RF-MEMS Technology for High-Performance Passives (Second Edition) - 5G applications and prospects for 6G

The focus of this book develops around hardware, and in particular on low-complexity components for Radio Frequency (RF) applications. To this end, microsystem (MEMS) technology for RF passive components, known as RF-MEMS, is employed, discussing its potentialities in the application frame of 5G. The approach adopted is practical, and a significant part of the content can be directly used by scientists involved in the field, to put their hand on actual design, optimization and development of innovative RF passive components in MEMS technology for 5G and beyond applications. This update (which includes a review of the main approaches to the modelling and simulations of MEMS and RF-MEMS devices) is timely and will find a wider readership as it crosses into the translational aspects of applied research in the subject. Key features • With over 50 pages of new content, the book will be 1/3 larger than the 1st edition. • New chapter on simulation and modelling techniques. • Practical approach to the design and development of RF-MEMS design concepts for 5G and upcoming 6G. • Includes case studies. • Video figures. • Includes a review of the business landscape

A Fully Parameterized Fem Model for Electromagnetic Optimization of an RF Mems Wafer Level Package

In this work, we present a fully parameterized capped transmission line model for electromagnetic optimization of a wafer level package (WLP) for RF MEMS applications using the Ansoft HFSS-TM electromagnetic simulator. All the degrees of freedom (DoF's) in the package fabrication can be modified within the model in order to optimize for losses and mismatch (capacitive and inductive couplings) introduced by the cap affecting the MEMS RF behaviour. Ansoft HFSS-TM was also validated for the simulation of capped RF MEMS devices by comparison against experimental data. A test run of capped 50 transmission lines and shorts was fabricated and tested.Comment: Submitted on behalf of EDA Publishing Association (http://irevues.inist.fr/EDA-Publishing

Parasitic Effects Reduction for Wafer-Level Packaging of RF-Mems

In RF-MEMS packaging, next to the protection of movable structures, optimization of package electrical performance plays a very important role. In this work, a wafer-level packaging process has been investigated and optimized in order to minimize electrical parasitic effects. The RF-MEMS package concept used is based on a wafer-level bonding of a capping silicon substrate to an RF-MEMS wafer. The capping silicon substrate resistivity, substrate thickness and the geometry of through-substrate electrical interconnect vias have been optimized using finite-element electromagnetic simulations (Ansoft HFSS). Test structures for electrical characterization have been designed and after their fabrication, measurement results will be compared with simulations.Comment: Submitted on behalf of TIMA Editions (http://irevues.inist.fr/tima-editions

Macromodel-based simulation and measurement of the dynamic pull-in of viscously damped RF-MEMS switches

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Low-temperature thin film encapsulation for MEMS with silicon nitride/chromium cap

In this work, a low-temperature fabrication process of thin film encapsulation (TFE) with silicon nitride/chromium cap is proposed for large-size (750 μm x 300 μm) packaging of microelectromechanical systems (MEMS). A FEM model was developed to evaluate the shape of TFE as a function of the residual stress and the thickness of the sealing layer, providing useful guidelines for the fabrication process. The low temperature of 200 °C, which was used in the plasma-enhanced chemical vapor deposition of the silicon nitride capping layer, allowed an organic sacrificial material to be employed for the definition of the encapsulation area. Silicon nitride/chromium (1 μm/20 nm) bilayer was demonstrated to be successful to overcome the technological limitations that affect the creation of cap holes with size of ~2 μm on high topography substrates, as in the case of MEMS. Plasma focused ion beam (PFIB) and scanning electron microscopy (SEM) techniques were used in combination to gain deeper insight into the sealing process of cap holes. Specifically, a PFIB-SEM serial section procedure was developed, resulting to be a powerful tool to directly observe the sealing profile above cap holes. Hence, the presented results greatly contribute to overcome the main technological/reliability issues of TFE, paving the way for the widespread application of the proposed encapsulation methodology to the most used MEMS devices, as radio-frequency (RF) switches, transducers, actuators, sensors and resonators

Experimental investigation on the exploitation of an active mechanism to restore the operability of malfunctioning RF-MEMS switches

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Modeling and Simulation of a TFET-Based Label-Free Biosensor with Enhanced Sensitivity

This study discusses the use of a triple material gate (TMG) junctionless tunnel field-effect transistor (JLTFET) as a biosensor to identify different protein molecules. Among the plethora of existing types of biosensors, FET/TFET-based devices are fully compatible with conventional integrated circuits. JLTFETs are preferred over TFETs and JLFETs because of their ease of fabrication and superior biosensing performance. Biomolecules are trapped by cavities etched across the gates. An analytical mathematical model of a TMG asymmetrical hetero-dielectric JLTFET biosensor is derived here for the first time. The TCAD simulator is used to examine the performance of a dielectrically modulated label-free biosensor. The voltage and current sensitivity of the device and the effects of the cavity size, bioanalyte electric charge, fill factor, and location on the performance of the biosensor are also investigated. The relative current sensitivity of the biosensor is found to be about 1013. Besides showing an enhanced sensitivity compared with other FET- and TFET-based biosensors, the device proves itself convenient for low-power applications, thus opening up numerous directions for future research and applications

Triangular Sierpinski Microwave Band-Stop Resonators for K-Band Filtering

Triangular resonators re-shaped with Sierpinski geometry were designed, manufactured, and tested for potential applications in the K-Band. Prototypes of band-stop filters working around 20 GHz and 26 GHz, interesting for RADAR and satellite communications, were studied in a coplanar waveguide (CPW) configuration. Single and coupled structures were analyzed to give evidence for: (i) the tuning of the resonance frequency by increasing the internal complexity of the triangle and (ii) resonance enhancement when coupled structures are considered. The exploited devices were part of the more extended family of metamaterial-inspired structures, and they were studied for their heuristic approach to the prediction of the spectrum using experimental results supported by electromagnetic simulations. As a result, a Sierpinski resonator, not only fed into but also fully embedded into a CPW environment, had a frequency response that was not easily determined by classical theoretical approaches

MEMS-Switched Triangular and U-Shaped Band-Stop Resonators for K-Band Operation

Triangular resonators re-shaped into Sierpinski geometry and U-shaped resonators were designed, linking them with single-pole-double-through (SPDT) RF MEMS switches to provide frequency tuning for potential applications in the K-Band. Prototypes of band-stop narrowband filters working around 20 GHz and 26 GHz, interesting for RADAR and satellite communications, were studied in a coplanar waveguide (CPW) configuration, and the tuning was obtained by switching between two paths of the devices loaded with different resonators. As a result, dual-band operation or fine-tuning could be obtained depending on the choice of the resonator, acting as a building block. The studied filters belong to the more general group of devices inspired by a metamaterial design

Interweaving temporal qualitative comparative analysis with necessary conditions analysis: an empirical application in the european monitoring systems context

There are very few empirical applications of Temporal Qualitative Comparative Analysis (TQCA). By interweaving TQCA with the necessary condition analysis stepwise procedure, I endeavour to compare instances of cheating and non-cheating practices within the European Social Fund context and unravel the multiple sequences of events leading to the outcome of interest. Implications for theory and practice are discussed by shedding a new light on the non-trivially necessary causes for both cheating and non-cheating activities