A Novel Passive Wireless Humidity Sensor Based on a Dual-Metal Inductor

This paper describes a wireless, passive humidity sensor, based upon an inductor-capacitor circuit. An inductor with a dual-metal structure is employed to reduce the size of the chip and decrease the complexity of the process. This paper analyzes the shortcomings of conventional sensors and gives a novel structure to overcome these disadvantages, and also use ADS to simulate and verify the feasibility of the new structure. Finally this paper presents a detail fabrication process of this novel sensor. According to the wireless applications, the LC resonant frequency of the LC circuit was designed at 30 ~ 150 and 350~450MHz.