

Step 2, utilizes Solving Equations to solve correlation values r (i, j) between various criterion scaled values;

Step 3, forms matrix R by all relevance parameter obtained in step 2;

Step 4, the relevant tolerance threshold value z (0<z<1) of setting;

Step 5, utilizes selection standard to carry out selection standard combination;

Step 6, in Electronic Calibration part firmware program, the standard combination that markers step 5 is chosen;

Step 7, when utilizing Electronic Calibration part to calibrate, the standard of selected marker is carried out measuring and is carried out solving of single port error;

Step 8, utilizes single port systematic error, obtains transmission tracking, load matched error in conjunction with straight-through measurement data.

2. the calibration criterion choosing method for vector network analyzer Electronic Calibration part according to claim 1, is characterized in that, utilizes following Solving Equations to solve correlation values between various criterion scaled values in described step 2:

$r(i,j)=\frac{\underset{t=1}{\overset{p}{\mathrm{\&Sigma;}}}({\mathrm{\&Gamma;}}_{it}-\stackrel{\&OverBar;}{{\mathrm{\&Gamma;}}_i})({\mathrm{\&Gamma;}}_{jt}-\stackrel{\&OverBar;}{{\mathrm{\&Gamma;}}_j})}{\sqrt{\underset{t=1}{\overset{p}{\mathrm{\&Sigma;}}}{({\mathrm{\&Gamma;}}_{it}-\stackrel{\&OverBar;}{{\mathrm{\&Gamma;}}_i})}^2\underset{t=1}{\overset{p}{\mathrm{\&Sigma;}}}{({\mathrm{\&Gamma;}}_{jt}-\stackrel{\&OverBar;}{{\mathrm{\&Gamma;}}_j})}^2}}$

Wherein: t is scaling point, p is scaling point sum, Γ _itbe the scaled values of i-th standard on scaling point t, be the mean value of i-th all scaled values of standard, r (i, j) represents the correlativity of i-th standard and a jth standard, and r (i, j)=r (j, i).

3. the calibration criterion choosing method for vector network analyzer Electronic Calibration part according to claim 1, it is characterized in that, in described step 3, matrix R is:

$R=\left[\begin{array}{cccc}r(1,1)& r(1,2)& ...& r(1,n)\\ r(2,1)& r(2,2)& ...& ...\\ ...& ...& ...& ...\\ r(n,1)& r(n,2)& ...& r(n,n)\end{array}\right].$

4. the calibration criterion choosing method for vector network analyzer Electronic Calibration part according to claim 1, is characterized in that, utilizes selection standard to carry out selection standard combination and adopt following steps in described step 5:

A, the criterion numeral chosen are v, make v=n;

If B v≤3, then there is no satisfactory combination, exit computing;

If v > 3, in n standard, choose v standard (always have individual combination), obtain correlation matrix for each combination by step 3, and be denoted as to R _v1matrix element ask modulus value, then element is cumulative obtains in like manner matrix calculate from in find minimum value, be denoted as

C, right the threshold requirement whether meeting step 4 setting judges, judges whether to meet threshold requirement: if meet this requirement, record is formed standard, successfully exit; If do not meet this requirement, v reduces 1, repeats step B, again enters circulation and carries out calculating judgement;

Wherein, get rid of the impact of diagonal entry, the sum that v (v-1) is surplus element.