논문 해외 국제전문학술지(SCI급) A self-sustained CMOS microwave chemical sensor using a frequency synthesizer
- 학술지 구분 국제전문학술지(SCI급)
- 게재년월 2012
- 저자명 AA Helmy, HJ Jeon, YC Lo, AJ Larsson, R Kulkarni, J Kim, Jose Silva-Martinez, Kamran Entesari
- 학술지명 IEEE Journal of Solid-State Circuits
- 발행처명 IEEE XPLORE
- 발행국가 해외
- 논문언어 외국어
홈페이지논문 초록 (Abstract)
In this paper, a CMOS on-chip sensor is presented to detect dielectric constant of organic chemicals. The dielectric constant of these chemicals is measured using the oscillation frequency shift of an LC voltage-controlled oscillator (VCO) upon the change of the tank capacitance when exposed to the liquid. To make the system self-sustained, the VCO is embedded inside a frequency synthesizer to convert the frequency shift into voltage that can be digitized using an on-chip analog-to-digital converter. The dielectric constant is then estimated using a detection procedure including the calibration of the sensor. The dielectric constants of different organic liquids have been detected in the frequency range of 7-9 GHz with an accuracy of 3.7% compared with theoretical values for sample volumes of 10-20 μL. The sensor is also applicable for binary mixture detection and estimation of the fractional volume of the constituting materials with an accuracy of 1%-2%.