Measurement of Dielectric Constant and Loss Tangent in High-Frequency Laminates with Practical Implementation Comparison

This paper designs methods for measuring key parameters of high-frequency circuit boards using simple circuits in experimental settings. Firstly, the effective dielectric constant of the dielectric in high-frequency laminates is measured using two fundamental experimental methods: the phase difference method and the resonance method. Subsequently, the dielectric loss tangent is determined using the same circuits with the theory of energy conservation or the quality factors obtained from the resonators. These methods were applied to an FR4 circuit board, 1 mm thick, with a dielectric constant and loss tangent provided by the manufacturer as 4.2 and 0.02, respectively. The results, showing changes with frequency up to 8 GHz, were compared and found to be consistent with our predictions, verifying the feasibility of our methods. These approaches can be utilized in general laboratory settings for the simple verification of high-frequency laminates and for obtaining laminate parameters that vary with frequency for more precise designs.