Low Profile Load Pull Tuner Horizontal Probe Movement

Solution Overview

Problem

Existing RF load and source pull testing methods for medium and high power RF transistors and amplifiers using two-probe impedance tuners require high precision and resolution, leading to cumbersome vertical probe movement mechanisms that slow down the tuning process due to the need for complex vertical axis adjustments and lengthy calibration procedures.

Innovation Solution

A slide screw load pull tuner system with horizontal-only high-speed tuning probe movement and a fast custom de-embedding calibration method, utilizing a low loss slabline with spring-loaded swiveling joints and stepper actuators to eliminate the need for elaborate vertical axis control, allowing for a low profile design and reduced tuning error sensitivity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If vertical probe movement mechanisms are used to achieve high precision and resolution, then measurement precision is improved, but device complexity increases and tuning speed decreases

Engineering Contradiction:

Improvetuning precisionVSAvoidmechanism complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent inverts the conventional vertical probe movement approach by implementing horizontal probe movement instead. The tuning probes move horizontally along the transmission line rather than vertically toward the center conductor, which simplifies the mechanical mechanism while maintaining tuning precision through the horizontal displacement of the probes along the line.

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The patent replaces complex vertical mechanical adjustment mechanisms with a simpler horizontal movement system. By using horizontal-only probe movement controlled by linear actuators, the system eliminates the need for elaborate vertical axis control mechanisms while achieving the required tuning precision through alternative mechanical means.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Measurement precision

If vertical probe movement mechanisms are used to achieve high precision and resolution, then measurement precision is improved, but tuning speed decreases

Engineering Contradiction:

Improvetuning precisionVSAvoidtuning speed

Core Design Contradiction:

Measurement precisionVSSpeed

Solution Approach 1:

The patent inverts the conventional vertical probe movement approach by implementing horizontal probe movement instead. The tuning probes move horizontally along the transmission line rather than vertically toward the center conductor, which simplifies the mechanical mechanism while maintaining tuning precision through the horizontal displacement of the probes along the line.

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The patent replaces complex vertical mechanical adjustment mechanisms with a simpler horizontal movement system. By using horizontal-only probe movement controlled by linear actuators, the system eliminates the need for elaborate vertical axis control mechanisms while achieving the required tuning precision through alternative mechanical means.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Measurement precision

If full calibration procedures are performed, then measurement precision is improved, but loss of time increases

Engineering Contradiction:

Improvecalibration accuracyVSAvoidcalibration time

Core Design Contradiction:

Measurement precisionVSLoss of time

Solution Approach 1:

The patent implements a fast de-embedding calibration method that performs preliminary calibration actions before actual tuning operations. By pre-characterizing the transmission line and probe positions, the system reduces the calibration required during operation from 10,000 points to just 200 points, significantly reducing calibration time while maintaining accuracy.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent uses a partial calibration approach that measures only the essential calibration points (200 points) rather than performing a complete calibration of all possible probe positions (10,000 points). This partial action is sufficient for achieving the required measurement precision while dramatically reducing the time and computational resources needed.

Inventive Principle:

Principle #16Partial or excessive action

Data Source

PatentUS11428771B1Low profile high speed load pull tuner system

Publication Date: 2022.08.30 FOCUS MICROWAVES

AI summary

A load-pull test system uses controller, interface, calibration method and at least one low profile, two-probe, slide screw impedance tuner; the tuner probes share the same slabline; they are inserted anti-diametrical at fixed depth (distance from the center conductor) from both sides into the channel and move only horizontally along the slabline. The tuner does not have adjustable high precision vertical axes controlling the penetration of the probes and its low profile is optimized for on-wafer operations. The carriages holding the probes are moved at high speed along the slabline using linear electric actuators. An efficient de-embedding calibration method serves speeding up additionally the measurement procedure.