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MEMS Disc resonators have emerged as a leading choice for RF communication systems upto UHF range. Inorder to evaluate the performance of a MEMS resonator it is important to understand the physical loss mechanisms, which limit the quality factor. In this paper, an important energy loss mechanism — ThermoElastic Damping (TED) effect in disc resonators is analyzed by evaluating the TED limited Quality...
MEMS based Bulk Acoustic Wave (BAW) resonators are rapidly growing highly integrated devices which can offer high Quality Factor (Q) values at operating frequencies up to the VHF and UHF ranges i.e. high f-Q product. In a BAW resonator, a piezoelectric layer which is the main part of the resonator generates the vertical acoustic standing waves within the layer. The resonant frequency of the BAW resonators...
The present work uses MEMS switches for electrostatic control of centre frequency and bandwidth in a Coplanar Waveguide (CPW) Spurline filter. The filter consists of short end series stub resonators etched in the signal line of CPW. MEMS capacitive shunt switches are loaded across the stubs and across the inter resonator spaces and actuation of the switches alter the effective electrical length of...
The radiation characteristics of a dipole antenna when immersed in both fresh and seawater are assessed through simulation and experimental work. Simulations show that the antenna's bandwidth and radiation pattern change with the properties of the medium where it is placed, namely the conductivity of the medium. Two dipoles antennas with current baluns were built and tested experimentally in freshwater...
This manuscript represents the two half circular gap coupled disk patch antenna stacked with D.G.S. (Defected Ground Structure) for dual-wideband application. The antenna has an overall size of 40.0×40.0×1.6mm3 and gives the results of dual band performance. The proposed antenna can be used in military communication, wideband global satellite communication systems (WGS) (9.43–10.08 GHz) and in Airport...
In this paper the reconfigurable dual band micro strip patch antenna with resonant frequencies 1102MHz and 912MHz is analyzed with the change in position of internal two switches which are connecting the four antenna patches. It is showed that reconfigurable antenna changes the basic parameters with the change in the position of the switches which are being used to connect the antenna structure. A...
This paper focuses on the design of high quality spiral resonators for maximising wireless power transfer efficiency between an AUV and an underwater docking station. By using 3D electromagnetic simulations and numerical analysis, the relevant parameters for quality factor computation are extracted. The impact of different variables on a spiral resonator's quality factor is assessed, allowing to conclude...
A wideband frequency reconfigurable dielectric resonator antenna (DRA) is presented and discussed. The proposed antenna is capable of frequency switching at two different bands between 4.12 GHz and 8.85 GHz. The rectangular dielectric resonator with a permittivity of 15 is fed by U-shaped microstrip feed line. By setting the switch on the connecting lines of a network that feeds the dielectric element...
In this paper we assess the influence of the conductivity of the medium on the radiation characteristics and input impedance of a loop antenna designed for underwater communications. The initial study is based on simulation of the antenna characteristics using FEKO electromagnetic (EM) software. Additionally, an equivalent circuit model of the antenna is also obtained and simulation of the input impedance...
One of the biggest challenges for measuring soft tissue stiffness using tactile sensors is to have an output independent of the contact conditions. Although the approach of using two springs with different stiffness is used, the output of sensor is usually unstable because of the soft tissue surface irregularity. This irregularity creates an inclination angle between the sensor tips and the tissue...
The performance analysis of reflectarray resonant elements based on Finite Integral Method is presented in this work for 5G antenna systems. Reflection loss, bandwidth and linear phase range of square and circular resonant element configurations have been investigated at 15 GHz and 20 GHz frequencies. Periodic reflectarrays consisting of 5×5 elements have been designed at 20 GHz for both elements...
A new metamaterial with negative permeability is presented in this study. Negative permeability metamaterials are called mu-negative (MNG) metamaterial as well. The transmission co-efficient of this metamaterial shows resonance at a certain frequency in the C-band of microwave frequency range for the z-axis wave propagation. It also exhibits the characteristics of a mu-negative (MNG) metamaterial...
An analysis of a fractal-like circular patch element for miniaturized frequency selective surfaces (FSSs) is presented. The analysis is performed using the Wave Concept Iterative Procedure (WCIP), a full-wave method. The proposed FSS geometry has a stable frequency response in relation to the oblique incidence of plane waves. In addition, the FSS patch element presents a fractal-like behavior, being...
Vibration attenuation is necessary in many electro-mechanical systems. In this paper electromagnetic damping is applied on a flexible cantilever beam (FCB) made of ferromagnetic material. The lateral vibration is controlled by employing two electromagnetic poles mounted in the same axis as that of a vibrating cantilever beam. A power amplifier is developed to provide desired current to the electromagnet...
A Wave Concept Iterative Procedure (WCIP) based on transverse waves formulation is presented. This method is applied to analyze annular microstrip patch antennas on anisotropic substrates. The use of FFT algorithm to define a fast modal Fourier transform results in accurate solutions with significant savings in computation time and memory requirements. WCIP results are compared with the HFSS simulation...
We present an electronically-controlled vanadium dioxide (VO2)-based millimeter-wave phase modulator. The phase modulator consists of a resonant meta-surface fabricated on a thin VO2 film integrated with a voltage-controlled heating electrode layer. By varying the applied voltage to the heating electrodes we control the electromagnetic properties of the VO2 layer and shift the resonance frequency...
We demonstrate a pump-free method to control the length of liquid metal in a capillary as a means to change the operating frequency of a monopole antenna. An applied DC voltage controls the surface tension of the liquid metal filament, causing it to lengthen or contract, varying the antenna's resonant length. A closed-loop feedback system tracks the antenna's operating frequency and adjusts the applied...
A compact frequency-reconfigurable dielectric resonator antenna (DRA) for LTE/WWAN and WLAN applications is investigated and presented. The proposed antenna provides the frequency tuning between 1.60 and 2.71 GHz. The design consists of four identical rectangular dielectric resonators with permittivity of 10 each and three p-i-n diode switches that are located on the feedline network between each...
This paper presents brief study of MEMS technology and development of condenser microphone with no holes in back plate. In general silicon materials are used in MEMs. MEMS devices can be fabricated by using bulk micromachining and surface micromachining. Microphone is designed by using a thin silicon crystalline material as flexible diaphragm and gold material as back plate. The aim of this paper...
This paper investigates the performance of a circular patch antenna deployed with a parasitic ring and compares the performances with a conventional circular patch antenna in terms of gain, return loss, and radiation pattern. The antenna is fed by a coaxial probe and provided with a full ground plane. Compared with previous gain enhancement methods, the proposed metal ring resonator offers reduced...
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