Research On Transmission Line Resonator For Moisture Sensing

Sensor works with the function changing the character of sample to the signal which can be easily detected by normal equipment. The micro-sensor is wild researched due to its advantage such as nondestructive, facility, easy integrate. One of its most important applications is moisture sensing. Water is a special material, since commonly its relative permittivity is 80, so the relative permittivity of material which contains water is seriously influenced by the moisture. Using this principle, we could sense the rate of water in sample.Moisture content in solid, granular and pulverized materials is one of the most important material parameters during production, trading, processing and storage of those materials. So the moisture sensing became more and more significant.Base on the research and analysis on many kinds of moisture sensing, the paper design a new moisture sensing: transmission line resonator. This new design works around the frequency of 2.24 GHz. And it has the advantage of eliminating the effect of temperature, besides it is also facility. The paper mainly has the content as follow.Firstly, paper analyses the resonator on the principle aspect, then divides the resonator into four function module. Including testing resonator, criterion resonator, jiggle and coupling system. They are all analyses in principle.Secondly, according to the principle, paper design the resonator concretely and setting the dimension of every function module. Then we simulate the design with HFSS which is famous 3D EM simulation software, in order to check our setting, and get a satisfied result.Finally, we make the resonator in practice and then test the resonator. The testing result is satisfied and proving that the design is correct completely.