Date Added: Nov 2011
Recently, interesting about RFID sensor tag technology which can obtain information on the external environment to smart card is increasing worldwide. In case of sensor tag, most of sensor tag has been developed as resistive type sensor tags. Resistive type humidity sensor requires temperature revision as the influence of temperature and there are special environment to detect low humidity of 15% or less. To solve this problem, circuit was composed that capacitive sensor is interlocked to resistive type sensor tag. The composed circuit is a capacitive humidity sensor which is connected to resistive sensor tags. Using the CVC circuit, capacitive humidity sensor change is output voltage. The output voltage connects with resistive sensor tag.