Characterization of Thin Film Enabled Engineered Substrate for RF Applications

Engineered substrate enabled by Permalloy (Ni
₈₀
Fe
₂₀
, Py) thin films has been well developed for RF applications with high and tunable permeability and moderate loss. A full investigation on the characteristics of the engineered substrate is presented in this paper. The loss and equivalent permeability generated by the Py patterns are characterized through a microstrip line model. Multiple factors of Py patterns are taken into consideration to define the performance of the engineered substrate, including filling density, thickness, dimensions, and locations. The analytical results give a detailed guideline for the design of engineered substrate.