An autarkic sensor system has been developed, integrating both a wireless power transfer to the sensor and a wireless data transfer to a reader station. The system was designed for the measurement of temperature or other inputs and for data transfer to a base station every second. It is composed of a finely structured energy accumulation coil, suited for 13.56MHz. The so accumulated energy is used for running the system including sensor monitoring, A/D conversion and active data transfer with a loop antenna at a range of 868.3 MHz. The sensor part of the system includes microcontroller, quartz and capacitor, and is designed for an operation range of up to several meters. The sensor system is placed on a printed circuit on foil and moulded in temperature resistant polymer of a size of 20 times 22 times 3 mm, at a total weight less than 2g, caused mainly by the weighty moulding polymer. Since no battery or wet chemistry processes are used, any maintenance could be neglected