Active rectifiers combine a high-gain amplifier (used as a comparator) and actively controlled switches to provide reduced turn-on voltage compared to p-n and Schottky diodes. Most reports of active rectifiers use silicon MOS transistor technology, however for some applications it is useful to combine active rectifiers with micro-electromechanical systems (MEMS) or to provide active rectifiers distributed over a large area. For such applications active rectifiers using thin film transistors (TFTs) are of interest. In this paper, we demonstrate a low-power full-wave active rectifier fabricated using double-gate ZnO TFTs. The double-gate TFT structure allows tuning of the device turn-on voltage and threshold voltage by biasing the top gate . This simplifies fabrication of enhancement/depletion mode circuits and allows high gain inverter stages that operate at low power.