RFID Portable System For Sensing Applications

This paper presents a RFID readout portable system aimed at sensing applications. The device is able to read chipless tags based on LC tanks, whose resonance frequency is modified due to a capacitance change caused by the parameter to be measured. A new approach in the reading process is presented based on a PLL which allows higher precision measurements. To test the performance of the designed device a printed and flexible tag has been used, which opens the door to a wide variety of applications where reading printed antennas is a need.