Absorptive-Material-Based Structure for Suppressing Unwanted Radiation in Chip-Packages

Abstract

In this paper, a double-layer structured absorptive material for solving the electromagnetic radiation problems in chip-packages is proposed. This low-profile absorber structure is composed of two flat layers where the lower layer is made of absorbing material with high relative permittivity, while the upper layer is made of material with low relative permittivity to better meet the requirements of wide impedance matching. This structure is firstly designed based on theories and full-wave simulations. Then it is fabricated and applied to different absorbing materials working in the frequency range of 20-40GHz to suppress the radiation in a practical chip-package model. Finally, the effectiveness and universality of this structure are verified through measurements of the radiation suppression effect with different absorbing material settings.