Design of high speed comparator for active rectifier

We present an active full-wave rectifier for wireless energy harvesting applications. In this technique we are going to use high speed comparators to drive the MOSFETs as Active Diode. This technique is superior to passive on-chip or off-chip rectifiers using PN junction diodes and diodes with parallel transistor or Schottky diode for low power applications. Passive rectifiers induce large forward voltage drops and power dissipation. We designed these comparators in standard CMOS technology that provides very low dropout voltage, with minimum size. High power conversion efficiency (PCE) in high frequency range is achieved by this technique. The built-in offset-control functions in the comparators compensate for both turnon and turn-off delays in the main rectifying switches, thus minimizing turn on and turn off delay and correspondingly increasing forward current and minimizing the back current. This design in implemented and simulated in tanner for 250nm technology. For an AC input of 1 volts peak with Offset of 1v provides an output of 1.7 volts when simulated in Tanner.