Study of the Radio Frequency (RF) performance of a Wafer-Level Package (WLP) with Through Silicon Vias (TSVs) for the integration of RF-MEMS and micromachined waveguides in the context of 5G and Internet of Things (IoT) applications: Part 1—validation of the 3D modelling approach

Packaging of Radio Frequency MicroElectroMechanical-Systems (RF-MEMS) and other passive components is a delicate issue, especially in the riverbed of upcoming application contexts like 5G and the Internet of Things, in which frequencies of operation are getting closer to mm-Waves (millimetre waves). In fact, when dealing with RF signals, the package, beyond protecting encapsulated devices, has also to exert an influence as limited as possible on their electromagnetic characteristics and performance. Therefore, the package design phase has to be performed with particular care. Given such a frame of reference, this study discusses the validation against experimental data of a full-3D methodology for the electromagnetic simulation of a Wafer-Level Packaging solution featuring Through Silicon Vias for the redistribution of electrical signal from the in-package (RF-MEMS) passive devices to the external world. In particular, the results of the full-3D finite element method RF simulations will be compared against experimental S-parameters datasets for a certain variety of Coplanar Waveguide test structures, in a frequency range from 50 MHz up to 30 GHz, showing good accuracy in predicting the behaviour of physical devices. For the sake of brevity, this work will be followed by a standalone second part in which the full-3D model, here validated, will be parameterised and exploited to analyse the influence of the most relevant Degrees of Freedom available in the package design, on the RF characteristics of encapsulated RF-MEMS passive devices.