scholarly journals Study on Double-sided Impedance Matching of Spherical Focusing Transducer in Ultrasonic Abrasive Flow Polishing System

2021 ◽  
Author(s):  
Li Wei ◽  
Hua Li ◽  
Dong Wei
Keyword(s):  
Sound Pressure ◽  
Ultrasonic Transducer ◽  
Impedance Matching ◽  
Matching Theory ◽  
Experimental Result ◽  
Efficient Utilization ◽  
Factors Affecting ◽  
Traditional Structure ◽  
Matching Structure ◽  
Abrasive Flow Polishing

Abstract The impedance matching of ultrasonic focusing spherical transducer is one of the primary factors affecting its work efficiency in ultrasonic focusing flow polishing system. To realize the efficient utilization of the vibration energy of the transducer, there are different requirements for the front and rear matching structure of the transducer. That is, the front matching structure should have high transmittance, and the rear matching structure should have high reflectivity. Based on the acoustic impedance matching theory and Kirchhoff's theory, the Influence of the front & back impedance matching structure of spherical focusing ultrasonic transducer to the focus sound pressure is studied theoretically and experimentally. The new matching structure for spherical focusing transducer is proposed based on above research. The experimental result shows that the focus sonic pressure with the new matching structure is increased by 72.03% compared with the traditional structure.

scholarly journals REASERCH ON A WATER-IMMERSED WIDE BAND HORN ANTENNA WITH WATER-FILLED COAXIAL IMPEDANCE MATCHING STRUCTURE

2019 ◽  
Vol 77 ◽  
pp. 115-123 ◽  
Author(s):  
Yang Yang ◽  
Lianghao Guo ◽  
Qing Zhou ◽  
Zhe Wu ◽  
Haibo Jiang ◽  
...  
Keyword(s):  
Impedance Matching ◽  
Wide Band ◽  
Horn Antenna ◽  
Matching Structure

scholarly journals Mathematical modeling and experimental study on solid–liquid suspension separation in ultrasonic standing wave field

2021 ◽  
pp. 146134842110229
Author(s):  
Yajing Wang ◽  
Liqun Wu ◽  
Yaxing Wang ◽  
Yafei Fan
Keyword(s):  
Standing Wave ◽  
Sound Pressure ◽  
Acoustic Radiation ◽  
Sound Field ◽  
Radiation Force ◽  
High Energy ◽  
Factors Affecting ◽  
Liquid Suspension ◽  
Ultrasonic Standing Wave ◽  
Solid Liquid

A new method of removing waste chips is proposed by focusing on the key factors affecting the processing quality and efficiency of high energy beams. Firstly, a mathematical model has been established to provide the theoretical basis for the separation of solid–liquid suspension under ultrasonic standing wave. Secondly, the distribution of sound field with and without droplet has been simulated. Thirdly, the deformation and movement of droplets are simulated and tested. It is found that the sound pressure around the droplet is greater than the sound pressure in the droplet, which can promote the separation of droplets and provide theoretical support for the ultrasonic suspension separation of droplet; under the interaction of acoustic radiation force, surface tension, adhesion, and static pressure, the droplet is deformed so that the gas fluid around the droplet is concentrated in the center to achieve droplet separation, and the droplet just as a flat ball with a central sag is stably suspended in the acoustic wave node.

A simple two-layer broadband metamaterial absorber for solar cells

2021 ◽  
pp. 2150291
Author(s):  
Fanyi Liu ◽  
Limei Qi
Keyword(s):  
Solar Cells ◽  
Precious Metal ◽  
Simple Structure ◽  
Impedance Matching ◽  
Cost Effective ◽  
Metamaterial Absorber ◽  
Matching Theory ◽  
Broadband Absorber ◽  
Broadband Absorption ◽  
Silicon Rods

A broadband absorber composed of silicon rods and nickel ground is proposed in the visible band. The absorption above 98% can be obtained in the frequency range of [Formula: see text] THz with strong polarization independence and angle independence. The impedance matching theory and field distributions of eigenmodes are used to analyze the physical mechanism of the broadband absorption. The absorber has a simple structure with only two layers, which is composed of silicon and nickel. Nickel is a non-precious metal, which is cheaper than the precious metal materials commonly used in metamaterial absorber. The proposed cost-effective absorber with simple structure has great potential in the application of solar cells.

The First Damped Frequency with Maximum Sound Pressure of a Miniature Loudspeaker for Cellular Phones

2010 ◽  
Vol 26 (4) ◽  
pp. 473-482 ◽  
Author(s):  
Y. C. Shiah ◽  
Jin H. Huang ◽  
Y.-L. Xue
Keyword(s):  
Explicit Form ◽  
Sound Pressure Level ◽  
Sound Pressure ◽  
Pressure Level ◽  
Experimental Result ◽  
Cellular Phones ◽  
Explicit Formulation ◽  
Dynamic Type ◽  
Smooth Region

ABSTRACTFor improving the performance of a miniature loudspeaker, engineers have been pursuing a goal of lowering its first damped frequency to have a broad and smooth region of its sound-pressure-level response. This article applies the approach of electro-mechano-acoustical analogy to study the first damped frequency of a miniature loudspeaker used for cellular phones. Using the analogy approach, the authors derive an explicit formulation for the sound-pressure-level of a typical miniature loudspeaker of dynamic type. The veracity of the derived formulation is verified by comparing with the experimental result recorded by B and K apparatus. The derived formulation is further simplified by neglecting factors that are either irrelevant or insignificant for the first damped frequency. Through basic algebraic and calculus operations, this article also presents an explicit form of the first damped frequency. This work has laid the platform for engineers to tailor the design in pursuit of improving the performance of miniature loudspeakers.

Impedance Matching between Signal Generator and Piezoelectric Transducer

2012 ◽  
Vol 472-475 ◽  
pp. 1488-1491
Author(s):  
Zhen Jiang Tan ◽  
Ming Zhou
Keyword(s):  
High Power ◽  
Piezoelectric Transducer ◽  
Perfect Matching ◽  
Impedance Matching ◽  
Signal Generator ◽  
Matching Theory ◽  
Signal Source ◽  
Key Technology ◽  
Power Pulse ◽  
High Power Pulse

In order to acquire enough energy, high power pulse must be used to drive a piezoelectric transducer. At the same time, it is a key technology to design an impedance matching circuit between a signal generator and a piezoelectric transducer so that signal source can transmit energy to the piezoelectric transducer effectively. In the paper, the impedance matching theory is analyzed. And, a method of using an oscilloscope to measure resonance frequency of the piezoelectric transducer is tested, through which, a perfect matching circuit is designed.

scholarly journals Wide CPW-Fed Multiband Wearable Monopole Antenna with Extended Grounds for GSM/WLAN/WiMAX Applications

2019 ◽  
Vol 2019 ◽  
pp. 1-14 ◽  
Author(s):  
Danvir Mandal ◽  
S. S. Pattnaik
Keyword(s):  
Resonance Condition ◽  
Coplanar Waveguide ◽  
Impedance Matching ◽  
Monopole Antenna ◽  
Antenna Performance ◽  
Quarter Wavelength ◽  
Triangular Patch ◽  
Matching Structure ◽  
Standard Limit ◽  
Good Agreement

A novel wide coplanar waveguide- (CPW-) fed multiband wearable monopole antenna is presented. The multiband operation is achieved by generating slanted monopoles of different lengths from an isosceles triangular patch. The different operating frequencies of the proposed antenna are associated with the lengths of the slanted monopoles, which are determined under quarter wavelength resonance condition. The CPW line is used as a multiband impedance-matching structure. The two grounds are slightly extended for better impedance matching. The proposed antenna is designed to cover the 1800 MHz GSM, 2.4 GHz/5.2 GHz WLAN, and 3.5 GHz WiMAX bands. The measured peak gains and impedance bandwidths are about 4.18/3.83/2.6/2.94 dBi and 410/260/170/520 MHz for the 1550-1960 MHz/2.3-2.56 GHz/3.4-3.57 GHz/5.0-5.52 GHz bands, respectively. The calculated averaged specific absorption rate (SAR) values at all the resonant frequencies are well below the standard limit of 2 W/kg, which ensures its feasibility for wearable applications. The antenna performance under different bending configurations is investigated and the results are presented. The reflection coefficient characteristics of the proposed antenna is also measured for different on-arm conditions and the results are compared. A good agreement between experimental and simulation results validates the proposed design approach.

A Polishing Method of Single-Incentive Ultrasonic Elliptical Vibration for Tungsten Carbide Mould

2011 ◽  
Vol 175 ◽  
pp. 140-144 ◽  
Author(s):  
Shao Hui Yin ◽  
Zhi Qiang Xu ◽  
Jian Wu Yu ◽  
Ze Biao Wang
Keyword(s):  
Surface Roughness ◽  
Finite Element ◽  
Tungsten Carbide ◽  
Ultrasonic Transducer ◽  
Experimental Result ◽  
Basic Principles ◽  
Elliptical Vibration ◽  
Element Simulation ◽  
Mould Surface ◽  
Ultrasonic Elliptical Vibration

The basic principles of ultrasonic transducer and ultrasonic elliptical vibration polishing are investigated. A new kind of single-incentive ultrasonic transducer is designed, and the finite element simulation is conducted, a polishing device is developed based on the ultrasonic elliptical vibration. The polishing experiment is adopted to polish a tungsten carbide mold with the diameter 5cm. The experimental result shows that the tungsten carbide mould surface roughness changes from the original 0.026μm to 0.017μm.

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