Improving controllability in RF-MEMS switches using resistive damping

An efficient way to control the impact velocity in order to achieve soft landing and fewer bouncing phenomena is the resistive damping. This control method is also referred as charge drive and presented for first time by Castaner and Senturia [1]. Under charge control the Pull-in phenomenon of the Constant Voltage controlled electrostatic actuators does not exist and if the current drive is ideal, any position across the gap is stable. The main reason for this behavior is that the electrostatic force applied is always attractive and independent of the remaining gap of the actuator. Charge drive control incorporating constant current sources is mostly preferred to extend the travel range of electrostatic micro-actuators [2], [3], [4], [5]. Nevertheless there are very few references in the literature about charge drive control on RF MEMS. Recently published work based on numerical simulations for capacitive RF-MEMS, [6] and [7] present a learning algorithm in order to reduce fabrication variability using resistive damping for the pull-down phase. Nevertheless none of them present any details on how to implement resistive damping and any results of such kind of applications. This work presents in detail the entire procedure in calculating the bias resistance of an RFMEMS switch controlled under resistive damping

Analysis and design of an all metal in line series ohmic RF MEMS switch for microwave applications

Copyright © 2010 IEEE. Reprinted from IEEE Conference Proceedings. This material is posted here with permission of the IEEE. Such permission of the IEEE does not in any way imply IEEE endorsement of any of Brunel University's products or services. Internal or personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution must be obtained from the IEEE by writing to [email protected]. By choosing to view this document, you agree to all provisions of the copyright laws protecting it.Abstract: - This paper presents the analysis, design and simulation of an all metal in line series ohmic RF MEMS switch. The proposed switch is indented to be used in the frequency range between DC and 10GHz. The switching characteristics of the proposed switch fulfill all the requirements as concerns loss, isolation, linearity, power handling and small size/power consumption. The specific design of the cantilever (hammerhead) and the distributed actuation force ensure the reliability and the controllability of the switch and the relatively simple design (all metal) the robustness and high fabrication yield

An ohmic RF MEMS switch for reconfigurable microstrip array antennas built on PCB

This paper presents the analysis, design and simulation of an ohmic RF MEMS switch specified for reconfigurable microstrip array antennas built on PCB via an integrated monolithic technology. The proposed switch will be used to allow antenna beamforming in the operating frequency range between 2.4GHz and 4GHz. This application requires a great number of these switches to be integrated with an array of microstrip patch elements. The proposed switch exhibits outstanding switching characteristics, following a relatively simple design, which ensures reliability, robustness and high fabrication yield

On the design of an Ohmic RF MEMS switch for reconfigurable microstrip antenna applications

This paper presents the analysis, design and simulation of a direct contact (dc) RF MEMS switch specified for reconfigurable microstrip array antennas. The proposed switch is indented to be built on PCB via a monolithic technology together with the antenna patches. The proposed switch will be used to allow antenna beamforming in the operating frequency range between 2GHz and 4GHz. This application requires a great number of these switches to be integrated with an array of microstrip patch elements. The proposed switch fulfills the switching characteristics as concerns the five requirements (loss, linearity, voltage/power handling, small size/power consumption, temperature), following a relatively simple design, which ensures reliability, robustness and high fabrication yiel

fUel-SAVing trip plannEr (U-SAVE): a product of the JRC PoC Instrument: Final report

Available tools for trip planning mostly rely on travel time and travel distance. Fuel costs, when taken into account, are based on simplified fuel consumption models and are usually independent from vehicle type and technology. Building on the work carried out by the Sustainable Transport Unit of the Joint Research Centre, European Commission, in developing (a.) CO2MPAS, the official tool supporting the WLTP/NEDC Correlation Exercise and allowing the back-translation of a WLTP test to the equivalent NEDC CO2 emission value during the type approval, and (b.) Green Driving, an interactive web-based tool allowing the estimation of fuel costs and CO2 emissions of individual car journeys on the basis of variables such as car segment, engine power, fuel type and driving style, the present project aimed at developing and proving the concept of a routing machine to be used when fuel consumption minimization is considered. Throughout the project a stand-alone off-board trip planner has been developed, the U-SAVE Desktop Version, while a smartphone application, the U-SAVE Navigation Application, is currently under the last development phase, and shall be used once completed as a low cost in-board navigation system. The tool has been extensively validated internally demonstrating both its capability to accurately estimate fuel and energy consumption via alternative trip options, and its capacity to provide a more efficient route when different from the shortest and/or fastest options. An open-access version of the tool is expected to become a reference instrument for private citizens who are concerned about their fuel consumption and a more efficient use of their vehicles, while a premium API-based commercial version of the tool can operate as a viable and scalable business model targeting, among others, established navigation software providers who want to extend their offering by providing an alternative route option to their clients, mainly private companies managing fleets of light-duty vehicles, for whom saving fuel from the daily vehicle operations is of crucial financial importance.JRC.C.4-Sustainable Transpor

Study of four-storey steel buildong of offices

141 σ.Η παρούσα διπλωματική εργασία αφορά την μελέτη ενός νεόυ τετραόροφου μεταλλικού κτιρίου γραφείων. Το συγκεκρίμενο κτίριο επιλέχθηκε διότι παρουσίαζει ορισμένες ιδιομορφίες λόγω του σχήματος του.Είναι μη κανονικό σε κάτοψη και καθ’ύψος,ενώ σε ένα τμήμα του έχουν αφαιρεθεί ορισμένα υποστυλώματα από τον Α’ και Β’ όροφο δημιουργώντας ανοίγματα 16.00 m προκαλώντας έτσι αυξημένες απαιτήσεις ως προς τις διατομές. Η έλλειψη συμμετρίας καθώς και η μη κανονικότητα συνέβαλαν στην ανομοιομορφία ως προς την καταπόνηση του φορέα.Τα σεισμικά μεγέθη κατά την διεύθυνση x-x παρουσιάζονται σαφώς μεγαλύτερα σε σχέση με αυτά της διεύθυνσης y-y.Επιπλέον από τα αποτελέσματα της μελέτης προκύπτει οτί το κρίσιμο μέγεθος σε σχέση με την διαστασιολόγηση των στοιχείων του φέροντος οργανισμού είναι η συνολική ευστάθεια του κτιρίου. Η μελέτη έγινε σύμφωνα με τους αντίστοιχους Ευρωκώδικες.Πιο συγκεκριμένα: Ευρωκώδικας 0 - Βάσεις Σχεδιασμού Ευρωκώδικας 1 - Δράσεις επί των Κατασκευών Ευρωκώδικας 3 - Σχεδιασμός Κατασκευών από Χάλυβα Ευρωκώδικας 8 - Αντισεισμικός Σχεδιασμός ΚατασκευώνThe present thesis deals with the structural study of a new four storey steel building of offices. The specifi building was chosen since it has some peculiarities due to its shape.It is non regular both in plan and in elevation,while in one part of it some columns have been deleted from the 1st and 2nd floor creating openings of 16.00 m length,causing therefore higher demands in terms of section selection. The lack of symmetry in plan and the non-regularity have contributed in the uneven loading of the building.Seismic loads in x-x direction are clearly bigger than those in the y-y direction.Moreover,from the results of the structural study we can see that the critical element in terms of section selection is the overall stability of the building The study has been done according to the appropriate Eurocodes.More specifically: Eurocode 0 - Basis of structural design Eurocode 1 - Actions on Structures Eurocode 3 - Design of Steel Structures Eurocode 8 – Design of structures for earthquake resistanceΚωνσταντίνος Ι. Τσιακμάκης

An easy to control all-metal in-line-series ohmic RF MEMS switch

Copyright @ 2010 Springer-VerlagThe analysis, design and simulation of a novel easy to control all-metal in-line-series ohmic RF MEMS switch is presented, for applications where the operating frequency ranges from DC to 4 GHz. The proposed switch, due to its unique shape and size, assures high isolation and great linearity fulfilling the necessary requirements as concerns loss, power handling and power consumption. Simplicity has been set as the key success factor implying robustness and high fabrication yield. On the other hand, the specially designed cantilever-shape (hammerhead) allows distributed actuation force ensuring high controllability as well as reliability making the presented RF MEMS switch one of its kind

The interpretation of plural mass nouns in Greek

Altres ajuts: Acord transformatiu CRUE-CSICThis paper focuses on the interpretation of what has been considered an expletive marker in the grammar of the Greek nominal domain: the plural number of mass nouns. We present the results of an experimental investigation on the interpretation of plural mass nouns by native speakers of this language, and we propose a speech act analysis according to which at the time of producing utterances that contain plural mass nouns the speaker performs two speech acts: an assertion and an expressive speech act by which (s)he publicly commits to an emotive stance of dislike towards the expressed proposition φ. This stance is analyzed as an emotive judgment with respect to φ, the expression of which directly transfers the speaker's emotion from the conversation into the speaker and addressee's common ground

Analog interface based on capacitance multiplier for capacitive sensors and application to evaluate the quality of oils

Currently, interdigital capacitive (IDC) sensors are widely used in science, industry and technology. To measure the changes in capacitance in these sensors, many methods such as differentiation, phase delay between two signals, capacitor charging/discharging, oscillators and switching circuits have been proposed. These techniques often use high frequencies and high complexity to measure small capacitance changes of fF or aF with high sensitivity. An analog interface based on a capacitance multiplier for capacitive sensors is presented. This study includes analysis of the interface error factors, such as the error due to the components of the capacitance multiplier, parasitic capacitances, transient effects and non-ideal parameters of OpAmp. A design approach based on an IDC sensor to measure the quality of edible oils is presented and implemented. The quality relates to the total polar compounds (TPC) and consequently to relative electrical permittivity ${\varepsilon }_{r}$ of the oils. A measurement system has been implemented to measure the capacitance of the IDC sensor, which depended on ${\varepsilon }_{r}$. The simulation and experimental results showed that, for a capacitance multiplication factor equal to 1000, changes of 3.3 µs/100 fF can be achieved with an acceptable level of noise, which can be easily measured by a microcontroller