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1

Improvement of Sound Insulation Through Double-Panel Structure by Using Hybrid Local Resonator Array

Ri Kyong-Su, Kim Myong-Jin, Son-U Se-Hyon

Archives of Acoustics

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2023

|

Vol. 48, No. 1

63--70

EN

In this paper, we present one approach to improve the soundproofing performance of the double-panel structure (DPS) in the entire audible frequencies, in which two kinds of local resonances, the breathing-type resonance and the Helmholtz resonance, are combined. The thin ring resonator row and slit-type resonator (Helmholtz resonator) row are inserted between two panels of DPS together. Overlapping of the band gaps due to the individual resonances gives a wide and high band gap of sound transmission in the low frequency range. At the same time, the Bragg-type band gap is created by the structural periodicity of the scatterers in the high audible frequency range. In addition, the number of scatterer rows and the filling factor are investigated with regard to the sound insulation of DPS with sonic crystals (SCs). Consequently, the hybrid SC has the potential of increasing the soundproofing performance of DPS in the audible frequency range above 1 kHz by about 15 dB on average compared to DPS filled only with glass wool between two panels, while decreasing the total thickness and mass compared to the counterparts with the other type of local resonant sonic crystal.

2

Design of the test facility for the measurement of noise silencers

Bolejko Romuald, Plaskota Przemysław, Dobrucki Andrzej B., Pruc Krzysztof

Vibrations in Physical Systems

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2022

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Vol. 33, nr 3

art. no. 2022309

EN

In the paper, a description of the test facility designed and implemented for noise silencers according to the methodology specified in the PN-EN ISO 7235 standard is presented. It is possible to measure the insertion loss, flow noise, and pressure loss on the test stand. In particular, the following issues were presented: noise protection in the low frequency range, the design of the anechoic termination, and measurements of the sound pressure level in the flow. To obtain a sufficiently high level of noise protection, three noise transmission paths were considered: direct, indirect, and flanking. The design of the anechoic termination was based on the profile of the catenoid tube, which made it possible to obtain strong sound absorption in the low-frequency range while maintaining a limited length of a terminator. A specially designed microphone cap was used to measure the sound pressure level in the flow field. The paper also presents results of selected measurements that illustrate the possibilities of the designed test stand.

3

Correlation between the shape of substitution ducts and insertion loss of silencers

Wójciak Kamil, Kopania Joanna Maria

Vibrations in Physical Systems

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2022

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Vol. 33, nr 2

art. no. 2022212

EN

Silencers are typical devices used for the reduction of noise in ventilation systems, which can be found in almost all industrial, service or residential installations. Determination of acoustic parameters for specific HVAC devices, like silencers, is within the scope of specialised laboratories. With the silencers, two main parameters should be taken care of: the first one is sound attenuation and the second one is pressure losses. In the presented paper, the focus is on measurement methods described by standard ISO 7235:2009. This standard specifies the methods for determining the sound power level of the flow noise generated by silencers, the total pressure of silencers and the insertion loss of silencers with and without airflow by using the substitute object. In this work, we focused on the correlation between the shape of the substitution duct and its acoustic parameters and its relation to this with the final result of insertion loss of a silencer.

4

Demonstration of a high extinction ratio TiN-based TM-pass waveguide polarizer

Zhao Zhuan, Santi Giovanni, Corso Alain Jody, Pelizzo Maria Guglielmina

Optica Applicata

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2022

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Vol. 52, nr 4

585--598

EN

A high extinction ratio transverse magnetic (TM)-pass plasmonic waveguide polarizer has been designed and optimized. This device exploits two parallel TiN strips embedded in a silicon dioxide cladding to cut off the transverse electric (TE) polarization state, which is either reflected or absorbed, while the TM mode can pass through the main silicon waveguide with significant low losses. Given a device of 5 μm length, an extinction ratio as high as 60.7 dB and an insertion loss of 2.23 dB were achieved at the target wavelength of 1.55 μm. To our knowledge, this extinction ratio is one of the highest values ever reported. In the wavelength of 1.45–1.59 μm, the proposed device provides an optical bandwidth of 140 nm for an extinction ratio more than 30 dB and an insertion loss less than 3 dB. This device is relatively simple and is easier to be fabricated than other architectures that are found in the literature.

5

Wartość tłumienności wtrąceniowej filtrów zasilania urządzeń IT

Nowosielski Leszek, Dudziński Bartosz, Ślubowska Aleksandra Maria

Elektronika : konstrukcje, technologie, zastosowania

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2022

|

Vol. 63, Nr 1

10--15

PL

Współcześnie jednym z podstawowych przedsięwzięć mających na celu minimalizację zagrożenia wynikającego z elektromagnetycznego przenikania informacji jest tłumienie poziomu niepożądanych emisji zaburzeń promieniowanych i przewodzonych generowanych przez urządzenia informatyczne, które mogą być nośnikiem informacji przez nie przetwarzanych. W przypadku emisji ujawniającej przewodzonej najczęściej stosuje się w tym celu filtry cechujące się odpowiednio wysokim tłumieniem wtrąceniowym. W artykule zdefiniowano oryginalną zależność analityczną określającą wymagania na wartość tłumienności wtrąceniowej w dziedzinie częstotliwości wnoszonej przez filtry sieciowe, a także oszacowano wartości parametrów wchodzących w skład zdefiniowanej zależności. Na bazie zdefiniowanej zależności określono wymagania w stosunku do tłumienności wtrąceniowej wnoszonej przez filtry sieciowe, powyżej której wartość stosunku poziomu potencjalnej emisji ujawniającej przewodzonej do poziomu szumów środowiskowych po stronie systemu infiltracyjnego S/N < 0 dB, a w konsekwencji przeprowadzenie infiltracji elektromagnetycznej jest znacznie utrudnione.

EN

At present, one of the main methods of minimizing risk resulting from electromagnetic information leakage is to attenuate the undesired levels of radiated and conducted disturbances generated by IT equipment, as these disturbances can carry information processed by said equipment. Attenuation of conducted compromising emissions is most commonly handled with filters with a sufficiently high insertion loss. This article defines an original analytical relation specifying insertion loss value requirements for mains filters and estimates values of parameters included in the defined relation. Furthermore, this defined relation was used to define requirements for insertion loss provided by the mains filters, above which the ratio value of potentially compromising conducted emission levels to the environmental noise level at the infiltrating system input S/N < 0 dB. As a consequence, electromagnetic infiltration is significantly impeded.

6

Experimental tests of the acoustic properties of sound-absorbing linings and cores of layered baffles

Kosała Krzysztof

Vibrations in Physical Systems

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2021

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Vol. 32, nr 1

art. no. 2021107

EN

The article presents the results of research on the acoustic properties of materials used as sound-absorbing linings and cores in baffles of anti-noise protection. Using an impedance tube the spectral characteristics of the normal incidence sound absorption and sound transmission loss indices of 12 specimens of mineral wool with different density and thickness were determined. From these characteristics, the single-number weighted sound absorption coefficient αw and the sound reduction index Rw were calculated. To calculate the value of the Rw index on the basis of surface mass of the mineral wool specimen, a new formula was proposed. The insertion loss of an acoustic enclosure with one, two and three-layer walls with dimensions of 0.7×0.7 m, containing mineral wool, was determined. The best efficiency was achieved for the enclosure made of walls of layers: mineral wool, placed on the sound source side, steel plate and aluminium plate.

7

Wykorzystanie wartości własnych macierzy impedancji falowych do wyznaczania parametrów cyrkulatorów ferrytowych

Sędek Edward

Elektronika : konstrukcje, technologie, zastosowania

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2020

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Vol. 61, nr 10

27--30

PL

Metoda przedstawiona poniżej została opracowana dla cyrkulatorów paskowych i mikropaskowych z wielostopniowymi transformatorami dopasowującymi, przy czym transformator może zawierać czwórniki mikrofalowe zbudowane z liniowych elementów biernych. W stosowanych dotychczas metodach projektowania cyrkulatorów transformator dopasowujący był uwzględniany dla warunków brzegowych dla składowych stycznych pól E i H na kolejnych nieciągłościach ferryt-dielektryk, dielektryk-dielektryk itd.[2]. Stosowano również metodę obliczeń, opartą na grafie przepływu cyrkulatora [3]. Zarówno w jednym, jak i drugim przypadku występuje znaczna komplikacja zależności opisujących parametry cyrkulatora już dla jednostopniowego transformatora, przy czym komplikacja ta szybko się powiększa dla transformatorów wielostopniowych. Proponowana w tym opracowaniu metoda obejmuje znacznie szerszą grupę układów dopasowujących, przy czym ich liczba praktycznie nie komplikuje zależności końcowych opisujących parametry cyrkulatora. Przedstawiona metoda jest oparta na transformacji wartości własnych macierzy impedancji falowych.

EN

The method presented below has been developed for strip and microstrip circulators with multi-stage matching transformers, and the transformer may contain microwave two ports made of linear passive elements. In the circulator design methods used so far, the matching transformer was taken into account for the boundary conditions for the tangent components of the E and H fields on successive ferrite-dielectric discontinuities, dielectric-dielectric discontinuities, etc. The calculation method based on the circulator flow graph was also used. In both cases, there is a significant complication of the relationships describing the parameters of the circulator already for a single-stage transformer, and this complication increases rapidly for multi-stage transformers. The method proposed in this paper covers a much wider range of matching circuits, with the number of practically no complicated depending on the final parameters that describe the circulator. The presented method is based on the transformation of the eigenvalues of the wave impedance matrix.

8

Influence of geometry of channel on the flow noise parameters

Gaj P., Kopania J.

Mechanics and Mechanical Engineering

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2018

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Vol. 22, nr 2

541--551

EN

Acoustic emission through duct walls is an important problem in engineering acoustics. This phenomenon most commonly occurs in heating, ventilating and air-conditioning (HVAC) and other gas flow ducting (large industrial silencers). Many works focus on elaboration of more exact description of the acoustic field phenomena reflecting the real conditions in which these appliances operate. As a standard, circle or rectangular ducts are used in ventilation systems. However, technical conditions during the installation of the HVAC system, due to the limitation of the assembly space, require often the use of channels with other geometries. This paper presents aeroacoustical parameters of three most common cross-sectional shapes of air-moving ductwork. The rectangular, square with roundedcorners and circular ducts were studied. The "natural" duct attenuation, which is a consequence of duct shape or noise breakout and involves a diminution of the internally propagated sound power was observed. Natural duct attenuation can be a useful way of reducing sound power levels in long runs of duct.

9

Pomiary terenowe skuteczności niskiego betonowego ekranu akustycznego

Dulak L.

Materiały Budowlane

|

2018

|

nr 8

40--43

PL

W artykule przedstawiono wyniki skuteczności niskiego betonowego ekranu akustycznego wyznaczone w badaniach terenowych. Wyniki pomiarów wskazują na konieczność poszukiwania alternatywnych dla PN-ISO 10847 [4] metod wyznaczania skuteczności ekranowania w przypadku specyficznych sytuacji w terenie.

EN

The article presents results of field measurements of insertion loss a low concrete noise barrier. For specific situations in the field, the measurement result smake it necessary to look for methods for determinig the insertion loss that are alternative to PN-ISO 10847 [4].

10

Influence of gold electrodes on the properties of shear horizontal acoustic plate mode viscosity sensor in Bt-cut quartz

Soluch W., Łysakowska M., Wróbel T.

Materiały Elektroniczne

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2017

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T. 45, nr 2-4

3--5

EN

Until now the influence of gold electrodes on the properties of shear horizontal acoustic plate modes (SHAPMs) in BT-cut quartz (-50.5°YX90°) was never before calculated or measured. Calculation presented in this study show that the amplitude of mechanical motion at the quartz plate surface decreases with an increase of the thickness of the gold layer. When the thickness of the gold layer is increased only on one side of the quartz plate, the amplitude decreases on the same side, whereas it remaines unchanged on the opposite side. For one of the SHAPMs, the amplitude of mechanical motion become about twice as big when the gold layer thickness increased from about 0.1 μm to 1 μm. This effect was confirmed by the measurements of the changes of the delay line insertion loss against viscosity of glycerine and water solutions.

PL

Po raz pierwszy wykonano obliczenia i pomiary wpływu złotych elektrod na właściwości czujnika lepkości z poprzecznym horyzontalnym akustycznym modem płytowym (PHaMP) w kwarcu o orientacji BT (-50.5°YX90°). stwierdzono, że amplituda drgań mechanicznych na powierzchni płytki kwarcowej maleje wraz ze wzrostem grubości warstwy złota. Gdy grubość warstwy złota wzrasta po jednej stronie płytki kwarcowej, to zmniejszanie ma miejsce po tej samej stronie, podczas gdy pozostaje niezmienione po stronie przeciwnej. Dla jednego z PHaMP, amplituda drgań mechanicznych zmalała dwa razy gdy grubość warstwy złota wzrosła od 0,1 μm do 1 μm. Efekt ten został potwierdzony przez pomiar zmian tłumienności linii opóźniającej w funkcji lepkości roztworów gliceryny i wody.

11

Surface acoustic wave low insertion loss delay line for applications in sensors

Soluch W.

Materiały Elektroniczne

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2016

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T. 44, nr 1

4--6

EN

It was shown that low insertion loss of a surface acoustic wave (SAW) delay line could be achieved when strong triple transit signals (TTS) are present. As an example, low insertion loss delay line on YZ LiNbO3, was developed. Double electrodes were used in interdigital transducers (IDTs) and in a screen. At a frequency of 62 MHz, insertion loss of about 8 dB, was obtained. Low insertion loss and narrow bandwidth make this SAW delay line attractive for applications in physical and gas sensors.

PL

Wykazano, że mała tłumienność wtrącenia linii opóźniającej z akustyczną falą powierzchniową (AFP) jest możliwa do uzyskania, gdy występuje silny sygnał trzeciego echa (STE). Jako przykład, opracowana została linia opóźniająca na podłożu YZ LiNbO3. W przetwornikach międzypalczastych i w ekranie zastosowano podwójne elektrody. Na częstotliwości 62 MHz uzyskano tłumienność wtrącenia około 8 dB. Mała tłumienność wtrącenia i wąskie pasmo czynią tę linię atrakcyjną do zastosowań w czujnikach fizycznych i gazowych.

12

Solution of some problems of single-scale wavelet transform processor using a magnetostatic surface wave device

Lu W., Kuang L., Lü X., Zhu C., Zhang T., Zhang J.

Metrology and Measurement Systems

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2012

|

Vol. 19, nr 4

685-692

EN

In this paper, we investigate the implementation schemes of a single-scale wavelet transform processor using magnetostatic surface wave (MSSW) devices. There are three implementation schemes: the interdigital transducer, the meander line transducer and the grating transducer. Because the interdigital transducer has excellent properties, namely, good frequency characteristic and low insertion loss, we use the interdigital transducer as the implementation scheme of a single-scale wavelet transform processor using MSSW device. In the paper, we also present the solutions to the three key problems: the direct coupling between the input transducer and the output transducer, the insertion loss, and the loss characteristics of the gyromagnetic film having an influence on the wavelet transform processor. There are two methods of reducing the direct coupling between the input transducer and the output transducer: increasing the distance between the input transducer and the output transducer, and placing a metal "wall" between the input transducer and the output transducer. There also are two methods of reducing the insertion loss of a single-scale wavelet transform processor using a MSSW device for scale: the appropriate thickness of the yttrium iron garnet (YIG) film and the uniform magnetic field. The smaller the ferromagnetic resonance linewidth of the gyromagnetic film, the smaller the magnetostatic wave propagation loss.

13

Models of Elements for EMI filters

Zachar J., Drinovsky J., Kejik Z., Ruzek V.

Przegląd Elektrotechniczny

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2011

|

R. 87, nr 12a

205-208

EN

This paper deals with the modeling of the EMC filter in wide frequency range. The filter model is created from the models of the EMI filter components. At higher frequencies spurious elements of the components have large influence, which is necessary to describe in the models. EMI filter is composed of the LC low pass structures. Spurious elements of the individual components have a significant effect on the attenuation characteristics.

PL

Przedstawiono metody projektowania filtru EMI dla szerokiego zakresu częstotliwości. Punktem wyjścia są modele komponentów filtru. Przy wysokich częstotliwościach ważną rolę odgrywa uwzględnienie wpływów zjawisk pasożytniczych.

14

A proposal for 1×8 all-optical switch using multimode interference

Bahrami A., Rostami A.

Optica Applicata

|

2011

|

Vol. 41, nr 1

165--172

EN

We propose an eight-channel all-optical switch using a multimode interference phenomenon. This structure is based on the cooperation of self imaging and self guiding in nonlinear multimode interference. The switching operation is done with changing the intensity of the input signal. To the best of our knowledge, this is for the first time that a 1×8 all-optical switch is presented based on a continuous multimode interference region. Simulation results show low crosstalk and high efficiency in the output profiles. The mean values of the crosstalk and the insertion losses in eight states of the switching operation are -33.8 dB and -0.16 dB, respectively. Full-vectorial beam propagation method is used for the simulation of the device.

15

The choice of suitable fitness function for optimization spurious elements of EMI filters

Kejik Z., Drinovsky J., Ruzek V., Zachar J.

International Journal of Microelectronics and Computer Science

|

2010

|

Vol. 1, nr 2

211-217

EN

In Introduction are introduced main problems of measurement of EMI filter and is suggested that creation of model of EMI filter is useful. In this paper is shown model of EMI filter which is based on basic circuitry of the EMI filter. Reduced equivalent circuitries for EMI filter and his creation are also shown, because these circuitries are more suitable for usage in iteration optimization loop. The spurious elements of filter are searched with optimization. Participial swarm optimization is used. Two possibilities of fitness function calculations are shown, too. Results of both approaches are compared in this paper. Using fitness function with weight coefficients gives better results and this fitness function is used for optimization of the measured characteristics.

16

Insertion Loss of Spiral Ducts - Measurements and Computations

Łapka W.

Archives of Acoustics

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2009

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Vol. 34, No. 4

537-545

EN

This work presents measured and computed characteristics of insertion loss (IL) of spiral ducts. Numerical and experimental models of spiral ducts have been investigated. For the numerical modeling, a three dimensional model computed by the use of a finite element method in a COMSOL Multiphysics computer application has been used. For the experimental modeling, there has been made a spiral duct model by using a three dimensional rapid prototyping technique. An acoustic system with a round silencer has been ivestigated, and the spiral duct has been inserted at the inlet. IL is considered in this paper as the difference between the sound pressure level (SPL) [dB] probed at only one outlet point of the acoustic system without and with an acoustical filter (spiral duct), respectively. The results of measured and computed IL of spiral ducts presented in this paper confirm the fact that this newly discovered technical solution for attenuating sound in ducted systems has an applicable potential. There are visible small discrepancies between the measurements and computations. The results can differ due to the non ideal dimensions of the experimental model and the non ideal inlet and outlet surroundings of the experimental acoustic system. However, the IL characteristics of the computed model is almost wholly covered by the IL characteristics of the measured model.

17

Wybrane zagadnienia analizy tłumienności wtrąceniowej rdzeni magnetycznych

Wac-Włodarczyk A., Mazurek P.

Przegląd Elektrotechniczny

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2008

|

R. 84, nr 2

114-116

PL

Artykuł przedstawia analizę tłumienności wtrąceniowej rdzeniowych dławików przeciwzakłóceniowych. Zaproponowano rozbudowany, równoległy schemat zastępczy (elementy pasożytnicze). W modelu wykorzystano zespoloną przenikalność magnetyczną rdzenia, uzależnioną od częstotliwości. W artykule zawarto fragment weryfikacji przeprowadzonych symulacji z wynikami pomiarowymi.

EN

The article presents the analysis of the insertion loss of cores and EMI chokes. Expansion, parallel equivalent circuit diagram was proposed (parasitic elements). The complex magnetic permeability of core in model was contained. The part of article presents the verification of simulation with measurements.

18

Wpływ przenikalności magnetycznej rdzeni dławików przeciwzakłóceniowych na tłumienność wtrąceniową

Mazurek P., Wac-Włodarczyk A.

Przegląd Elektrotechniczny

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2007

|

R. 83, nr 9

73-75

PL

Artykuł przedstawia analizę tłumienności wtrąceniowej rdzeniowych dławików przeciwzakłóceniowych. W prezentowanym modelowaniu dławika wykorzystano równoległy schemat zastępczy dławika, uwzględniający zjawiska pasożytnicze. Jako kluczowy parametr, wykorzystano zespoloną przenikalność początkową materiału rdzeniowego. W pracy zamieszczono wybrane wyniki przeprowadzonych symulacji i badań laboratoryjnych.

EN

The article presents the analysis of the insertion loss of cores and EMI chokes. Expansion, parallel equivalent circuit diagram was proposed (with parasitic elements). The complex magnetic permeability of core in model was contained. The part of article presents the verification of simulation with measurements.

19

Analiza tłumienności wtrąceniowej rdzeni ferrytowych i nanokrystalicznych

Wac-Włodarczyk A., Mazurek P.A.

Przegląd Elektrotechniczny

|

2005

|

R. 81, nr 12

19-21

PL

Przedstawiony artykuł prezentuje porównanie tłumienności wtrąceniowej rdzeni ferrytowych oraz nanokrystalicznych wykorzystywanych w ochronie przeciwzakłóceniowej obwodów zasilania.

EN

These papers presented analyze the insertion loss of ferrites and nanocrystalline cores. The simulations and measurements values of insertion loss are discussed in this paper.