The Advancement of Radio Frequency Energy Harvesters (RFEHs) as a Revolutionary Approach for Solving Energy Crisis in Wireless Communication Devices: A Review

In this paper, the evolution and milestones of RFEH and related breakthroughs over the years are reviewed and presented. The review begins with an overview of the surging energy crisis due to the increasing demand for wireless communication devices. Furthermore, the RFEH mechanism that discusses the frequency bands utilized, the near field, and the far-field propagation are also presented. Various rectification techniques in CMOS RFEH, from the fundamental rectification method to cross-coupled-differential-drive (CCDD), are also examined and discussed. The performance is gauged through harvested output DC voltage and the power conversion efficiency (PCE) as well as the RF input power sensitivity. An assessment on the non-CMOS RFEH that includes the Schottky diode and Rectenna is also concisely described to analyze their contribution to RFEH’s performances enhancement. Finally, a particular highlight of the 5G RFEH in mmWave is provided in presenting this work as an ongoing future solution to reduce the electronic circuit’s battery dependency. The pros and cons of all the presented RFEHs are summarized and discussed as well. Continuous research and development activities are extensively being executed in developing a system that could ultimately solve the world’s energy crisis, and RFEH seems to be a revolutionary approach.