Design criteria for the RF section of long range passive RFID systems

We have derived a set of consistent design criteria for the RF section of long range passive RFID transponders, operating in the 916 MHz and 2.45 GHz ISM frequency ranges. In particul.ar, we describe the design criteria for the voltage multiplier, for the power matching network between the antenna and the non linear circuit represented by the voltage multiplier, and for the modulator of the backscattered radiation. We discuss the various design tradeoffs and determine the regions of the design space that allow us to maximize the operating range of the RFlD system.