摘要 |
Practical battery operation of radio-frequency proximity readers (12) in a t ag reader system (10) is made possible by monitoring activity in the RFID reader's sensing field (S) with a secondary detector (20) such as a passive infrared detector having an overlapping field of view (V), and powering up t he RFID reader only upon detection of activity by the secondary detector. The RFID reader is kept to a low duty cycle relative to the secondary detector which is chosen for relatively low power consumption to achieve a net reduction in operating power requirements of the combined RFID reader and secondary detector. |