Multi-section probes for broadband impedance tuners
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Solution Overview
Problem
Mechanical impedance tuners face a narrow bandwidth due to the use of single-section probes, which limits their ability to simulate a wide range of impedance values effectively in microwave and RF measurements.
Innovation Solution
Implementing multi-section probes with adjacent sections positioned at stepped heights or varying trough profiles, or using tapered quarter wave transformers to achieve a stepped or continuous impedance transformation, allowing for broader bandwidth by adjusting the number of sections and their characteristics to match desired impedance values.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If single-section probes are used in mechanical impedance tuners, then the device structure is simple, but the bandwidth is narrow
Solution Approach 1:
The probe is divided into multiple sections, each with different heights above the center conductor. This segmentation allows each section to contribute differently to the impedance transformation, enabling broader bandwidth operation while maintaining a relatively simple overall structure. The multi-section design transforms the single-function probe into a multi-functional component that can handle multiple impedance values across a wider frequency range.
2Reliability
If probes are moved closer to the center conductor to increase impedance mismatch, then high reflections are generated for impedance transformation, but the bandwidth becomes narrower
Solution Approach 1:
Different sections of the probe have different local qualities, specifically different heights above the center conductor. This creates a gradient of impedance transformations along the probe length, where each section contributes to a specific portion of the bandwidth. The local quality variation allows the probe to maintain effective impedance transformation across a broader frequency range rather than concentrating the transformation effect at a single location.
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 approach significantly widens the bandwidth of impedance tuners, enabling them to simulate a wide range of impedance values efficiently, as demonstrated by simulations and adjustments using 3D electromagnetic field simulators.
Implementation Method 1
the probes can generate high reflections and act to transform the characteristic impedance of the slab line to other impedance values
Implementation Method 2
using tapered quarter wave transformers to achieve a stepped or continuous impedance transformation
Implementation Method 3
The probes can generate high reflections and act to transform the characteristic impedance of the slab line to other impedance values
Data Source
AI summary
A multi-section probe and a tapered probe for impedance tuners to broaden the band width of the probes and hence the band width of the tuners. The multi-section probe and the tapered probe are configured to transform the characteristic impedance of the tuner transmission line step-by-step or continuously to a target impedance value.