Insertion loss of regular finite cylinder arrays with porous layers between the rows

2021 ◽  
Vol 149 (4) ◽  
pp. 2395-2402
Author(s):  
D. P. Jena ◽  
Xiaojun Qiu
Keyword(s):  
Insertion Loss ◽  
Finite Cylinder ◽  
Porous Layers ◽  
Cylinder Arrays

scholarly journals Two- and Three-Dimensional Simulation of Sound Attenuation by Cylinder Arrays

2019 ◽  
Vol 142 (1) ◽  
Author(s):  
Junjian Zhang ◽  
Z. Charlie Zheng ◽  
Guoyi Ke
Keyword(s):  
Periodic Structures ◽  
Three Dimensional ◽  
Measurement Data ◽  
Sound Attenuation ◽  
3D Simulation ◽  
Fdtd Simulation ◽  
Finite Cylinder ◽  
Immersed Boundary ◽  
Cylinder Arrays ◽  
Third Dimension

Abstract A finite-difference time-domain (FDTD) simulation coupled with an immersed-boundary method is used to investigate sound attenuation through both two-dimensional (2D) and three-dimensional (3D) cylinder arrays. The focus is on sound attenuation behaviors near Bragg’s bandgap frequencies for periodic structures. Both 2D and 3D simulations show that the finite cylinder arrays produce significant sound attenuation near the bandgap frequencies, with more attenuation effects in the 2D cylinder arrays because of the uniformity of sound source and neglected structure diffraction in the third dimension. When extended to 3D simulation, which can accommodate physically realistic conditions, sound attenuation near Bragg’s frequencies is reduced in comparison with 2D results. The 3D simulation also reaches a better agreement when comparing with the measurement data from the literature. Results and discussions on arrangement of cylinder arrays to achieve better sound attenuation effects are also presented.

In Situ microscopy of the anodic etching of silicon

1995 ◽  
Vol 53 ◽  
pp. 232-233
Author(s):  
Frances M. Ross ◽  
Peter C. Searson
Keyword(s):  
Composite Structures ◽  
High Surface ◽  
High Surface Area ◽  
Chemical Properties ◽  
Selective Etching ◽  
Silicon On Insulator ◽  
Second Phase ◽  
Porous Layers ◽  
New Class ◽  
Porous Semiconductors

Porous semiconductors represent a relatively new class of materials formed by the selective etching of a single or polycrystalline substrate. Although porous silicon has received considerable attention due to its novel optical properties1, porous layers can be formed in other semiconductors such as GaAs and GaP. These materials are characterised by very high surface area and by electrical, optical and chemical properties that may differ considerably from bulk. The properties depend on the pore morphology, which can be controlled by adjusting the processing conditions and the dopant concentration. A number of novel structures can be fabricated using selective etching. For example, self-supporting membranes can be made by growing pores through a wafer, films with modulated pore structure can be fabricated by varying the applied potential during growth, composite structures can be prepared by depositing a second phase into the pores and silicon-on-insulator structures can be formed by oxidising a buried porous layer. In all these applications the ability to grow nanostructures controllably is critical.

Method for Evaluating Insertion Loss of EMI Filter Connected to Semiconductor Power Converters

2012 ◽  
Vol 132 (7) ◽  
pp. 727-735 ◽  
Author(s):  
Michio Tamate ◽  
Tamiko Sasaki ◽  
Akio Toba ◽  
Yasushi Matsumoto ◽  
Keiji Wada ◽  
...  
Keyword(s):  
Insertion Loss ◽  
Power Converters ◽  
Emi Filter

Performance and Reliability of a MEMS-based tunable optical filter operating in the 1565 nm-1525 nm wavelength range

2002 ◽  
Vol 722 ◽  
Author(s):  
T. S. Sriram ◽  
B. Strauss ◽  
S. Pappas ◽  
A. Baliga ◽  
A. Jean ◽  
...  
Keyword(s):  
Silicon Nitride ◽  
Line Width ◽  
Insertion Loss ◽  
Optical Filter ◽  
Single Mode ◽  
Single Mode Fiber ◽  
Reliability Testing ◽  
Silicon Nitride Membrane ◽  
Tunable Optical Filter ◽  
Extensive Performance

AbstractThis paper describes the results of extensive performance and reliability characterization of a silicon-based surface micro-machined tunable optical filter. The device comprises a high-finesse Fabry-Perot etalon with one flat and one curved dielectric mirror. The curved mirror is mounted on an electrostatically actuated silicon nitride membrane tethered to the substrate using silicon nitride posts. A voltage applied to the membrane allows the device to be tuned by adjusting the length of the cavity. The device is coupled optically to an input and an output single mode fiber inside a hermetic package. Extensive performance characterization (over operating temperature range) was performed on the packaged device. Parameters characterized included tuning characteristics, insertion loss, filter line-width and side mode suppression ratio. Reliability testing was performed by subjecting the MEMS structure to a very large number of actuations at an elevated temperature both inside the package and on a test board. The MEMS structure was found to be extremely robust, running trillions of actuations without failures. Package level reliability testing conforming to Telcordia standards indicated that key device parameters including insertion loss, filter line-width and tuning characteristics did not change measurably over the duration of the test.

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