Analysis of CMOS-Based mm-Wave Rectifiers: A Comprehensive Survey

Millimeter-wave (mm-wave) frequencies are attractive for energy harvesting in IoT devices because of their high energy density, which allows for more power to be captured in a smaller space. These frequencies enable the use of smaller, high-gain antennas, for compact devices, and offer wider bandwidths, thus supporting both energy-harvesting and high-data-rate communications simultaneously. The demand for IoT devices with increasingly smaller form factors has necessitated the use of mm-wave frequencies, enabling on-chip antenna integration and further reducing device size. With the expansion of the deployment of millimeter waves in 5G networks, the increasing availability of ambient millimeter wave signals presents new opportunities for IoT devices to harvest energy. This review paper explores the application of various rectifier topologies, including Dickson, cross-coupled, inductor-peaked, and Colpitts, for efficient energy conversion at mm-wave frequencies. The transistor model and the effects of parasitic capacitances at mm-wave frequencies are analyzed and presented as well. The merits and demerits of each topology concerning key rectifier parameters such as sensitivity, efficiency, and overall performance are also presented.