An Electromagnetic Bandgap Structure Integrated With RF LNA Using Integrated Fan-Out Wafer-Level Package for Gigahertz Noise Suppression

This paper presents a periodic electromagnetic bandgap (EBG) structure in the integrated fan-out wafer-level package (InFO-WLP) technology for gigahertz-band noise suppression. The proposed EBG structure consists of an LC resonator with two symmetrical spiral inductors in series and a shunt metal-insulator-metal capacitor between power and ground planes. The third-order equivalent model of the EBG structure is also proposed and extracted by field solver ANSYS Q3D to model the performance. In addition, the EBG arrays with different sizes of unit cell and the corresponding stopband bandwidth and isolation were characterized. The measurement results show that the proposed 1×4 EBG array of 600-μm square unit cell can achieve a 29.5-GHz stopband bandwidth together with an over 30-dB isolation level. Furthermore, by using the InFO-WLP technology, the proposed EBG structure is integrated with an RF low-noise amplifier (LNA) fabricated in a 16-nm FinFET technology as a case study to validate the power noise immunity. The experimental results show that the measured output spectrum of LNA integrated with the proposed EBG structure at the power plane can suppress the noise tone from -37.37 to -68.65 dBm.