This paper presents the design of a power harvester for passive RFID Tags. An impedance matching circuit chooses a high-pass L network inserted between the antenna and rectifier circuit to maximize the power transferred to Tags using an impedance transformation technique. A simple circuit including only a shunt inductance was selected as a matching. The rectifier utilizes a Self-Vth-Cancellation (SVC) circuit is an archived self-threshold voltage cancellation and self-power regulation function with a simple circuit design. An antenna is modeled as an RF source with a series impedance Zs of 50Ω while the rectifier is modeled as a load impedance ZL which is estimated from the process and design parameters of the NMOS and PMOS transistors used in the SVC rectifier. As the combined circuit was simulated using input in the UHF band of 953 MHz and the devices’ model of the 0.35μm CMOS technology. The simulation results were compared with the single-stage rectifier of the SVC technique in the issue of the Power Conversion Efficiency (PCE). The achieved DC output of the rectifier yields the power conversion efficiency of 43.7% at input RF power -10.22dBm while a DC output voltage of around 643.8mV and a current load of 64.4μA.

This project aims to develop RFID reader. With the following scope can scan at least 15 cards save both entry and exit data display Welcome on the screen and add or reduce codes by yourself The test results show that the RFID scanner can scan both key cards and manually scan both in and out. The screen also shows Welcome when someone enters and shows thank you when someone shows that the developed scanner can be applied really slowly

In this paper the printed loop antenna is proposed for high frequency radio frequency identification (HF-RFID) systems (13.56 MHz). The proposed antenna is designed on the printed circuit board (PCB). The antenna structure consists of printed semi-spiral loop with rectangular structure patch at the middle of loop. It can provide the magnetic field distribution to cover the operating area with various directions that can improve the communication performance between reader and various tag orientations. From the measured results the proposed antenna has more efficient than the printed spiral loop antenna