Patent ID: 11867736
Assignee: nan
Field: Measurement (Instruments)
Classification: CPC G  H | IPC G

Claim 6:
7. An impedance synthesis (tuning) method for the automated two-probe waveguide load pull tuner of claim 6 comprising:
a) for a frequency F, define a tuning tolerance TOL and a tuner calibration data file and retrieve s-parameters Sij(X1,X2) from the calibration data file;
b) define a tuning target reflection factor Γ=|Γ|*exp(jΦ) and a maximum number of iterations NMAX;
c) search in s-parameter Sij(X1,X2) for a calibration point Sij(X1o,X2o), for which an error function EF=|S11(X1o,X2o)−Γ|2, defined as the square of the absolute vector difference between the reflection factor S11(X1o,X2o) and the target Γ, is minimum;
d) if EF≤TOL, define X1.final=X1o, X2.final=X2o and move to step (f);
e) set N=1 and search interpolated s-parameter data S11(X1,X2) in the area (X1,X2) close to the calibrated point (X1o,X2o) for a final setting (X1.final,X2.final) as follows:
e1) from starting point (X1o,X2o), in a search loop of position X1 of the tuning probe P #1:
set N=N+1 and change X1o by a small amount δX1 to X1o+δX1, calculate the Error Function EF=|S11(X1o+δX1,X2o)−Γ|2,
make δX1 proportional to the change of EF, increase N and iterate until EF reaches a minimum, and then set X1o′=X1o+δX1;

e2) from a new point (X1o′,X2o), in a search loop of position X2 of the tuning probe P #2:
set N=N+1 and change X2o by a small amount δX2 to X2o+δX2, calculate the Error Function EF=|S11(X1o′,X2o+δX2)−Γ|2,
make δX2 proportional to the change of EF, increase N and iterate until EF reaches a minimum, and then set X2o′=X2o+δX2;

e3) set X1o=X1o′, X2o=X2o′ and repeat steps e1) and e2) until there is no further reduction of EF occurs or if N>NMAX;
e4) define X1.final=X1o′, X2.final=X2o′; 

f) move the tuning probe P #1 to X1.final and tuning probe P #2 to X2.final.