A 60 GHz Ring Sensor with Differential Feed-lines for Dielectric Spectroscopy in Biomedical Applications

A resonant sensor is an important tool to distinguish minute changes in dielectric permittivity of a sample. Low changes in permittivity are characteristic to physiological parameters such as body glucose levels, sputum analysis, cell characterization and so on. This work presents the design, simulation and measurement results of a resonant sensor for dielectric spectroscopy in biomedical applications. A 60 GHz ring sensor for differential feed-lines in reflecto-metric read-outs is presented along with measurements using DI-water, methanol, and dimethylsulphoxide (DMSO). A shift in the sensor's center frequency is observed along with the change in the quality factor of its input reflection coefficient.