Development of procedures and evaluation strategies for novel field-effect transistor sensors

In order to evaluate new types of sensors based on the eld-e ect transistor technology, a cost-e ective measurement and control system is developed. Because some new types of transistor-based sensors are particularly prone to drift and noise, a measurement system is built around evaluating the e ect of a biasing technique known as switched biasing, which has been shown to reduce drift under certain con gurations. The result is an implementation of software and hardware that is both able to control a transistor with switched biasing, explore drift-reducing switched biasing con gurations, and accurately measure its performance with relatively high precision. PreFiltering of the measured data coupled with a fast actuation of an analog-to-digital converter is realized and implemented on a FPGA in the form of a rate-adjustable CIC decimation lter, which increases the signal-to-noise ratio and reduces the required data-transfer rate. The measurement system is controlled internally by a microcontroller and is interfaced through a USB interfaces to a higher-level system, such as a computer running MATLAB, and allows for multiple measurement systems to be operated in parallel. Systematic errors related to limitations of measurement hardware such as o set, temperature and drift are evaluated and compensated for through calibration.