Low profile millimeterwave load pull tuner
View Patent ↗A low-profile impedance tuner uses a cam-driven piston-like vertical movement of a metallic tuning probe inside a low loss slabline, controlled by an eccentrically centered disc (cam), which is attached to the axis of a stepper motor and rotates parallel to the slabline walls. The structure combines the benefits of low profile rotating tuning probe control with the benign reflection factor phase trajectory of block tuning probes; this is critical for accurate interpolation and impedance synthesis (tuning) strategies using a limited number of calibration points, especially at high microwave and millimeter-wave frequencies.
1. A method for precisely controlling a vertical penetration of a tuning probe into a slabline of a slide screw impedance tuner,
wherein the slide screw tuner comprises:
the slabline with a center conductor,
a mobile carriage, sliding along the slabline, being controlled by a first stepper motor and carrying a second stepper motor, both stepper motors being remotely controlled,
and wherein
an axis of the second stepper motor is perpendicular to the slabline, and controls an eccentrically rotating disc, whose rotation plan is parallel to the slabline, and which said disc pushes a support block towards the center conductor, which said support block is linked with the mobile carriage and is spring-loaded away from the center conductor,
and wherein
a metallic tuning probe is attached to the support block and is insertable, piston-like into the slabline, perpendicularly to the center conductor.
2. The method for precisely controlling the vertical penetration of a tuning probe into a slabline of a slide screw impedance tuner of claim 1 ,
wherein
the support block is attached to a horizontal plate, which is linked perpendicularly to a vertical plate using a hinge and held by springs anchored on the plates,
and wherein
the vertical plate is attached to the mobile carriage and the horizontal plate is pre-loaded by the springs away from the center conductor.
3. The method for precisely controlling the vertical penetration of a tuning probe into a slabline of a slide screw impedance tuner of claim 1 ,
wherein
the support block is attached to a horizontal wall of a single, wide, pre-loaded away from the center conductor steel angle, of which a vertical wall is attached to the mobile carriage.
4. The method for precisely controlling the vertical penetration of a tuning probe into a slabline of a slide screw impedance tuner of claim 1
wherein
the support block is linked with the mobile carriage using two steel angles of which a vertical wall is attached to the mobile carriage and a horizontal wall is attached to the support block, said angles being pre-loaded away from the center conductor.
5. The method for precisely controlling the vertical penetration of a tuning probe into a slabline of a slide screw impedance tuner of claim 1
wherein
the support block is formed by a steel blade parallel to the slabline, anchored on the mobile carriage, pre-loaded away from the center conductor and pushed from the top towards the center conductor by the eccentrically rotating disc, and carrying on its bottom the tuning probe.
6. The method for precisely controlling the vertical penetration of a tuning probe into a slabline of a slide screw impedance tuner of claim 1
wherein
the eccentrically rotating disc pushes the support block using a rolling contact via a ball bearing.