Granted Patent B1

US 12,347,916 · App. 17/965,900 · Granted Jul 1, 2025

Inventor: Christos Tsironis (Kirkland, CA)

H01P5/04G01R31/2822H01P1/222H03H7/40

Abstract

Claims (42)

1. A calibration method for a waveguide slide screw tuner having a test port and an idle port, and two tuning probes, a first tuning probe and a second tuning probe, inserted diametrically and laterally offset to each other into slots on opposite broad walls of the waveguide and movable at constant penetration along the waveguide, comprising the following steps:

a) connect the tuner to a VNA pre-calibrated at a frequency F;

b) move the tuning probes to initial positions, the first tuning probe to X 1 . 0 and the second tuning probe to X 2 . 0 ;

c) measure s-parameters of the tuner and save in an init matrix [S 0 ];

d) in a first move-measurement loop

d1) move the first tuning probe from X 1 =X 1 . 0 to at least X 1 =X 1 . 0 +λ/2 in N steps of ΔX=λ/(2N),

d2) measure s-parameters and save in a file S 1 including Sij(X 1 ,X 2 . 0 );

e) return the first tuning probe to position X 1 =X 1 . 0 ;

f) in a second move-measurement loop

f1) move the second tuning probe from X 2 =X 2 . 0 to at least X 2 =X 2 . 0 +λ/2 in N steps of ΔX=λ/(2N),

f2) measure s-parameters and save in a file S 2 including Sij(X 1 . 0 ,X 2 );

g) in a third move-measurement loop

move the first tuning probe from X 1 =X 1 . 0 to at least X 1 =X 1 . 0 +λ2 in steps of ΔX and, for each movement of the first tuning probe, move the second moving probe from X 2 =X 1 −M*ΔX to X 2 =X 1 +M*ΔX in steps of ΔX, with M=0, 1, 2, 3 . . . and measure s-parameters and save in files SK including Sij(X 1 ,X 2 ), for 3≤K≤3+2M;

h) in a numerical cascading loop for all permutations {X 1 ,X 2 }

if the first tuning probe is closer to the test port (X 1 ≤X 2 ) de-embed s-parameters of the second tuning probe: cascade s-parameters [S 1 ]*[S 0 ] −1 *[S 2 ] and save in file C 1 ;

if the second tuning probe is closer to the test port (X 1 >X 2 ) de-embed the first tuning probe: cascade s-parameters [S 2 ]*[S 0 ] −1 *[S 1 ] and save in file C 2 ;

i) concatenate s-parameters of files C 1 with C 2 , replace s-parameters with data from files SK and save s-parameters Sij(X 1 ,X 2 ) in a tuner calibration file C(F).

2. The calibration method as in claim 1

wherein

the slots of the waveguide slide screw tuner to which the calibration method applies are at least one half of a wavelength (λ/2) long at a minimum operation frequency (Fmin).

3. The calibration method as in claim 1

wherein

the tuning probes of the waveguide slide screw tuner to which the calibration method applies are controlled by remotely controlled stepper motors and appropriate gear.

4. The calibration method as in claim 1

wherein

the tuning probes of the waveguide slide screw tuner to which the calibration method applies are metallic or at least partly metallized rods.

5. The calibration method as in claim 1

wherein

the tuning probes of the waveguide slide screw tuner to which the calibration method applies are metallic or at least partly metallized slabs.

6. The calibration method as in claim 1

wherein

the tuning probes of the waveguide slide screw tuner to which the calibration method applies are inserted contactless into the slots.

7. The calibration method as in claim 1

wherein the initialization coordinates of the tuning probes of the waveguide slide screw tuner to which the calibration method applies are X 1 . 0 =X 2 . 0 =0.

8. An impedance synthesis (tuning) method for the two-probe waveguide slide screw tuner calibrated using the calibration method as in claim 1 comprising the following steps:

a) enter a frequency F;

b) enter a target reflection factor Gamma;

c) load s-parameters Sij(X 1 ,X 2 ) from calibration file C(F) in memory;

d) in a search loop for all permutations {X 1 ,X 2 }

d1) compare S 11 (X 1 ,X 2 ) with Gamma;

d2) if |S 11 (X 1 ,X 2 )−Gamma| is minimum, save X 1 .T=X 1 , X 2 .T=X 2 ;

e) move the first tuning probe to X 1 .T and the second tuning probe to X 2 .T.

Assignments (2)

References Cited (17)