Custom PXIe-567X software defined interrogation signal generator for surface acoustic wave based passive rfid

This paper presents a fully reconfigurable and reliable NI-PXIe based RFID interrogation signal generator for passive wireless SAW sensors. Contrary to most commercial SAW RFID readers that operate only at a unique predefined frequency, the proposed Vector Signal Generator is aimed to operate at any frequency defined by the user, from 85 MHz to 6.6 GHz, including the 2.45 GHz ISM band. A custom LabVIEW user interface has been designed to control the PXIe-567X based system; allowing to set the carrier frequency, the power and the waveform of the interrogation signal. The user can switch between custom waveforms without resetting and reprogramming the whole system. The proposed software defined RFID interrogation signal generator has been validated using a complete measurement setup. Measurements have been conducted for OOK and wideband pulsed BPSK signals modulated at 340 MHz and 2.45 GHz. Accurate results have been obtained for different periodic pulse signals at different frequencies.