Weak Signal Detection Utilizing a Mechanically Switched Inductor

摘要

These days an increasing number of applications have a need for always-on sensor interfaces for processing and analysis of sensor signals. One function most of these interfaces have in common is signal rectification. Seeing how these interfaces are always on, their parts should have low power consumption. This leads us to the idea of an electromechanical rectifier for weak signal rectification that could increase the rectified voltage levels with no additional power consumption, as it would get the energy needed for its operation from the very phenomenon that is observed. Motivated by this application scenario, an electrical analysis of the weak signal detection utilizing a mechanically switched inductor was done, considering a low-impedance weak signal source. After the theoretical analysis, simulations of the proposed electromechanical topology were presented. Finally, an experimental demonstration was done utilizing an RMSHI circuit corroborating the applicability of this concept in weak signal detector for an always-on interface. The experimental results show that it is possible to detect a minimal input voltage between 40 mV and 50 mV peak-to-peak for the macroscopic RMSHI device.