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Updated: Sep 9, 2025
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Calibration of Vector Network Analyzer for Measurements in Radio Frequency Propagation Channels
Published on: June 2, 2020
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The Effect of Scratch-Induced Microscale Surface Roughness on Signal Transmission in Radio Frequency Coaxial
Yuqi Zhou1, Tianmeng Zhang1, Gang Xie2
1Beijing Key Laboratory of Work Safety Intelligent Monitoring, Beijing University of Posts and Telecommunications (BUPT), Beijing 100876, China.
Micromachines
|August 28, 2025
Summary
Microscale surface roughness significantly impacts RF coaxial connector performance. Moderate roughness improves signal integrity, while excessive roughness degrades it, crucial for high-frequency microsystems.
Area of Science:
- Electrical Engineering
- Materials Science
- Physics
Background:
- Reliable signal transmission in high-frequency microsystems depends on electrical connectors.
- Traditional analyses often overlook the impact of surface imperfections on connector performance.
Purpose of the Study:
- To investigate the quantitative relationship between microscale scratch-induced surface roughness and AC contact impedance in RF coaxial connectors.
- To understand how surface morphology affects signal degradation in high-frequency applications.
Main Methods:
- Controlled introduction of micro-defects at the contact interface.
- Development and validation of an equivalent circuit model using S-parameter measurements from Vector Network Analyzer (VNA) testing.
- Analysis of scratch-induced roughness effects ranging from 0.4 μm to 4.8 μm.
Main Results:
- Low roughness (0.4 μm) resulted in degraded signal integrity due to poor micro-contact formation.
- Moderate roughness (0.8-4.8 μm) initially improved transmission performance, but performance decreased with increasing roughness.
- Signal degradation was amplified in multi-connector setups due to cumulative impedance mismatches.
Conclusions:
- Microscale surface features critically influence the frequency-domain transmission characteristics of RF connectors.
- Findings offer practical guidance for surface engineering and contact design in miniaturized, high-reliability RF interconnects for advanced communication systems.
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