An analysis of plate surface roughness effect for AT-cut resonators

This paper describes the theoretical analysis regarding the resonance frequency and electrical equivalent circuit constants characteristics vs. plate surface roughnesses for the AT-cut resonators which are adsorbing and without adsorbing for relative humidity. A new electric equivalent circuit theory was proposed, and the experimental proof was conducted by means of both the impedance analyzer and network analyzer measuring systems. Our theory was agreed with experimental results. This paper describes the experimental results on the plate roughness effect of relative humidity on the AT-cut quartz humidity sensors. This research was conducted to investigate principally the mechanism with respect to the resonance frequency changes influenced by relative humidity change etc. (including the impedance changes and equivalent circuit constant fluctuations) for the above humidity sensors.