Design of a transceiver RF front-end for 2.45 GHz RFID readers

In this paper, a system level design of a 2.45 GHz RFID reader transceiver front-end for the entire 2400-2483.5MHz RFID band supporting ISO 18000-4 standard is presented. Based on the physical layer parameters of the mentioned standard, and given required antenna gain, the transceiver architecture is chosen, designed and optimized for optimum sensitivity, linearity and noise figure using link budget simulation. A direct conversion architecture is adopted for the receiver for a high level of integration and low power consumption, while a double conversion architecture - based on a GMSK modulator - is used for the transmit chain. To validate the proposed system level design, practical building blocks from different RF/Microwave vendors are used to implement the transceiver. Link budget and envelope simulations are used to quantify the operation of the designed RFID reader. For a read range of 20m, and using a transmitted power of 27dBm, at a data rate of 384Kbit/s, the reader has a P_1dB of 5dBm, sensitivity of -95dBm, while achieving a noise figure of 4dB.