This paper discusses the design of chip-less RFID tags of a standard pocket size of 69 mm by 156 mm. These tags are based on lumped elements of copper metal traces constructed on a thin polyamide flexible substrate. Moreover, a low-cost single-chip Bluetooth detector circuit system is demonstrated. Two different detection methods: variable coil load coupling and optical light intensity detection were combined to yield 256 unique ID codes. In the first method, by utilizing simple 4 MHz digital drivers and an integrated analog to digital converter (ADC) in the reader controller; various inductively coupled resonant loads corresponding to multiple distinct tags could be differentiated, yielding eight different (3-bit) ID codes. The additional via-based hole pattern reflectometer method creates additional 32 distinct levels (5-bit) utilizing 650 nm visible light-emitting diode and a simple trans-impedance operational along with the same analog ADC pins of a Bluetooth controller. The printed circuit board trace coil on the two-layer low-cost FR-4 waterproof sealed detector unit is simultaneously used as a Qi wireless power receiver to charge the120 mAh 2450 Lithium Polymer (LiR) battery. The device could remain operational for more than a month with a single charge; remaining connected with a mobile device and enabling 10 readouts daily.

中文翻译：

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低成本薄膜无源 RFID 电路和检测器系统

本文讨论了标准口袋尺寸为 69 mm x 156 mm 的无芯片 RFID 标签的设计。这些标签基于构建在薄聚酰胺柔性基板上的铜金属迹线的集总元件。此外，还展示了一种低成本的单片蓝牙检测电路系统。两种不同的检测方法：可变线圈负载耦合和光强检测相结合，产生 256 个唯一 ID 代码。在第一种方法中，通过使用简单的 4 MHz 数字驱动器和读卡器控制器中的集成模数转换器 (ADC)；可以区分对应于多个不同标签的各种电感耦合谐振负载，从而产生八个不同（3 位）的 ID 代码。额外的基于通孔的孔图案反射计方法利用 650 nm 可见发光二极管和一个简单的跨阻抗操作以及蓝牙控制器的相同模拟 ADC 引脚创建额外的 32 个不同级别（5 位）。两层低成本 FR-4 防水密封探测器单元上的印刷电路板迹线线圈同时用作 Qi 无线电源接收器，为 120 mAh 2450 锂聚合物 (LiR) 电池充电。该设备一次充电可保持运行一个多月；保持与移动设备的连接并每天启用 10 个读数。两层低成本 FR-4 防水密封探测器单元上的印刷电路板迹线线圈同时用作 Qi 无线电源接收器，为 120 mAh 2450 锂聚合物 (LiR) 电池充电。该设备一次充电可保持运行一个多月；保持与移动设备的连接并每天启用 10 个读数。两层低成本 FR-4 防水密封探测器单元上的印刷电路板迹线线圈同时用作 Qi 无线电源接收器，为 120 mAh 2450 锂聚合物 (LiR) 电池充电。该设备一次充电可保持运行一个多月；保持与移动设备的连接并每天启用 10 个读数。