A multidirectional capacitive proximity sensor array

Abstract

This paper presents a multi-directional capacitive proximity sensor array based on band-stop filter. The band-stop filter is composed of four decoupled LC resonant circuits, so each stop band is determined by one capacitive sensor and its corresponding lumped inductor, respectively. Therefore, the change in capacitance can be obtained by measuring the change of the notches of the band-stop response. The filter is fabricated into a cubic shape for sensing different directions. Experiment results show that the fabricated sensor can detect objects coming from all four directions simultaneously by measuring the transmission at frequencies near four notches. (2014) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only. SPIE Proceedings Vol 9116This work may not be copied or reproduced in whole or in part for any commercial purpose. Permission to copy in whole or in part without payment of fee is granted for nonprofit educational and research purposes provided that all such whole or partial copies include the following: a notice that such copying is by permission of Mitsubishi Electric Research Laboratories, Inc.; an acknowledgment of the authors and individual contributions to the work; and all applicable portions of the copyright notice. Copying, reproduction, or republishing for any other purpose shall require a license with payment of fee to Mitsubishi Electric Research Laboratories, Inc. All rights reserved. ABSTRACT This paper presents a multi-directional capacitive proximity sensor array based on band-stop filter. The bandstop filter is composed of four decoupled LC resonant circuits, so each stop band is determined by one capacitive sensor and its corresponding lumped inductor, respectively. Therefore, the change in capacitance can be obtained by measuring the change of the notches of the band-stop response. The filter is fabricated into a cubic shape for sensing different directions. Experiment results show that the fabricated sensor can detect objects coming from all four directions simultaneously by measuring the transmission at frequencies near four notches.

Multi-Channel Capacitive Sensor Arrays

“…In most cases, the frequency of the electric signal is fixed, and time-division multiplexing is utilized for the readout [ 1 , 2 , 3 ]. Frequency multiplexing offers a way to increase the readout efficiency [ 6 , 7 , 8 ]. It has been shown previously that a target can be detected from the reflected signal of a transmission line with multiple capacitive elements [ 6 , 7 ].…”