A 24 GHz dielectric sensor based on distributed architecture

Abstract

In this paper, a dielectric sensor based on distributed architecture topology is presented. The measured sensor delivers the dielectric information as a notch frequency between 21 GHz to 25 GHz. The proposed sensor is intended to perform as a microwave dielectric sensor to identify biomaterials but can be used for other applications as well. It is fabricated in a standard 0.25 μm SiGe BiCMOS process with HBTs (f T /f max = 120/140 GHz) and it consumes 13.4 mW DC power. The sensor has been simulated and measured with different dielectric materials. For proof of concept, first experiments have been conducted for air, epoxy resin and honey. Owing to the distributed concept and the destructive interference, a sensitivity of 0.32 GHz per unit permittivity (1.35% of the center frequency) was achieved. Based on these permittivity measurements, the presented results illustrate that this technique is a promising solution for biomaterial sensing and characterization.