Erhardt, StefanStefanErhardtWeigel, RobertRobertWeigelKölpin, AlexanderAlexanderKölpin2020-06-302020-06-302019-05-09IEEE Topical Conference on Wireless Sensors and Sensor Networks, WiSNet: 8711804 (2019-05-09)http://hdl.handle.net/11420/6503In this publication a logger is introduced that is small and lightweight enough to be carried by bats. It tracks the GSM downlink spectrum, enabling coarse localization. The logger contains a Sub-GHz transceiver, a microcontroller and a DC/DC converter assembled on a flexible printed circuit board (PCB) that is directly mounted on a lithium coin cell battery. The total weight is approximately 2.1 g and the size is comparable to two stacked 1 Euro Cent coins after coating the logger with epoxy resin. A flexible nickel titanium wire antenna is used for receiving GSM signals and for transmitting in the European 868 MHz short-range devices (SRD) band. In a short-term field test the functionality was proven.enConference Paper10.1109/WISNET.2019.8711804Other