National Research Council of Canada. National Institute for Nanotechnology
S-parameters and high resolution sensing; active device; liquid sensing; microwave passive resonator
A novel electromagnetic sensor operating at microwave frequencies with quality factor of 22,000 at 1.4 GHz for real-time sensing of fluid properties is presented. The core of the sensor has a planar microstrip resonator, which is enhanced using an active feedback loop. The resonance frequency and quality factor of the sensor show clear differentiation between analytes composed of common solvents. To evaluate the sensor for water based concentration detection, we have demonstrated that KOH dilutions as low as 0.1 mM are detectable. The proposed sensor has advantages of inexpensiveness and high resolution as well as capability for miniaturization and CMOS compatibility.
IEEE Microwave and Wireless Components Letters25, no. 9: 621–623.