Review Article Volume 7 • Issue 4 123 Review on Microwave Surface Resistance of High Temperature Superconductor Yttrium Barium Copper Oxide (YBCO) Yam Prasad Dahal 1,2* , Bingfu Gu 1 , Rishi Ghimire 2 , Zhenping Su 1 , Yao Fu 1 Affiliation: 1 Beihang University (BUAA), 37 Xueyuan Rd, Haidian District, Beijing, China 2 Tribhuvan University, Kathmandu 46000, Nepal Corresponding author: Yam Prasad Dahal, Beihang University (BUAA), 37 Xueyuan Rd, Haidian District, Beijing, China, 100191. Citation: Yam Prasad Dahal, Bingfu Gu, Rishi Ghimire, Zhenping Su, Yao Fu. Review on Microwave Surface Resistance of High Temperature Superconductor Yttrium Barium Copper Oxide (YBCO). Journal of Radiology and Clinical Imaging. 7 (2024): 123-135. Received: November 20, 2024 Accepted: November 28, 2024 Published: December 17, 2024 Abstract The performance of Yttrium-Barium Copper Oxide (YBCO) high- temperature superconductors in high-frequency applications is significantly affected by the microwave surface resistance (Rs). The paper delves into the basics, measuring methods and factors affecting the resistance (Rs) in YBCO, highlighting its high critical temperature (Tc) and low resistance, positioning it as a promising material. YBCO's compatibility with epitaxial growth and microstructure engineering offers opportunities to reduce grain boundary effects and improve Rs, making it advantageous for high-frequency electronics as well as communication systems such as filters, resonators, antennas, and transmission lines. This is due to its high critical current density (Jc) and exceptional Rs at practical temperatures. Challenges remain in comprehending and managing Rs in YBCO, despite its favorable characteristics. Utilizing advanced fabrication methods and incorporating nanotechnology allow for customization of YBCO- based devices. Multi-scale modeling and simulation are essential for guiding experimental work and understanding YBCO's performance in high-frequency settings. This study highlights the promise of YBCO for future high-frequency technologies and stresses the importance of more research to overcome hurdles and fully exploit its capabilities, potentially transforming superconducting devices for practical use. Keywords: Microwave surface resistance; YBCO; Critical current density; Critical temperature. Introduction General Overview Superconductivity is a phenomenon that occurs in some materials when they are cooled below a critical temperature, resulting in the total elimination of electrical resistance [1]. This exceptional characteristic allows the material to transmit electricity without any loss, resulting in a variety of groundbreaking applications such as high-speed magnetic levitation trains and very sensitive magnetic resonance imaging devices [2,3]. Traditional superconductors, known as low temperature superconductors (LTS), were first found in the early 20th century and function at very low temperatures, usually close to absolute zero. The finding of high temperature superconductors (HTS) in the late 20th century generated significant enthusiasm and conjecture among scientists [4]. HTS materials display superconducting properties at much greater temperatures compared to traditional materials, even surpassing the boiling point of liquid nitrogen. This presents the exciting possibility of practical use under more convenient and cost-effective cooling conditions