Planar Microwave Sensors: State of the Art and Applications

This review paper focuses on the latest advances and applications of planar microwave sensors contributed by the most prominent researchers in the field. The paper presents the different working principles, design approaches, fabrication technologies, materials, and applications of a wide variety of planar sensors operating at microwave and millimeter-wave frequencies, including contact and contactless sensors, wired and wireless sensors, microfluidic sensors, “green” sensors, wearables, biosensors, physical sensors, chemical sensors, and more. Advanced techniques for sensor performance optimization (e.g., sensitivity, resolution, selectivity, etc.), based on artificial intelligence, active feedback loops, microwave spectroscopy, losses engineering, etc., will also be discussed in the paper.