Resonant Circuit Series, Coupled Magnetically, With Impedance Adaptation For RFID Devices

In the systems of "Identification for Radio Frequency” (RFID), constitutes a very important aspect the transmission of the biggest current quantity between the antenna receiver and the electronic scheme that constitute the receiver, fundamentally, and the efficiency with which this obtain. In the work a circuital variant is analyzed, tuned series and coupled inductively, in the receiver block, that improves this characteristic. Also it is described, shortly, the obtaining of the expression of the coupling capacity, between the adapting circuit and the load, that assures to obtain the maxim current for the load resistance. With this circuital version, it is guaranteed to obtain a bigger current in the load that the up to now obtained with the reported scheme in these devices RFID. Besides the efficiency improvement, it is possible to increase the receiver circuit selectivity respect to the schemes traditionally used, aspect also very interesting in some applications of this device type. The characterization and confirmation of the proposed scheme and the obtained results, they are carried out using simulation tools of “Matlab” and through of experimental measurements. Finally the experimental results are analyzed, they are compared with both simulation and theoretical, and the effectiveness of the proposed schemes is demonstrated, for to obtain the declared objectives.