Compact Implementation of an RFID Tag with Electromagnetic Wave Polarization Diversity

The paper presents a backscattering RFID system with reduced interference of incident and reflected electromagnetic waves. The tag system is designed for 5 GHz operating frequency and uses two microstrip patch antennas with linear polarization in perpendicular directions. Between the tag antennas a block including a Schottky diode is used for amplitude modulation of the received signal with tag information. The tag is fabricated on a FR-4 double clad substrate and the measurements results are presented for different reading ranges.