Smart Solutions in Smart Spaces: Getting the Most from Far-Field Wireless Power Transfer

In this article, the authors have considered some of the most recent RF/microwave circuit and signaling solutions to assist wireless powering of maintenance-free devices and to take a step forward in the reliable implementation of cooperative smart spaces. This is currently among the most important requirements for the increasingly widespread world of pervasive monitoring, including ambient assisting living, structural monitoring, e-health, agriculture, and risk-preponderant working environments. In such scenarios, lowduty-cycle, low-power (tens of nW) wireless sensors nodes are adopted, possibly realized in eco-friendly material and without batteries.