Techniques to Improve the Performance of Planar Microwave Sensors: A Review and Recent Developments

Planar microwave sensors have become increasing developed in recent decades, especially in material characterization (solid/liquid) as they provide regions highly sensitive to the surrounding medium. However, when it comes to deciphering the content of practical biological analytes or chemical components inside a host medium, even higher sensitivities are required due to their minute concentrations. This review article presents a comprehensive outlook on various methodologies to enhance sensitivity (e.g., coupling resonators, channel embedding, analyte immobilization, resonator pattern recognition, use of phase variation, using coupled line section, and intermodulation products), resolution (active sensors, differential measurements), and robustness (using machine learning) of arbitrary sensors of interest. Some of the most practical approaches are presented with prototype examples, and the main applications of incorporating such procedures are reported. Sensors with which the proposed techniques are implemented exhibit higher performance for high-end and real-life use.

Automated summary

This review article provides a comprehensive outlook on various methodologies to enhance the sensitivity, resolution, and robustness of arbitrary microwave sensors. Practical approaches with prototype examples are presented, and the main applications of these procedures are reported. Sensors implementing the proposed techniques show higher performance for high-end and real-life use.