Dielectric Characterization Using Reflected Group Delay of Microstrip Ring Resonator

This paper presents a novel approach for dielectric characterization of microstrip boards utilizing the reflected group delay of a capacitively coupled ring resonator. The resonator is allowed to operate in an over-coupled state which enables the characterization over a broader frequency range as compared to the conventional critically coupled resonator techniques. Simulation results confirm its effectiveness in accurately determining dielectric constant within the range of 1.2 to 4.2, with an error of less than 1% and measuring loss tangent with an error under 70%. The proposed method is simple, efficient and adaptable, making it suitable for applications in both research and industrial environments.