A Power management scheme for wirelessly-powered RFID tags with inkjet-printed display

摘要

This work proposes a new power management scheme for wirelessly-powered UHF RFID tags with flexible inkjet-printed Electrochromic (EC) display for human-to-device interaction. EC display on polyimide substrate is integrated at tag side to provide an ambient and direct human-to-device display interface. An aggressive duty-cycling power management scheme with dual supplies is designed to drive the EC display under the tag power budget in microwatt level through RF energy harvesting. In this scheme, energy for display refreshing is accumulated over multiple power management cycles. A single-pixel addressing scheme with minimal pixel size is proposed to further reduce display power and improve tag sensitivity by exploiting EC display bi-stability. The experimental results show that the EC display can be refreshed with the tag sensitivity of -10.5 dBm at 11.7 sec/cm2 update rate.