Summary
International Symposium on Antennas and Propagation
2008
Session Number:2SS01c
Session:
Number:2SS01c-1
Injection-Locked-Based BPSK Demodulator in RFID Tag
Yu-Tsung Lo, Chi-En Liu, Jean-Fu Kiang,
pp.-
Publication Date:2008/10/27
Online ISSN:2188-5079
Summary:
PSK modulation is not usually used in the downlink (reader to tag) of typical RFID systems mainly because PSK demodulation takes a more complex detection scheme than ASK [1]. On the other hand, the PSK modulation becomes a good candidate in the uplink (tag to reader) because of its higher data rate and higher resilience against noise. A power-efficient tag with BPSK modulator has been proposed [2]. For the reader, although power is a less stringent constraint compared to tags, a low power system is still preferred, especially implemented in wireless technology. In this paper, a power-efficient BPSK demodulator is proposed in which non-coherent detection and injection-locked BPSK-to-ASK transform are adopted. No mixer, PLL or ADC is required, thus the circuit complexity is significantly reduced as compared to coherent detection scheme.