Subject Area

Electrical, Electronics Engineering

Abstract

Nonionizing electromagnetic waves provide a noninvasive evaluation of biological tissues affected by dielectric property variations. The interactions of electromagnetic waves with tissues in different dielectric properties affect wave scattering. The tissue type and condition can be determined by evaluating resonant frequency shift and magnitude changes in reflection or transmission coefficients. Planar resonators provide a compact size and can be fabricated on monolithic, flexible substrates conforming to the skin, making it potentially wearable that can continuously monitor body functions in the long term. However, most planar resonators fail to provide sufficiently high-intensity field densities and spatial resolutions into the tissues due to their poor resonance at microwaves, suffering from low sensitivity. Additional dynamic matching circuits may achieve a high-quality factor but are bulky with design constraints, increase insertion losses, and limit resonance frequency ranges. It is challenging for wide-band impedance matching to achieve a high-quality factor in a conformal microwave resonator without losing the advantages of being small and planar. Targeting the challenges, my work developed a self-tuned method for impedance-matching. Based on this novel method, this work aims to develop biomedical sensing applications such as human hydration assessment, glucose level monitoring, subcutaneous tumor detection, vein finder, etc.

Degree Date

Summer 2024

Document Type

Dissertation

Degree Name

Ph.D.

Department

Electrical and Computer Engineering

Advisor

Jung-Chih Chiao

Second Advisor

Carlos E. Davila

Third Advisor

Behrouz Peikari

Fourth Advisor

Jianhui Wang

Fifth Advisor

Changzhi Li

Sixth Advisor

Yang Li

Number of Pages

231

Format

.pdf

Creative Commons License

Creative Commons Attribution 4.0 License
This work is licensed under a Creative Commons Attribution 4.0 License.

Available for download on Monday, July 30, 2029

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