TRL Calibrated Coplanar Microwave Sensor for Characterization of Biomolecules

Abstract

In this paper, a coplanar microwave sensor is proposed to detect the biomolecules in aqueous solution. The proposed coplanar sensor is imprinted on the ground plane of the microstrip line, while microstrip to coplanar waveguide transition is achieved using via. The proposed design is highly compatible for study of the broadband electromagnetic properties of biological sample in the laboratory. A custom-designed thru-reflect-line approach is used for calibration of the vector network analyzer. The proposed microwave sensor is designed, fabricated and tested with various concentrations (50, 100, and 150 mg/mL) of a -amino acid viz. L-cysteine, which is an important stabilizing and redox active residue common in many proteins, in the frequency range of 500 MHz - 6.5 GHz.