Dual-Band Passive BLE Backscatter Tag With Clock-Coordinated Modulation

The large-scale deployment of Internet of Things (IoT) nodes has made low power consumption and high device compatibility key issues. The prevailing communication protocol for passive IoT devices is ISO/IEC 18000-6C. However, this protocol can only be implemented on the business side via dedicated readers, limiting its popularity among consumers. Bluetooth Low Energy (BLE) is by far the most common type of connection. However, it requires a crystal oscillator to generate the necessary high-precision clock signal. For passive applications, using a crystal oscillator increases power consumption, cost and size. This paper addresses the integration of BLE uplink logic into RFID tag chips by providing a high-precision BLE clock via an air interface using clock-coordinated modulated wave technology. This enables passive IoT tags to access common consumer smart devices. A dual-band passive chip has been fabricated using the TSMC 0.18 μm process. The resulting device measures 1.24 mm², has an average power consumption of 16.4 μW and a communication range of 12.9 m.