Pattern-Reconfigurable Antennas and Smart Wake-Up Circuits to Decrease Power Consumption in WSN Nodes

In this letter, a recently proposed power efficient wireless sensor network node mounting a pattern-reconfigurable antenna has been enhanced through the design and use of a wake-up circuit based on a RF power meter. In such a way, the RF frontend is smartly activated only when a potential communication is sensed, thus even more reducing the node power consumption. Tests demonstrate that the wake-up circuit allows a reasonable working distance of 55 m. Moreover, a reduction of the power consumption of ∼ 21 % with respect to our previous solution, and of ∼ 40 % with respect a standard node, is obtained.