A Design of Modulator and Demodulator for a Passive UHF RFID Tag Using DTMOST Compatible with C1 G2 EPC Standard Protocol

Abstract

This paper presents a modulator and low power ASK demodulator that uses a new technique. This technique uses the dynamic threshold MOSFET to reduce the threshold voltage of diodes connected MOS transistors as a barrier in the design of the envelope detector. This circuit has been simulated in a 90 nm CMOS technology to satisfy EPC Class 1 Generation 2 standard protocol. The proposed circuit can correctly demodulate the minimum input power −20 dBm for a modulation index of 37–100 % with 40–160 kb/s data rates. The proposed technique has reduced energy consumption at 11.44 nW at 0.4 V, 27 °C. This will increase the operating range of the RFID tags.