Anti-skewing impedance tuner
View Patent ↗A slide screw tuner uses a tuning probe that penetrates into the slot of the slabline inclined towards the test port, in order to compensate for the capacitive skewing of the angle of the reflection factor Γ. This anti-skewing effect is done by splitting the mobile combo carriage into a fixed and a rotating section, held together by a center pin that allows an adjustable inclination. The linearized trajectory of Γ improves the accuracy of interpolation between calibration points.
1. A slide screw impedance tuner comprising,
a low loss slotted transmission airline (slabline) having a test port, an idle port and a center conductor between the test and idle ports,
and at least one remotely controlled mobile combo carriage sliding horizontally along the slabline, controlled by an Acme lead screw, and an electronic motor control board;
said at least one remotely controlled mobile combo carriage comprising
one fixed section and one section rotating against the fixed section on a plan parallel to the center conductor of the slabline,
wherein
a horizontal position of the one fixed section is controlled by the Acme lead screw,
and wherein
the one rotating section holds a vertical axis and is linked with the one fixed section using a center pin;
and wherein
the vertical axis holds a metallic tuning probe having a stem held by the vertical axis and a bottom section insertable into a slot of the slabline.
2. The slide screw impedance tuner of claim 1
wherein
a rotation angle between the one fixed section and the one rotating section is adjustable.
3. The slide screw impedance tuner of claim 1
wherein
the bottom section of the tuning probe has a concave periphery with semi-circular profile,
and wherein
a channel of the concave bottom section is parallel to the center conductor.