Efficient power supply for telemetry sensor nodes

Unidirectional telemetry systems for long range wireless data transmission are becoming more and more important for localization and sensor applications. A small size of the transmitter nodes, required for mobility, can only be reached by the use of tiny batteries. This paper explains, how an energy storage device like a capacitor can help to handle the current limitation of such batteries, e.g. coin cell batteries. Different circuits for the charge of the capacitor and for the power supply of sensor nodes are discussed. The efficiencies of the supply concepts are calculated and compared. The realizable number of transmissions for the different power concepts and a given type of battery is estimated. As a consequence of our calculations the optimal power concept could be implemented into our 1 cm³ cubic transmitter demonstrator, which is introduced in this paper.