Novel Simplified Model for Planar Capacitors up to 1 GHz

TL;DR

This paper introduces a new simplified model for planar capacitors operating up to 1 GHz, accounting for high-frequency effects, parasitic inductance, and losses, with experimental validation showing improved accuracy.

Contribution

A novel simplified planar capacitor model that includes substrate and medium effects, parasitic inductance, and losses, validated against existing models and physical measurements.

Findings

Model shows significant accuracy improvements

Good agreement with experimental data

Effective up to 1 GHz

Abstract

The study and modelling of planar capacitors remain highly relevant due to their broad applications. However, their accurate modelling presents significant challenges due to intrinsic high-frequency effects, which include not only parasitic inductance but also ohmic losses in the copper and dielectric losses in the substrate. Therefore, this work proposes developing a new simplified planar capacitor model consisting of two identical rectangular plates, which incorporates the effects of both the substrate and the medium between the conductor traces on the total capacitance. Moreover, it includes the impact of parasitic inductance and losses associated with the copper and substrate. This study demonstrated the importance of modelling both the dielectric substrate and the inter-conductor medium, with results showing significant improvements in the proposed model's accuracy. Experimental validation through comparison with an already established model in the literature and physical planar capacitors revealed good agreement for most cases studied.