Correlation of EMI measurements and simulations for simple package geometries

This paper presents three measurement- and one simulation-approaches to quantify radiation from IC-package geometries. Two test boards were built and measured by using a semi-anechoic chamber, GTEM cell and near-field scan. Good correlations were achieved between measurements and simulations. Advantages and limits of each approach were addressed.

INTRODUCTION

When microprocessors operated at hundreds of MHz, component packaging had little effect on EMI. With the advent of GHz CPU's and the promise of much higher frequencies in the not so distant future, component packaging takes the front seat in the theatre of EMI. Where before the package was electrically short relative to the operational frequency, the package can easily become an efficient antenna for GHz microprocessors and lead to significantly higher emissions. Package EMI is challenging because measurement and simulation methodologies are not well established. Four approaches can be applied to study package EMI: chamber, GTEM and near-field scan measurements, and numerical simulation.