Towards multi-sensing aspects: robust passive chipless RFID sensor tag

The work presents a passive battery-less chipless RFID tag for multi-sensing parameters. The tag designed for 1-bit data encoding, has been examined for humidity as well as temperature sensing simultaneously. The humidity sensing tag has been designed using Kapton HN substrate, along with copper electrode. The operational frequency of sensor tag is 11.25 GHz and temperature sensitive tag is 5.5 GHz. For monitoring temperature fluctuations in atmosphere, Rogers RT/Duroid 6010.2LM has been acquired as temperature sensitive substrate. To analyze the selectivity and sensitivity of temperature sensor tag, the slot of tag is coated with Kapton heat resistant sheet. Through simulations, it has been analyzed that the tag temperature sensing response is not affected by humidity variations in environment. The work is capable of being utilized for smart wireless sensor networks in industrial internet-of-things (IIoT).