Integrated Systems for Biomedical Applications: Silicon-Based RF\/Microwave Dielectric Spectroscopy and Sensing

Due to their use in the medical, biomedical, and nutritional fields, microwave dielectric sensors and spectroscopy systems are very good candidates for a variety of fields, including health care, food and drug safety, medical diagnosis, and agricultural and pharmaceutical applications. Dielectric sensors for such applications require fully integrated and self-sustained sensor implementations to achieve low-cost, compact, easy-to-handle products. Fully integrated dielectric sensors are promising (but also pose challenges) in terms of achieving size and cost reduction, low power consumption, enormous signal processing capabilities, and high throughput for portable, implantable, and lab-onchip applications. Integrated sensors can be either VCO-based, known for higher sensitivity and self-sustainability but not suitable for spectroscopy; or receiver-based, known to be more compatible with spectroscopy applications but with accuracy limited by the receiver's SNR performance. Given the challenges and design requirements for fully integrated dielectric sensors and spectroscopy systems, in this article we have summarized recently reported studies in the literature and shown in detail the advantages and disadvantages of each by comparing the different techniques.