Custom PXIe-567X-Based SAW RFID Interrogation Signal Generator

Abstract

This paper presents a fully reconfigurable and reliable PXIe-567X software-defined interrogation signal generator for surface acoustic wave (SAW)-based passive radio frequency identification (RFID). 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 902–928 MHz and 2.45-GHz industrial scientific and medical bands. The PXIe-567X-based signal generator can accurately generate not only conventional ON–OFF keying (OOK)-modulated or pulsed binary phase shift keying (BPSK)-modulated SAW RFID interrogation signals, but also completely user-defined interrogation signals. A custom LabVIEW user interface that allows to control the carrier frequency, the power, and the waveform of the interrogation signal has been designed. The operator can switch between custom waveforms without resetting and reprogramming the whole system. The proposed RFID request signal generator has been validated using a complete measurement setup. Time-domain and frequency-domain validation tests of OOK modulated and wideband pulsed BPSK-modulated signal generation have been conducted at 170, 340, 915 MHz and 2.45 GHz. Very accurate results have been obtained. The PXIe-567X-based RFID interrogator has been tested with a fabricated 3-b SAW RFID tag. The operability of the entire SAW RFID system has been demonstrated.