Proceedings of the KIEE Conference (대한전기학회:학술대회논문집)
- 2009.07a
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- Pages.1515_1516
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- 2009
Development of a Wireless, Battery-free SAW-based Temperature and Humidity Sensor incorporating a Bidirectional Reflective Delay Line
양방향 반사 지연선을 이용한 무선, 무전원 SAW 기반 온, 습도 센서 개발
- Lim, Chun-Bae (Department of Electronics Engineering, Ajou University) ;
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Lee, Kee-Keun
(Department of Electronics Engineering, Ajou University)
- Published : 2009.07.14
Abstract
A 440MHz wireless and passive surface acoustic wave (SAW) based micro-sensor was developed for simultaneous measurement of temperature and humidity. The developed sensor is composed of a SAW reflective delay lines structured by an IDT (Inter-Digital Transducer), four reflectors and humidity sensitive film (polyimide). Polyimide was dry-ecthed by RIE (Reactive Ion Etching) to obtain high roughness, which gives the large reaction area resulting in high sensitivity. In wireless testing using a network analyzer, sharp reflection peaks with high S/N ratio, small signal attenuation, and few spurious peaks were observed in the time domain. High sensitivity towards the temperature and humidiy were also observed in the large concentration range. The obtained sensitivity was
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