Development of a wireless environmental sensor system and MEMS-based RF circuit components

This paper reports a miniaturized environmental sensor system integrated with RF communication module. This system has been developed for on-site monitoring of water pollution by heavy metal ions. The system is composed of an electrochemical sensor, a custom potentiostat module, and an RF module for wireless communication. Also, the authors presented monolithic MEMS VCOs integrated with high-Q MEMS inductors and MEMS transmission lines for low-power wireless transceiver applications. Phase noise of the proposed MEMS VCOs has been improved by more than 7 dBc/Hz compared with their CMOS counterparts at 1MHz offset from center frequencies of 5GHz and 13 GHz, respectively.