| 초록 |
Relative humidity (RH) is an important environmental parameter along with temperature to assess the quality of air, and polyvinyl alcohol (PVA) has been used in microwave frequencies as a high-sensitivity polymer material for RH sensing. In this paper, the effect of film thickness on the sensitivity for a PVA-based microwave humidity sensor was investigated. A high-sensitivity meander-line slot (MLS)-loaded microstrip patch sensor antenna (MPSA) was designed and fabricated on a 0.76 mm-thick RF-35 substrate to resonate at 2.5 GHz under unloaded conditions. Three different PVA films with different thickness were coated on top of the MLS resonator of the MPSA, and their sensitivities for varying RH from 40% to 80% with a step of 10% were compared, by measuring the shift in the resonant frequency of the input reflection coefficient characteristic. |
