Technologies of antenna and phased array for wireless power transfer via radio waves

The idea of transferring power over long distances via radio waves has emerged shortly after the development of high-power microwave amplifiers. The potential applications and impact of wireless power transmission (WPT) has motivated an always increasing interest from the academic and industrial communities in the research and development of effective WPT transmitting and receiving devices. Within such a framework, this chapter is aimed at introducing and formulating the problem of designing WPT antennas and arrays for power transmission via radio waves, and at illustrating the theoretical motivations, fundamentals, and technological guidelines behind state-of-the-art strategies for the synthesis of such systems. A discussion on the current trends and envisaged development within this research area will be also provided.