Slot antenna packaging for infrastructure monitoring based on wake-up transceiver strategy

The use of the package as a radiating element is the optimal solution in term of robustness for wireless sensor network (WSN) applications such as infrastructure monitoring. A robust, 83 % efficient and 6.5 dBi gain slot antenna packaging (simulation values in air) for wireless sensor nodes working at 868 MHz is presented in this paper. A low power wake-up radio transceiver strategy allowing a current consumption of 3.8 μA is associated to the radiating package. The theoretical battery life time for a 3 V input voltage and a 220 mA/h battery capacity is more than 6 years using the proposed system. Therefore the combination between the antenna packaging and wake-up approach increases the wireless system life time. Finite Element Method (FEM) simulation and experimental results are presented to show the effects of different concrete supports on the antenna performances. Moreover, indoor and outdoor wake-up rate measurements show the coverage efficiency of the complete device. Using a transmission power of +10 dBm and a wake-up sensitivity of -51.8 dBm, a distance of 55 meters is reached in comparison to more than 250 meters for data transmission.