Silicon Carbide Functional Primitives for Wireless Sensor Nodes

While wireless sensor nodes based on conventional semiconductor technology have revolutionized our understanding of the world in which we live, they are limited to operating in benign environments. This limitation precludes their use in a wide range of industrial, automotive and geological applications, where the required operating temperatures can exceed 200\ub0C. Silicon-on-insulator technology has enabled the development of high temperature electronics, however applications requiring higher temperature operation are becoming apparent. Battery technologies capable of sustaining the required power level in these extreme environments are also a significant challenge. In this work, we present the integration of analog functional primitive circuits capable of interrogating resistive and capacitive sensors to form a wireless sensor node based on silicon carbide technology. The electrical power is provided from the output of a novel self-starting boost converter connected to a thermoelectric generator. Data can be transmitted from the node via frequency modulation of a Colpitts oscillator, for remote post processing. The signal conditioning is realised using JFET based amplifier circuits, designed using a novel JFET compact model, which enables a greater level of confidence than existing models in the literature