Electromagnetic interference suppression and simultaneous switching noise mitigation in system on package using a lowpass filter structure with embedded capacitor

Abstract

System on package (SOP) is an emerging technology, and provides an implementation options for system with small size, especially for mixed-signal systems. However, in such a compact package, noise generated by the digital chip can be easily coupled to the RF IC, and degrade the sensitivity of RF signal. In this paper, a simple and efficient multi-order lowpass filter for EMI and SSN suppression in system on package is implemented with embedded capacitor material. It has good performance in noise isolation with a small size of 10mm×mm. The lowpass filter is designed and simulated by electromagnetic analysis software, HFSS. The insertion loss is below −70dB from1.5GHz to 10GHz. Then, the lowpass filter is serial with a surface mounted 47nH inductor, and can achieve noise suppression below-50dB from 50MHz to 10GHz, below −60dB from 140MHz to 10GHz, and below −80dB from 600MHz to 10GHz. That is very promising for system on package application in mixed-signal systems. The structure can also be used in large scale backplanes or motherboards.