Edoardo Boretti | Searcharxiv

arXiv2026

Design and Repeatability Assessment of an RF MEMS Switching Platform for Automated Microwave SOL Calibration

This work presents a compact RF MEMS switching platform for automated one-port SOL calibration of microwave lines. The system is based on a Menlo Micro MM5230 SP4T RF MEMS switch integrated on a grounded coplanar waveguide board and driven by a dedicated MM101-based high-voltage control circuit. The board design is presented, and the repeatability of the calibrated reflection coefficient is assessed through the covariance matrix evaluated from 100 repeated SOL calibration measurements. The platform is tested from 100~kHz to 20~GHz with a Rohde \& Schwarz ZNB43 VNA and the performance compared with an electromechanical microwave switch. The RF MEMS fixture shows lower dispersion of the calibrated reflection coefficient and improved temporal stability, demonstrating its suitability for repeatable automated microwave calibration in measurement environments where compactness, low mass, thermal constraints, and reduced power dissipation are key requirements.

physics.ins-det↗

arXiv2025

Scalable Relay Switching Platform for Automated Multi-Point Resistance Measurements

In both research and industrial settings, it is often necessary to expand the input/output channels of measurement instruments using relay-based multiplexer boards. In research activities in particular, the need for a highly flexible and easily configurable solution frequently leads to the development of customized systems. To address this challenge, we developed a system optimized for automated direct current (DC) measurements. The result is based on a 4x4 switching platform that simplifies measurement procedures that require instrument routing. The platform is based on a custom-designed circuit board controlled by a microcontroller. We selected bistable relays to guarantee contact stability after switching. We finally developed a system architecture that allows for straightforward expansion and scalability by connecting multiple platforms. We share both the hardware design source files and the firmware source code on GitHub with the open-source community. This work presents the design and development of the proposed system, followed by the performance evaluation. Finally, we present a test of our designed system applied to a specific case study: the DC analysis of complex resistive networks through multi-point resistance measurements using only a single voltmeter and current source.

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