High-Q factor of split ring resonator defected ground structure of microwave sensor for material characterization

• मुख्य लेखक: Mohammed Ba Amer, Rayan Ahmed
• स्वरूप: थीसिस
• भाषा: अंग्रेज़ी; अंग्रेज़ी
• प्रकाशित: 2025
• विषय: T Technology; TK Electrical engineering. Electronics Nuclear engineering
• ऑनलाइन पहुंच: http://eprints.utem.edu.my/id/eprint/29008/1/High-Q%20factor%20of%20split%20ring%20resonator%20defected%20ground%20structure%20of%20microwave%20sensor%20for%20material%20characterization%20%2824%20Pages%29.pdf; http://eprints.utem.edu.my/id/eprint/29008/2/High-Q%20factor%20of%20split%20ring%20resonator%20defected%20ground%20structure%20of%20microwave%20sensor%20for%20material%20characterization.pdf

Material characterization technologies require high accuracy sensors to meet the industrial specification in producing a reliable and safe product for human use. The existing microwave sensors using conventional microwave resonator such as waveguide, dielectric, and coaxial resonators have been used to characterize materials because they offer a high-quality factor (Q-factor) and great precision. However, they have a complicated structure and process, large and expensive to build. Recently, the planar resonant methods have become the most preferred approach because their simple structure and easy fabrication process. However, the low Q-factor value of this method cause a poor sensitivity and limit its applications. To overcome the limited quality factor, this project integrates the defected ground structure (DGS) technique into the split ring resonator (SRR) Microwave sensor to present new structures of high Q-factor microwave sensors based on defected ground structure split ring resonator (DGS SRR) for detecting and characterizing solid materials. This proposed sensor operated at 2.4 GHz where the solid samples characterization range resonate at 2.0 to 2.5 GHz with reference design SRR sensor operate at 2.5 GHz. The sensors were fabricated using RT/Duroid Roger 5880 as the substrate, characterized by a dielectric constant of 2.2, a loss tangent of 0.0009, and a copper thickness of 17.5 µm. The samples are placed at the maximum concentration of electrical field (E-Field) area where the maximum E-field area is the most sensitive area to observe the dielectric changes. The sensors are designed using computer simulation technology (CST) software and examined with a vector network analyzer (VNA). The resonator structure design is based on the mathematical equation and optimization of the parameters value. As a result, the DGS implementation has increase the Q-factor significantly from 190 to 357 this DGS SRR sensor generates narrow resonance frequency at 2.408 GHz with return loss equal to -17.54 dB. For validation, various solid materials have been used such as RO5880, RO4350 and FR-4 with dielectric constant equal to 2.2, 3.48 and 4.4 respectively. In addition, a detailed dielectric property analysis has been carried out in order to derive a mathematical equation to extract and characterize the materials with unknown dielectric properties. This sensor suits the need of various industrial applications such as the food industry, quality control, bio-sensing medicine, and pharmacy applications due to its capability to identify material characteristics with high Q-factor.