Design and simulation of a RF MEMS shunt switch for Ka and V bands and the impact of varying its geometrical parameters

RF MEMS plays an important role in microwave switching. The high performance of RF MEMS shunt such as high bandwidth, low insertion loss, and high isolation have made these switches well suitable for high performing microwave and millimeter wave circuits. This paper presents a RF MEMS shunt capacitive switch for Ka and V band application. This paper investigates the effect of various geometrical parameters on RF characteristics of the switch. The simulation results are presented and discussed.

Inside guide to getting published

In this seminar Dr Georgina Kelly gave useful advice to Higher Degree students and early career researchers on “When to publish what during your PhD; publishing in conferences and journals; impact versus reputation; and how to get your paper read by others’. Professor Terry Evans spoke of the importance of ‘Being strategic about publishing with(in) a thesis: the public and accessible nature of contemporary PhD theses and the implications for publishing during candidature and for subsequent publications’. In her presentation, ‘Transitioning: riding the wave’, Associate Professor Karen Stagnitti’s drew on her experiences as an HDR student and Early Career Researcher, raising the importance of recognizing opportunities for presenting at conferences, networking and publishing. Associate Professor Rohan Bastin, discussed benefits of ‘Developing pragmatic and rewarding publishing strategies; strategies and opportunities for having multiple publication projects on the go; tailoring one's output to the esteem criteria relevant to disciplines as well as one's own esteem criteria relevant to one's specialist area’.

Estimating non-response bias in a web-based survey of technology acceptance : a case study of unit guide information systems

Surveys are mostly challenged by response rates. Among the various types of survey research, web-based (internet-based/electronic/online) surveys are commonly used for data collection for a geographically diverse population. In surveys with high/low response rates, non-response bias can be a major concern. While it is not always possible to measure the actual bias due to non-response there are different approaches and techniques that help to identify reasons of non-response bias. The aims of this paper are twofold. (1) To provide an appropriate, interesting and important non-response bias case study for future web-based surveys that will provide guidance to other Information Systems researchers. The case-study concerns an online-survey to evaluate a technology acceptance model for Unit Guide Information systems (UGIS). (2) To discuss how nonresponse bias in a web-based technology acceptance study of an information system (UGIS in this case) can be contained and managed.

RF techniques for lowering the actuation voltage of RF MEMS shunt capacitor switch for C-K band

Increasing the capacitance ratio in RF MEMS shunt capacitive switch will increase its RF performance but also raise its actuation voltage. To improve the RF performance of the switch without increasing its capacitance ratio, this paper explores two methods: reducing the LC resonance from the mm-wave into the X-band by using an inductive bridge, and using two short high impedance transmission lines at both ends of the CPW line. Accordingly, this paper presents the design and simulation of an electro-static low actuation voltage and a very high isolation multipurpose switch with a very large bandwidth. The simulation results are presented and discussed.

Design and simulation of a high isolation RF MEMS shunt capacitive switch for C-K band

This paper presents a wide band RF MEMS capacitive switch. The LC resonant frequency is reduced from mm wave to X band frequencies at down-state by using a meander type membrane, with the frequency band is being increased by adding two short high impedance lines at both ends of coplanar waveguide (CPW). Moreover, this acts as T-match circuit in up-state position and improves the matching. Simulation results demonstrate that the capacitance ratio reduces from 50 to 21.4, S21 and S11 are less than −10dB for the entire frequency band at down-state and up-state. Also, a comprehensive and complete electric model of the switch is proposed and simulation results agree well with the characteristics of the physical structure of the MEMS switch. Vpull-in and Vpull-out of this switch are 8.1V and 0.3V, respectively.

Modelling of guided wave propagation with spectral element: application in structural engineering

Among many structural health monitoring (SHM) methods, guided wave (GW) based method has been found as an effective and efficient way to detect incipient damages. In comparison with other widely used SHM methods, it can propagate in a relatively long range and be sensitive to small damages. Proper use of this technique requires good knowledge of the effects of damage on the wave characteristics. This needs accurate and computationally efficient modeling of guide wave propagation in structures. A number of different numerical computational techniques have been developed for the analysis of wave propagation in a structure. Among them, Spectral Element Method (SEM) has been proposed as an efficient simulation technique. This paper will focus on the application of GW method and SEM in structural health monitoring. The GW experiments on several typical structures will be introduced first. Then, the modeling techniques by using SEM are discussed. © (2014) Trans Tech Publications, Switzerland.