Harmonic Load Pull Tuner With Horizontal Probe Movement

Solution Overview

Problem

Existing load pull impedance tuners require high precision and cumbersome vertical probe movement mechanisms, leading to slow tuning procedures due to the need for precise positioning close to the center conductor, which increases mechanical complexity and risk of spurious oscillations in microwave component testing.

Innovation Solution

A slide screw load pull harmonic tuner with horizontal-only high-speed tuning probe movement and a low-profile design using a bent center conductor, eliminating the need for adjustable vertical axes and allowing for a neutral 50 Ohm tuning state, enabling fast calibration and reduced mechanical error sensitivity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If vertical probe movement mechanisms are used to achieve precise positioning close to the center conductor, then measurement precision is improved, but device complexity increases and tuning speed decreases

Engineering Contradiction:

Improveimpedance tuning precisionVSAvoidmechanical complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent inverts the conventional vertical probe movement approach by implementing horizontal probe movement along the slabline. Instead of moving probes vertically close to the center conductor to achieve impedance tuning, the probes move horizontally along the length of the slabline, fundamentally changing the direction of movement and eliminating the need for complex vertical positioning mechanisms.

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The patent transitions from one-dimensional vertical movement to one-dimensional horizontal movement along the slabline axis. This dimensional change allows the probes to achieve impedance tuning by varying their horizontal position rather than vertical proximity to the center conductor, thereby simplifying the mechanical structure while maintaining tuning precision.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Measurement precision

If vertical probe movement mechanisms are used to achieve precise positioning, then measurement precision is improved, but tuning speed decreases

Engineering Contradiction:

Improveimpedance tuning precisionVSAvoidtuning speed

Core Design Contradiction:

Measurement precisionVSProductivity

Solution Approach 1:

The patent inverts the conventional vertical probe movement approach by implementing horizontal probe movement along the slabline. Instead of moving probes vertically close to the center conductor to achieve impedance tuning, the probes move horizontally along the length of the slabline, fundamentally changing the direction of movement and eliminating the need for complex vertical positioning mechanisms.

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The patent extracts and removes the complex vertical movement mechanism from the system entirely. By eliminating the vertical axis and relying solely on horizontal probe movement, the design simplifies the mechanical structure and removes the bottleneck that limited tuning speed in conventional load pull tuners.

Inventive Principle:

Principle #2Taking out (Extraction)

3Measurement precision

If probes are positioned very close to the center conductor to achieve high reflection factors, then measurement precision is improved, but the risk of spurious oscillations increases

Engineering Contradiction:

Improvereflection factor controlVSAvoidspurious oscillations

Core Design Contradiction:

Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent inverts the conventional vertical probe movement approach by implementing horizontal probe movement along the slabline. Instead of moving probes vertically close to the center conductor to achieve impedance tuning, the probes move horizontally along the length of the slabline, fundamentally changing the direction of movement and eliminating the need for complex vertical positioning mechanisms.

Inventive Principle:

Principle #13The other way round (Inversion)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This configuration enables faster and more accurate impedance tuning with reduced mechanical complexity, minimizing the risk of spurious oscillations and allowing for efficient on-wafer integration by maintaining a low profile, thus enhancing the speed and precision of load pull measurements.

Implementation Method 1

This movement of the tuning probes creates capacitive coupling and a controllable variable reactance, allowing the synthesis of various impedances

Methodology Applied

Scientific EffectCapacitive coupling: Capacitance

Implementation Method 2

When parallelepiped metallic tuning probes (slugs) with a concave bottom, attached to a vertical control mechanism (vertical axis) approach the center conductor, they capture and deform the electric field, which is stronger in the area between the center conductor and the ground planes of the slabline

Methodology Applied

Scientific EffectElectric field deformation: Electric Field

Data Source

PatentUS12259409B1Harmonic load pull tuner

Publication Date: 2025.03.25 FOCUS MICROWAVES

AI summary

A low profile four probe harmonic load-pull slide screw impedance tuner uses four tuning probes sharing the same slabline; they are inserted in pairs diametrically 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 vertical axes controlling the penetration of the tuning probes and its low profile is optimal for on-wafer operations with direct wafer probe contact. The carriages holding the tuning probes are moved at high speed along the slabline using linear electric actuators. The “S” shaped center conductor allows for a neutral, probe withdrawn, 50 Ohm state. A fast de-embedding calibration method allows speeding up the measurement procedure.