Broadband tunable acoustic metasurface based on piezoelectric composite structure with two resonant modes

2021 ◽  
Author(s):  
Yao-Yin Peng ◽  
Jin-Heng Chen ◽  
Zhang-Zhao Yang ◽  
Xin-Ye Zou ◽  
Chao Tao ◽  
...  
Keyword(s):  
Composite Structure ◽  
Beam Steering ◽  
Piezoelectric Composite ◽  
Frequency Range ◽  
Acoustic Beam ◽  
Resonant Frequencies ◽  
Operating Frequency Range ◽  
Resonant Modes ◽  
Simulation And Experiment ◽  
Good Potential

Abstract In this letter, we propose a deep-wavelength tunable acoustic metasurface composed of a fixed piezoelectric composite structure with a broad operating frequency range. The metasurface unit has two tunable resonant frequencies determined by specific external inductors and can continuously modulate the phase of transmitted wave. The influence of the inductors on the resonant frequencies are studied by simulation and experiment. Moreover, the functions of acoustic beam steering and focusing by the designed metasurface at three arbitrarily chosen frequencies are verified in simulation. This work may have good potential in design of acoustic metasurfaces with broadband operating frequencies.

A Cement Based Piezoelectric Composite Sensorfor Health Monitoring of Civil Engineering Structure

2011 ◽  
Vol 306-307 ◽  
pp. 293-296 ◽  
Author(s):  
Shi Feng Huang ◽  
Jun Chang ◽  
Lei Qin ◽  
Xiao Ming Yang ◽  
Zong Jin Li ◽  
...  
Keyword(s):  
Health Monitoring ◽  
Output Voltage ◽  
Civil Engineering ◽  
Piezoelectric Composite ◽  
Frequency Range ◽  
Sensing Element ◽  
Complex Load ◽  
Good Potential ◽  
Input Load ◽  
Composite Sensor

A cement based piezoelectric composite sensor using 1-3 cement based piezoelectric composite as sensing element was fabricated. The basic properties of the sensor were mainly investigated. The results indicate that in the frequency range from 0.1 to 40 Hz, the output voltage amplitudes of the sensor increase nonlinearly with increasing frequency of input load under 10 Hz. When the frequency of input load is larger than about 10 Hz, the output voltage amplitudes of the sensor is nearly independent of frequency. There exists an obviously linear relationship between the output voltage amplitude of the sensor and input load amplitude. The output voltage of the sensor is correspond to the complex load very well. The phase difference between the output voltage of the sensor and input load is near zero. Therefore such sensors have a good potential to be used in civil engineering structural health monitoring.

Low-frequency sound absorption of a tunable multilayer composite structure

2021 ◽  
pp. 107754632110082
Author(s):  
Hanbo Shao ◽  
Jincheng He ◽  
Jiang Zhu ◽  
Guoping Chen ◽  
Huan He
Keyword(s):  
Porous Material ◽  
Absorption Coefficient ◽  
Composite Structure ◽  
Low Frequency ◽  
Acoustic Absorption ◽  
Multilayer Composite ◽  
Absorption Frequency ◽  
Acoustic Absorption Coefficient ◽  
Simulation And Experiment ◽  
Single Material

Our work investigates a tunable multilayer composite structure for applications in the area of low-frequency absorption. This acoustic device is comprised of three layers, Helmholtz cavity layer, microperforated panel layer, and the porous material layer. For the simulation and experiment in our research, the absorber can fulfill a twofold requirement: the acoustic absorption coefficient can reach near 0.8 in very low frequency (400 Hz) and the range of frequency is very wide (400–3000 Hz). In all its absorption frequency, the average of the acoustic absorption coefficient is over 0.9. Besides, the absorption coefficient can be tunable by the scalable cavity. The multilayer composite structure in our article solved the disadvantages in single material. For example, small absorption coefficient in low frequency in traditional material such as microperforated panel and porous material and narrow reduction frequency range in acoustic metamaterial such as Helmholtz cavity. The design of the composite structure in our article can have more wide application than single material. It can also give us a novel idea to produce new acoustic devices.

scholarly journals Design of Wideband Bandpass Filter Based on Corrugated Disk Resonator with Multiple Resonant Modes

Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2614
Author(s):  
Qian Yang ◽  
Shuangyang Liu ◽  
Hongyu Shi ◽  
Kai-Da Xu ◽  
Xinyue Dai ◽  
...  
Keyword(s):  
Theoretical Analysis ◽  
Bandpass Filter ◽  
Design Method ◽  
Center Frequency ◽  
Localized Surface Plasmons ◽  
Metallic Structure ◽  
Disk Resonator ◽  
Resonant Frequencies ◽  
Resonant Modes ◽  
Via Holes

A corrugated disk resonator with eight grooves is proposed for wideband bandpass filter (BPF) design. Due to the spoof localized surface plasmons resonances of the corrugated metallic structure, the dipole, quadrupole, hexapole modes, and a fundamental mode excited by the introduced short-circuited via holes are employed to realize four transmission poles (TPs) in the passband. The theoretical analysis is described by the electric field and current distributions on the resonator. The resonant frequencies can be tuned easily by the parameters of the structure, which can be used to adjust the center frequency and bandwidth of the BPF freely. Furthermore, two resonators are cascaded to obtain eight TPs to improve the selectivity performance. Finally, three fabricated filters demonstrate the design method.

FORMATION OF A SCANNING ANTENNA BASED ON A HALF-WAVE DIPOLE

2021 ◽  
pp. 20-24
Author(s):  
С.М. Фёдоров ◽  
Е.А. Ищенко ◽  
И.А. Баранников ◽  
К.А. Бердников ◽  
В.В. Кузнецова
Keyword(s):  
Short Distance ◽  
Electromagnetic Waves ◽  
High Stability ◽  
Frequency Range ◽  
Current Position ◽  
Form Complex ◽  
Operating Frequency Range ◽  
Half Wave ◽  
Focus Radiation ◽  
Antenna Systems

Рассматривается полуволновый диполь с установленным рефлектором, который позволяет производить сканирование пространства с использованием вращения рефлектора вокруг диполя. Для полученной конструкции производилось моделирование основных параметров, которые показали высокую стабильность при различных положениях рефлектора, постоянное значение коэффициента направленного действия, ширины главного лепестка. Изменение направления излучения совпадает с текущим положением рефлектора. По сравнению с ситуацией, когда у антенны отсутствовал рефлектор, КНД антенны увеличился, так как произошла фокусировка электромагнитных волн. Коэффициент полезного действия и передне-заднее отношение сохраняют высокие значения во всем диапазоне рабочих частот. Применение предложенной конструкции позволяет упростить конструкцию сканирующих антенн, так как для ее реализации требуются лишь полуволновой диполь и плоский рефлектор, установленный на малом расстоянии от источника излучения. В процессе управления характеристиками требуется вращать рефлектор вокруг диполя, при этом диполь остается неподвижным, что позволяет повысить эффективность предложенной конструкции, так как не требуется формировать сложных антенных систем или устанавливать комбинацию из нескольких антенн для фокусировки излучения в одном направлении от источника The article discusses a half-wave dipole with an installed reflector, which allows scanning space using the rotation of the reflector around the dipole. For the resulting structure, we simulated the main parameters, which showed high stability at various positions of the reflector, a constant value of the directivity factor, and the width of the main lobe. The change in the direction of radiation coincides with the current position of the reflector. Compared to the situation when the antenna did not have a reflector, the directivity of the antenna increased since the focusing of electromagnetic waves took place. The efficiency and the front-to-back ratio remain high throughout the entire operating frequency range. The use of the proposed design makes it possible to simplify the design of scanning antennas since the implementation of the proposed design requires only a half-wave dipole and a flat reflector installed at a short distance from the radiation source. In the process of controlling the characteristics, it is required to rotate the reflector around the dipole, while the dipole remains stationary, which makes it possible to increase the efficiency of the proposed design, since it is not required to form complex antenna systems or install a combination of several antennas to focus radiation in one direction from the source

scholarly journals Metal rings and discs Matlab/Simulink 3D model for ultrasonic sandwich transducer design

2012 ◽  
Vol 44 (3) ◽  
pp. 287-298 ◽  
Author(s):  
I. Jovanovic ◽  
D. Mancic ◽  
V. Paunovic ◽  
M. Radmanovic ◽  
V.V. Mitic
Keyword(s):  
Resonance Frequency ◽  
3D Model ◽  
Mechanical Impedance ◽  
Analytical Models ◽  
Resonant Frequencies ◽  
Matlab Simulink ◽  
Simulink Model ◽  
Metal Rings ◽  
Resonant Modes ◽  
Transducer Design

Metal-endings are integral part of different ultrasonic sandwich transducers. In this paper a new Matlab/Simulink 3D model of the finite metal rings and discs of various dimensions is realized. With this model, which describes both the thickness and the radial resonant modes, and the coupling between them, mechanical impedance of the sample can be easily computed. Resonance frequency-length curves for rings and disks with various materials and for different selected dimensions are given. Also, comparisons of the different approaches in determining of their resonant frequencies are shown. The proposed Matlab/Simulink model requires simpler implementation than other analytical models. That enabled modifying of 1D theory and simplified modelling and projecting of the ultrasonic sandwich transducers with short-endings. Finally, the computed and experimental results are compared.

scholarly journals Electromagnetic Topology Analysis to Coupling Wires Enclosed in Cavities with Apertures

2010 ◽  
Vol 2010 ◽  
pp. 1-11 ◽  
Author(s):  
Ying Li ◽  
Jianshu Luo ◽  
Guyan Ni ◽  
Jiyuan Shi
Keyword(s):  
Analytic Solutions ◽  
Numerical Results ◽  
Coupling Theory ◽  
Cavity Model ◽  
Frequency Range ◽  
Topology Analysis ◽  
Resonant Frequencies ◽  
Load Response ◽  
Aperture Coupling ◽  
Coupling Current

We use both electromagnetic topology (EMT) and the Baum-Liu-Tesche (BLT) equation to analyze a cavity model with an aperture. More precisely, we combine the aperture coupling theory and EMT to study the issues of the electromagnetic field penetration through apertures into a cavity and the coupling to a two-wire transmission line in it. We employ the equivalence principle to establish the equivalent source on the aperture. Then, we obtain the semi analytic solutions of the load response of the two-wire line in the cavity based on the Baum-Liu-Tesche (BLT) equation. In addition, based on the Agrawal model, we give the coupling current distribution at two loads for a two-wire line in the cavity. Finally, we present some numerical results to demonstrate the semi-analytic approach of this paper. In fact, these numerical results on the electric field shielding (EFS) of a rectangular cavity with an aperture agree well with the experimental results in the literature. Furthermore, for a two-wire line in the cavity with an aperture the induced current peaks at loads are observed in the frequency range, some of which are associated with the resonance of the aperture, and others correspond to the resonant frequencies of the cavity.

scholarly journals Design of Broadband Compact Canonical Triple-Sleeve Antenna Operating in UHF Band

2021 ◽  
Vol 21 (4) ◽  
pp. 291-298
Author(s):  
Chandana SaiRam ◽  
Damera Vakula ◽  
Mada Chakravarthy
Keyword(s):  
Wireless Communication ◽  
Instantaneous Frequency ◽  
Dipole Antenna ◽  
Frequency Range ◽  
Broadband Antenna ◽  
Operating Frequency Range ◽  
Half Wave ◽  
Measurement Results ◽  
Antenna Configuration ◽  
Good Agreement

In this paper, a novel compact broadband antenna at UHF frequencies is presented with canonical shapes. Hemispherical, conical and cylindrical shapes have all been considered for antenna configuration. The designed antenna provides an instantaneous frequency range from 370 to 5,000 MHz with omnidirectional characteristics. The antenna was simulated in CST Microwave Studio, fabricated and evaluated; the results are presented. The simulated and measurement results are in good agreement. The antenna has voltage standing wave ratio (VSWR) ≤ 1.9:1 in 400–570 MHz, 2,530–3,740 MHz and 4,180–4,620 MHz; it has VSWR ≤ 3:1 over the operating frequency range 370–5,000 MHz and the measured gain varies from -0.6 to 4.5 dBi over the frequency band. The concept of canonical-shaped antenna elements and the incorporation of triple sleeves resulted in a reduction of the length of the antenna by 62% compared to the length of a half-wave dipole antenna designed at the lowest frequency. The antenna can be used for trans-receiving applications in wireless communication.

Sign in / Sign up

Export Citation Format

Share Document