Application of Free Space Method in Measuring Dielectric Constant in PCB

In this paper, a device for measuring the dielectric constant of PCB boards is designed based on the scattering characteristics of electromagnetic waves by dielectric materials. The dielectric constant of PCB materials is determined by measuring the phase shift and resonance characteristics of the dielectric with respect to microwaves. This device enables noncontact, wideband, and open-ended measurements. Experimental results demonstrate that, within the allowable measurement error range, this testing method is simple and feasible.