48 research outputs found
Recommended from our members
A novel design for an RF MEMS resistive switch on PCB substrate
Copyright @ 2008 Stimulation Action on MEM
Novel approaches in voltage-follower design
The aim of this research programme was to design and develop novel voltagefollowerslbuffers, suitable for radio frequency (RF) applications. The emphases throughout has been on improving key characteristics, in particular distortion, operating bandwidth, input and output impedances, offset-voltage and power supply demands of the design. The majority of the results of this work have been reported by the author in the technical literature (I] to (6). Initially this research focuses on the investigation of the underlying operating principles of the voltage-follower to provide an in-depth understanding of its operation. This study concentrates on establishing reasons for the poor distortion, low input and high output impedances and increased offset-voltage and confirmed that these designs have inherently poor performance in these parameters. The analysis is carried out using both theoretical modelling and computer simulation, using the wellestablished software package ORCAD PSpice. Despite the availability of high performance computer simulation tools, it becomes apparent that 'hand' calculations in the design process, generally based on DC and small-signal transistor parameters, are essential. Therefore a detailed analysis of the transistor-models used throughout this research is carried out with PSpice data. Using the analytical results of the conventional voltage-follower as a benchmark, various novel circuit techniques investigated. Several new circuits are proposed with respect to improving the previously mentioned key characteristics. The first technique comprises local feedback and single-valued current biasing and 111 consists of emitter-followers exclusively throughout the signal path, keeping the distortion of the input signal to low levels [1 J, (2). The second technique is based on local feedback with double-valued current biasing, increasing somewhat the power dissipation but reducing, notably, the distortion of the configuration [3J, [4J, [5J, [6J. The final technique employs the emitter-followers throughout the signal path in combination with global feedback and double-valued current biasing, which presents significantly better results, on certain parameters, than conventional and existing configurations. It is anticipated that this work will be published in the near future
Recommended from our members
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
Recommended from our members
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
Skyrmions, Rational Maps & Scaling Identities
Starting from approximate Skyrmion solutions obtained using the rational map
ansatz, improved approximate Skyrmions are constructed using scaling arguments.
Although the energy improvement is small, the change of shape clarifies whether
the true Skyrmions are more oblate or prolate.Comment: 13 pages, 3 figure
Recommended from our members
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
Deflation-based Identification of Nonlinear Excitations of the 3D Gross--Pitaevskii equation
We present previously unknown solutions to the 3D Gross--Pitaevskii equation
describing atomic Bose-Einstein condensates. This model supports elaborate
patterns, including excited states bearing vorticity. The discovered coherent
structures exhibit striking topological features, involving combinations of
vortex rings and multiple, possibly bent vortex lines. Although unstable, many
of them persist for long times in dynamical simulations. These solutions were
identified by a state-of-the-art numerical technique called deflation, which is
expected to be applicable to many problems from other areas of physics.Comment: 9 pages, 11 figure
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
Kuznetsov-Ma breather-like solutions in the Salerno model
The Salerno model is a discrete variant of the celebrated nonlinear
Schr\"odinger (NLS) equation interpolating between the discrete NLS (DNLS)
equation and completely integrable Ablowitz-Ladik (AL) model by appropriately
tuning the relevant homotopy parameter. Although the AL model possesses an
explicit time-periodic solution known as the Kuznetsov-Ma (KM) breather, the
existence of time-periodic solutions away from the integrable limit has not
been studied as of yet. It is thus the purpose of this work to shed light on
the existence and stability of time-periodic solutions of the Salerno model. In
particular, we vary the homotopy parameter of the model by employing a
pseudo-arclength continuation algorithm where time-periodic solutions are
identified via fixed-point iterations. We show that the solutions transform
into time-periodic patterns featuring small, yet non-decaying far-field
oscillations. Remarkably, our numerical results support the existence of
previously unknown time-periodic solutions {\it even} at the integrable case
whose stability is explored by using Floquet theory. A continuation of these
patterns towards the DNLS limit is also discussed.Comment: 9 pages, 4 figure