scholarly journals Analysis and Design of Single-Phase Unidirectional Transducers with High Directivity

2021 ◽  
Vol 11 (16) ◽  
pp. 7500
Author(s):  
Xueping Sun ◽  
Shaobo Ge ◽  
Xiuting Shao ◽  
Shun Zhou ◽  
Wen Wang ◽  
...  
Keyword(s):  
Reflection Coefficient ◽  
Insertion Loss ◽  
Single Phase ◽  
Center Frequency ◽  
The Finite Element Method ◽  
Analysis And Design ◽  
Saw Devices ◽  
Optimal Value ◽  
Simulation Results ◽  
The Relationship

Electrode-width-controlled (EWC) single-phase unidirectional transducers (SPUDT) contribute to reduction of insertion loss of surface acoustic wave (SAW) devices due to their strong unidirectional properties. In this work, we propose a method to optimize the unidirectionality of EWC-SPUDT based on our research results that the unidirectionality of the EWC-SPUDT cell is strongly related to its reflectivity and its unidirectional angle. Furthermore, in order to ensure strong unidirectionality to achieve low insertion loss, a simulator based on the finite element method (FEM) is used to study the relationship between geometrical configuration of the EWC-SPUDT cell and its reflection coefficient, as well as its transduction coefficient. Simulation results indicate that the reflection coefficient of the optimized EWC-SPUDT cell composed of 128° YX lithium niobite (LiNbO3) substrate and Al electrodes with thickness of 0.3μm reaches the optimal value of 5.17% when the unidirectional angle is designed to be −90°. A SAW delay line is developed with the optimized EWC-SPUDT cell without weighing, and the simulation results are verified by experiments. The experimental results show that the directivity exceeds 30 dB at the center frequency and the insertion loss is just 6.7 dB.

Study of a Low Insertion Loss SAW Filter with SPUDT Structure Using YZ-LiNbO3

2012 ◽  
Vol 251 ◽  
pp. 139-142 ◽  
Author(s):  
Hua Jiang ◽  
Wen Ke Lu ◽  
Shi Gen Shen ◽  
Zheng Guang Xie
Keyword(s):  
Frequency Response ◽  
Insertion Loss ◽  
Single Phase ◽  
Electromechanical Coupling ◽  
Piezoelectric Materials ◽  
Center Frequency ◽  
Electronic Systems ◽  
Coupling Constant ◽  
Low Insertion Loss ◽  
Simulation Results

To meet the demand for low insertion loss, we have studied a SAW filter with single phase unidirectional transducer (SPUDT) structure using piezoelectric materials YZ-LiNbO3. This article shows the simulation results of the SAW filter using Matlab software with the SAW velocity 3488m/s and electromechanical coupling constant 0.048. The theoretical center frequency is 72MHz and the 3dB bandwidth is 2.9MHz. The total frequency response of the entire SAW device is the product of the frequency response of the input transducer and the output transducer. It can be seen from the simulation results that the magnitude response and the linear phase response of interdigital transducer are consistent with the theoretical values and the minimum insertion loss reaches 5.43dB. So the low insertion loss SAW filter with SPUDT structure using YZ-LiNbO3 adapts the requirements of the radar, communications and other electronic systems.

scholarly journals Design and Realization of Coupled Line Bandpass Filter Using Compact Structure at Frequencies of 3300 MHz – 3400 MHz for WiMAX Application

2016 ◽  
Vol 16 (1) ◽  
pp. 11
Author(s):  
Arief Budi Santiko ◽  
Yahya Syukri Amrullah ◽  
Yuyu Wahyu ◽  
Muhammad Ilham Maulana ◽  
Bambang Setia
Keyword(s):  
Insertion Loss ◽  
Return Loss ◽  
Bandpass Filter ◽  
Center Frequency ◽  
Design System ◽  
Compact Structure ◽  
Coupled Line ◽  
Broadband Wireless ◽  
Simulation And Optimization ◽  
Simulation Results

In this paper, the design of microstrip BPF (Bandpass Filter) for WiMAX (Worldwide Interoperability for Microwave Access) application has been presented. The frequency band allocations for BWA (Broadband Wireless Access) in Indonesia are 2.3; 3.3 and 5.8 GHz. This microtrip BPF is designed using parallel coupled line in compact form and it has spesific parameter, i.e. 3.35 GHz center frequency, 400 MHz bandwidth, VSWR ≤ 2, -3 dB insertion loss and matching impedance between two port is 50 Ω. The Advanced Design System (ADS) software has been used during simulation and optimization. The simulation results show that return loss S11 and insertion loss S21 are -15.31 dB and -2.2 dB at 3.35 GHz respectively. For the design verification, the prototype of the proposed design wasfabricated and measured.The results of the fabrication approach of simulation results, which have return loss value S11and insertion loss S21 of the proposed microstrip filter are -18.20 dB and -2.91 dB at 3.35 GHz respectively. The result shows that the proposed design can be implemented forWiMAX communication system applications

The Design of Wide-Stopband HTS Bandpass Filter

2014 ◽  
Vol 936 ◽  
pp. 2214-2219 ◽  
Author(s):  
Hong Yang ◽  
Yan Zhou
Keyword(s):  
Fundamental Frequency ◽  
Insertion Loss ◽  
Simple Structure ◽  
Bandpass Filter ◽  
Center Frequency ◽  
Harmonic Frequency ◽  
Optimization Simulation ◽  
Frequency Optimization ◽  
Simulation Results

This paper presents the design of a wide-stopband HTS bandpass filter (BPF). The 9-pole wide-stopband BPF has a center frequency 2.21GHz and bandwidth 100 MHz. Based on the step impedance resonator,this filter increase the harmonic frequency to more than 3 times of fundamental frequency. Optimization simulation results shows that insertion loss is less than 0.3 dB in the passband,and stopband suppression is greater than 80 dB within 0~f0-BW and greater than 60 db within the f0 + BW ~ 3 f0. Within the passband, dB (S (2, 1)) < -20. This design not only achieved a good wide stopband and solved the interference problem but also had a simple structure which is easy to implement.

scholarly journals A Non-Volatile Tunable Terahertz Metamaterial Absorber Using Graphene Floating Gate

Micromachines ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 333
Author(s):  
Jinjun Bai ◽  
Wei Shen ◽  
Jia Shi ◽  
Wei Xu ◽  
Shusheng Zhang ◽  
...  
Keyword(s):  
Physical Mechanism ◽  
Metamaterial Absorber ◽  
Floating Gate ◽  
Center Frequency ◽  
Field Energy ◽  
The Finite Element Method ◽  
Photoelectric Detection ◽  
Potential Applications ◽  
Simulation Results ◽  
Metal Absorber

Based on the graphene floating gate, a tunable terahertz metamaterial absorber is proposed. Compared with the traditional graphene–dielectric–metal absorber, our absorber has the property of being non-volatile and capacity for anti-interference. Using the finite element method, the paper investigates the absorption spectra, the electric field energy distribution, the tunability and the physical mechanism. In addition, we also analyse the influence of geometry, polarization and incident angles on the absorption. Simulation results show that the bandwidth of the absorption above 90% can reach up to 2.597 THz at the center frequency of 3.970 THz, and the maximum absorption can be tuned continuously from 14.405% to 99.864% by controlling the Fermi level from 0 eV to 0.8 eV. Meanwhile, the proposed absorber has the advantages of polarization insensitivity and a wide angle, and has potential applications in imaging, sensing and photoelectric detection.

scholarly journals 3D Simulation-Based Acoustic Wave Resonator Analysis and Validation Using Novel Finite Element Method Software

Sensors ◽  
2021 ◽  
Vol 21 (8) ◽  
pp. 2715
Author(s):  
Ruth Yadira Vidana Morales ◽  
Susana Ortega Cisneros ◽  
Jose Rodrigo Camacho Perez ◽  
Federico Sandoval Ibarra ◽  
Ricardo Casas Carrillo
Keyword(s):  
Finite Element ◽  
High Performance ◽  
Cloud Services ◽  
3D Simulation ◽  
3D Simulations ◽  
Acoustic Resonators ◽  
Analysis And Design ◽  
Wave Resonator ◽  
Film Bulk ◽  
Simulation Results

This work illustrates the analysis of Film Bulk Acoustic Resonators (FBAR) using 3D Finite Element (FEM) simulations with the software OnScale in order to predict and improve resonator performance and quality before manufacturing. This kind of analysis minimizes manufacturing cycles by reducing design time with 3D simulations running on High-Performance Computing (HPC) cloud services. It also enables the identification of manufacturing effects on device performance. The simulation results are compared and validated with a manufactured FBAR device, previously reported, to further highlight the usefulness and advantages of the 3D simulations-based design process. In the 3D simulation results, some analysis challenges, like boundary condition definitions, mesh tuning, loss source tracing, and device quality estimations, were studied. Hence, it is possible to highlight that modern FEM solvers, like OnScale enable unprecedented FBAR analysis and design optimization.

scholarly journals Improvement of Transverse-Flux Machine Characteristics by Finding an Optimal Air-Gap Diameter and Coil Cross-Section at the Given Magneto-Motive Force of the PMs

Energies ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 755
Author(s):  
Grebenikov Viktor ◽  
Oleksandr Dobzhanskyi ◽  
Gamaliia Rostislav ◽  
Rupert Gouws
Keyword(s):  
Cross Section ◽  
Computer Model ◽  
Single Phase ◽  
Air Gap ◽  
Laboratory Measurements ◽  
The Finite Element Method ◽  
Power Characteristics ◽  
Transverse Flux ◽  
Output Characteristics ◽  
The Given

This paper presents analysis and study of the single-phase transverse-flux machine. The finite element method results of the machine are compared with the laboratory measurements to confirm the accuracy of the computer model. This computer model is then used to investigate the effect of the machine’s geometry on its output characteristics. Parametric analysis of the machine is carried out to find the optimal air-gap diameter at which the cogging torque of the machine is minimal. In addition, the influence of the coil cross-section on the torque and output power characteristics of the machine is investigated and discussed.

Simulation of Intrinsic Diffusion in Multicomponent Multiphase Systems

1998 ◽  
Vol 527 ◽  
Author(s):  
M. Hunkel ◽  
D. Bergner
Keyword(s):  
Single Phase ◽  
Diffusion Flux ◽  
Wind Effect ◽  
Concentration Profiles ◽  
Intrinsic Diffusion ◽  
Cross Terms ◽  
Multiphase Systems ◽  
Random Alloy ◽  
Simulation Results ◽  
Vacancy Flux

ABSTRACTA simulation model for intrinsic diffusion of multicomponent multiphase systems is presented. The model is not restricted onto a certain number of components or phases. For simplicity, Manning's random alloy model with vanishing vacancy wind effect is used. Then the cross terms of the diffusion flux can be neglected. The simulation routine uses equations for the fluxes, the equation of continuity and an equation for the change of the thickness of volume elements due to the vacancy flux. With this model diffusions paths, concentration profiles, fluxes of the components as well as marker positions can be calculated. The shift of interfaces and the growth of new phases can also be determined. The simulation results were compared with experimental data of the Cu-Fe-Ni system. Diffusion was studied in single-phase areas and across interfaces.

TCAD Study of the Raised SiGe Source/Drain in 40nm PMOS

2015 ◽  
Vol 645-646 ◽  
pp. 70-74 ◽  
Author(s):  
Min Zhong ◽  
Yu Hang Zhao ◽  
Shou Mian Chen ◽  
Ming Li ◽  
Shao Hai Zeng ◽  
...  
Keyword(s):  
Computer Aided Design ◽  
Critical Role ◽  
Sige Layer ◽  
Strain Engineering ◽  
Effect Transistor ◽  
Simulation Results ◽  
Aided Design ◽  
The Relationship ◽  
Growth Experiments ◽  
Good Agreement

An embedded SiGe layer was applied in the source/drain areas (S/D) of a field-effect transistor to boost the performance in the p channels. Raised SiGe S/D plays a critical role in strain engineering. In this study, the relationship between the SiGe overfilling and the enhancement of channel stress was investigated. Systematic technology computer aided design (TCAD) simulations of the SiGe overfill height in a 40 nm PMOS were performed. The simulation results indicate that a moderate SiGe overfilling induces the highest stress in the channel. Corresponding epitaxial growth experiments were done and the obtained experimental data was in good agreement with the simulation results. The effect of the SiGe overfilling is briefly discussed. The results and conclusions presented within this paper might serve as useful references for the optimization of the embedded SiGe stressor for 40 nm logic technology node and beyond.

LABORATORY FOOTING TEST ON PARTIALLY SATURATED SANDY SOIL

2016 ◽  
Vol 78 (5-5) ◽  
Author(s):  
J. D. Nyuin ◽  
M. J. Md Noor ◽  
Y. Ashaari ◽  
C. Petrus ◽  
A. Albar
Keyword(s):  
Sandy Soil ◽  
Ground Surface ◽  
Matric Suction ◽  
Shallow Foundation ◽  
Analysis And Design ◽  
Test Tank ◽  
Partially Saturated ◽  
Saturated Condition ◽  
Conventional Analysis ◽  
The Relationship

Conventional analysis and design of shallow foundation are based on the assumption that the soil is under fully saturated condition. However, shallow foundations are typically constructed near the ground surface where the soil is under partially saturated condition. Therefore, more research to investigate the behaviour of shallow foundation in unsaturated soil is very essential in order to aid engineers in making good analysis and design. This paper presents a series of laboratory footing tests conducted on unsaturated sandy soil. A specially designed test tank was fabricated for the test. Square footings of two different sizes (100 mm x 100 mm and 150 mm x150 mm) were used and loaded on Rawang sand which has residual suction value of 10 kPa. The measured values of matric suction of the soil in the test tank were in the range of 0 to 30 kPa. Based on the results, it was observed that bearing capacities of shallow foundation under fully saturated condition were the lowest compared to soil under unsaturated conditions. The highest values were measured at matric suction equals to residual suction (i.e 10 kPa). Furthermore, the relationship between the bearing capacities of shallow foundation with the matric suction was observed to be non-linear.    

Deposition of Piezoelectric ZnO Films by RF Magnetron Sputtering and its Application to SAW Devices

2007 ◽  
Vol 1035 ◽  
Author(s):  
Seol Hee Choi ◽  
Chan Hyoung Kang
Keyword(s):  
Magnetron Sputtering ◽  
Rf Magnetron Sputtering ◽  
Silicon Wafers ◽  
Center Frequency ◽  
High Resistivity ◽  
Chemical Vapor Deposition Method ◽  
Zno Films ◽  
Optimum Process ◽  
Optimum Conditions ◽  
Saw Devices

AbstractHighly c-axis oriented, dense, and fine-grained polycrystalline ZnO films with smooth surface and high resistivity were deposited on 4 inch silicon wafers by employing ZnO targets in a radio-frequency (RF) magnetron sputtering system. By changing applied RF power, substrate temperature and O2/Ar gas ratio, the optimum process parameters were found to be 150 W, 200 °C and 30/70, respectively. Applying the ZnO films deposited under these optimum conditions, surface acoustic wave (SAW) devices of ZnO/IDT/SiO2/Si structure were fabricated by conventional photolithography and etching processes. The interdigital transducers (IDT), made of the aluminum deposited by DC magnetron sputter, were patterned as 2.5/2.5 μm of finger width/spacing. Another type of SAW filter of IDT/ZnO/diamond/Si structure was fabricated. In this structure, high-quality nanocrystalline diamond (NCD) films were deposited on 4 inch silicon wafers by direct current (DC) plasma assisted chemical vapor deposition method using H2-CH4 mixture as precursor gas. On the top of the diamond films, ZnO films were deposited under the optimum conditions. The aluminum IDT pattern was fabricated on the ZnO/diamond layered films. The characteristics of the fabricated SAW devices were evaluated in terms of center frequency, insertion loss, and wave propagation velocity.

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