Abstract
Using the network analyzer, we investigated electrical characteristics of printed circuit boards (PCBs) which consist of a coil-shaped conductor and two ground planes (top and bottom). We compared S-parameters for various types of PCBs with different shapes of the coiled conductors with and without Ni-Zn ferrite composite material. From the measured S11s, the equivalent inductances of the coiled conductors were evaluated. Furthermore, using the measured S-parameters, we evaluated the effective relative permeability and permittivity of the insulator inside of PCBs. We found that for the measured frequency range, it is needed to consider PCBs investigated as transmission lines and the equivalent inductances of the coiled conductors hardly depend on their shapes. Power was more absorbed in a PCB with Ni-Zn ferrite composite material than that without the composite material.
