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Updated: Jun 23, 2026
15:25
Design and Characterization Methodology for Efficient Wide Range Tunable MEMS Filters
Published on: February 4, 2018
Impedance matching with an adjustable segmented transmission line.
1Center for Interdisciplinary Magnetic Resonance, National High Magnetic Field Laboratory, 1800 E. Paul Dirac Dr, Tallahassee, FL 32310, USA. qian@magnet.fsu.edu
Summary
This study introduces a novel segmented transmission line for radio frequency (RF) probe impedance matching in Nuclear Magnetic Resonance (NMR) spectroscopy. This method replaces traditional components, simplifying NMR probe design and tuning.
Area of Science:
- Physics
- Electrical Engineering
- Spectroscopy
Background:
- Impedance matching is crucial for Radio Frequency (RF) probes in Nuclear Magnetic Resonance (NMR) spectroscopy.
- Traditional methods like lumped elements and branched transmission lines are commonly employed.
Purpose of the Study:
- To propose and demonstrate a novel impedance matching technique using segmented transmission lines for NMR probes.
- To eliminate the need for variable capacitors and inductors in NMR probe tuning.
Main Methods:
- Utilizing a segmented transmission line structure, adapted from wireless communications.
- Implementing two quarter-wavelength dielectric slugs within a coaxial transmission line for variable tuning.
- Integrating the variable segmented transmission line into a home-built Variable Angle Spinning probe.
Main Results:
- Successfully demonstrated variable tuning and matching by adjusting slug positions.
- Eliminated the requirement for discrete variable capacitors and inductors.
- Showcased the applicability in a functional Variable Angle Spinning probe.
Conclusions:
- Segmented transmission lines offer a viable and simplified alternative for impedance matching in NMR probes.
- This approach has potential for broad application in advanced NMR probe design.
- Further exploration of segmented transmission line networks in NMR is warranted.
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