Voltage Generator for UHF RFID Passive Tags using Schottky diodes based on a 0.5 μm CMOS Technology

Voltage generators based on Schottky diodes have been the preferred design option to build passive tags for RFID applications. The main design constrains are commonly supply DC voltage, load current, carrier frequency, and antenna radiation resistance. In spite of this scenario the work described in this paper has applied the design methodology presented to determine basic design parameters: Schottky diode´s size, stage´s number of the circuit and also the necessary available power to cope with design´s specifications. Since Schottky diodes is not an available device of our 0.5 mum CMOS facilities, we have designed them by applying technological design rules of that technology. To do that, the I-V and C-V characteristics were simulated firstly on ISE by considering basics on semiconductor physics. From simulations results we have found that are needed three stages in order to supply the needed current and voltage