Design of a Low-Power RFID Sensor System Based on RF Energy Harvesting and Anti-Collision Algorithm.

Area of Science:

• Electrical Engineering
• Computer Science
• Wireless Communication

Background:

• Passive Radio Frequency Identification (RFID) sensing systems combine wireless power transfer with data identification.
• Existing passive RFID systems face challenges including low RF energy harvesting efficiency, high sensor power consumption, and complex anti-collision algorithms.

Purpose of the Study:

• To propose a hardware-software co-optimized RFID sensor system to overcome the limitations of conventional passive RFID systems.
• To enhance RF-DC energy conversion efficiency, minimize sensor node power consumption, and simplify tag anti-collision mechanisms.

Main Methods:

• Hardware improvements include using low threshold RF Schottky diodes and an input inductor in the voltage multiplier rectifier to boost signal amplitude.
• A low-power management strategy is implemented for the sensor node's power supply and control logic.
• A Dual-Threshold Stepped Dynamic Frame Slotted ALOHA (DTS-DFSA) anti-collision algorithm is proposed, adaptively adjusting frame length based on collision ratio.

Main Results:

• The maximum RF-DC energy conversion efficiency increased from 60.56% to 68.69%.
• Sensor load current was reduced from approximately 2.0 mA (active) to 74 μA (idle), demonstrating effective power gating.
• The DTS-DFSA algorithm showed superior identification efficiency and lower computational complexity compared to existing low-complexity schemes.

Conclusions:

• The proposed hardware-software co-optimization significantly improves the performance of passive RFID sensing systems.
• The enhanced energy harvesting, low-power management, and efficient anti-collision algorithm address key practical challenges.
• The DTS-DFSA algorithm offers a viable solution for resource-constrained embedded platforms requiring efficient tag identification.