Design of rectenna series‐association circuits for radio frequency energy harvesting in CMOS FD‐SOI 28 nm.

Series‐connected rectenna associations are proposed to improve the harvesting performance of conventional rectenna circuits by recovering power from different directions. With an available input power of −20 dBm, post‐layout simulations evaluated the total output power of four series‐connected rectennas designed in Complementary Metal Oxide Semiconductor Fully Depleted Silicon On Insulator (CMOS FD‐SOI) 28 nm technology, to 14 µW at maximum power point (MPP), while the post‐layout simulation of a single rectenna yields 5 µW at the same input power level. However, the rectenna association performance may be significantly degraded when dealing with different input power levels among rectennas. Therefore, a passive bypass circuit has been added at the output of the series association to short‐circuit the weakest rectenna. The proposed design is cost‐effective since there is a negligible silicon penalty and no additional power losses. In the designed four series‐connected rectenna association, the total output power is 7 µW at MPP with the bypass circuit when the strongest and the weakest rectennas receive −20 and −35 dBm, respectively. Also, thanks to the bypass circuit, the efficiency of the rectenna association and the ratio of maximum achieved power are improved by, respectively, 10 and 20%. [ABSTRACT FROM AUTHOR]