A Novel Passive Cost-Effective Technique to Improve Radiated Immunity on PCBs

This paper proposes a novel simple cost-effective technique to improve the potential immunity of integrated circuits (ICs) to radiated electromagnetic (EM) disturbances. It is based on dielectric loading which lessens the susceptibility of ICs independently of frequency by confining the reactive fields inside the dielectric load. This has no side effects on the IC performance. To highlight the importance of the proposed technique, immunity testing was performed numerically both in near and far fields. A loaded IC (a microcontroller) was compared to an unloaded one through far-field measurements inside a transverse EM cell to indirectly assess the suitability of the proposed approach. Results show that loading the IC with non-ferromagnetic dielectric material not only effectively decreases its susceptibility to electric field, but also to magnetic field. Moreover, a significant difference of $\sim$48% less failure rate was achieved for the loaded compared to the unloaded IC demonstrating the usefulness of this technique as a potential solution for radiated immunity improvement.

I. Introduction

Electromagnetic (EM) immunity (EMI) and EM compatibility (EMC) testing are of great importance with the fast increasing functionality and complexity of integrated circuits (ICs) [1]–[3]. A higher clock frequency or any electrical transition with sharp edges (e.g., addressing or controlling data) gives rise to EMI issues [4].