High efficiency RF energy harvesting with threshold-votlage-adjusted gate control diode

Gate controlled diodes (GCD) and rectifiers using the GCD with the different threshold voltage (Vt) of the MOS by the ion-implantation were fabricated with 0.18 um CMOS technology. The DC characterization of the GCD revealed that the turn on voltage of the GCD is reduced and becomes lower than the Schottky Barrier Diode (SBD) when the Vt of the MOS is reduced and there exist the bulk leakage pass of the MOS on the reverse leakage current of the 0.18 um GCD. It was also clarified that the parasitic capacitance of the GCD will be lower than the SBD. From simulations and measurements of the rectifier, it was found out for the first time that the rectification efficiency of the rectifier using the GCD has a peak value when changing the Vt of MOS in the GCD, and the rectification efficiency of the rectifier using the GCD with the near zero Vt of the MOS overcomes the rectifier' using the specially designed SBD for the small signal applications, on the ultralow power input of the RF energy harvesting.