scholarly journals A new shielding effectiveness measurement method based on a skin-effect transmission line coupler

2007 ◽  
Vol 5 ◽  
pp. 37-42 ◽  
Author(s):  
T. Kleine-Ostmann ◽  
K. Münter ◽  
T. Schrader
Keyword(s):  
Transmission Line ◽  
Cross Section ◽  
Measurement Method ◽  
Skin Effect ◽  
Test Material ◽  
Shielding Effectiveness ◽  
Scattering Parameters ◽  
Low Frequencies ◽  
Outer Conductor ◽  
Effectiveness Measurement

Abstract. We propose a new convenient material shielding effectiveness measurement method based on a skin-effect transmission line coupler. The method is somewhat similar to the arrangement with two coupled TEM cells known from literature. The transmission line coupler consists of a pair of identical transmission line 2-port devices. Each device contains a coaxial waveguide, with a circular inner conductor and an outer conductor having a square cross section. One side of the outer conductor is left completely open as a slot. The slot is surrounded by a large metal housing to contact the two halves. As a measure for the shielding effectiveness the coupling between the two devices is measured in terms of scattering parameters after the test material is brought between the two halves. The devices can be used in a range from low frequencies to a few GHz.

Determination of The Scattering Parameters of Fittings in Industrial Buildings for Use in Computer Based Factory Noise Prediction Models: Part 2 – Scale Model Experiments

1995 ◽  
Vol 2 (3) ◽  
pp. 527-548 ◽  
Author(s):  
H.A. Akil ◽  
D.J Oldham
Keyword(s):  
Cross Section ◽  
Measurement Method ◽  
Prediction Models ◽  
Scattering Cross Section ◽  
Noise Prediction ◽  
Scattering Parameters ◽  
Reverberation Chamber ◽  
Scattering Cross ◽  
Industrial Buildings ◽  
Computer Based

In a companion paper results obtained from computer simulation1 have demonstrated that the sound propagation characteristics of disproportionate rooms are determined by the product of the fitting parameters scattering cross-section (Q) and absorption coefficient (αobst) of fittings. It was also proposed that the absorption of a fitting as measured in a conventional reverberation chamber is equivalent to four times the product of those two parameters. This suggests that measurement of fitting absorption in a conventional reverberation chamber could provide the data required for input into current computer based factory noise prediction models. Since both parameters are required as inputs to computer models it would be necessary to separate them in some way from the data obtained in the reverberation chamber. In this paper two methods for determining the scattering parameters of fittings in industrial buildings based upon acoustical measurements are described. The accuracy of these is compared with that resulting from the application of a geometrical measurement method to determine the scattering cross-section (Q) of various shapes of model scatterers employed in experimental work employing 1:20 acoustic scale models. The values of Q obtained from each method were used to predict sound characteristics a model disproportionate chamber using RAYSCAT. The predicted results obtained from the computer model by inputting the values of Q determined using the acoustical measurement methods were found to be more accurate than those using the geometrical measurement method.

The scaled RCS measurement method for lossy targets via dynamically matching the reflection coefficients in the THz band

2021 ◽  
Author(s):  
Shuang Pang ◽  
Yang Zeng ◽  
Qi Yang ◽  
Bin Deng ◽  
Hong-Qiang Wang
Keyword(s):  
Cross Section ◽  
High Frequency ◽  
Measurement Method ◽  
Dielectric Material ◽  
Frequency Estimation ◽  
Estimation Method ◽  
Physical Optics ◽  
Reflection Coefficients ◽  
Effective Solution ◽  
Terahertz Band

Abstract In the terahertz band, the dispersive characteristic of dielectric material is one of the major problems in the scaled radar cross section (RCS) measurement, which is inconsistent with the electrodynamics similitude deducted according to the Maxwell’s equations. Based on the high-frequency estimation method of physical optics (PO), a scaled RCS measurement method for lossy objects is proposed through dynamically matching the reflection coefficients according to the distribution of the object’s facets. Simulations on the model of SLICY were conducted, the inversed RCS of the lossy prototype was obtained using the proposed method. Via comparing the inversed RCS with the calculated results, the validity of the proposed method is demonstrated. The proposed method provides an effective solution to the scaled RCS measurement for lossy objects in the THz band.

scholarly journals SHIELDING EFFECTIVENESS OF MULTIPLE-SHIELD CABLES WITH ARBITRARY TERMINATIONS VIA TRANSMISSION LINE ANALYSIS

2016 ◽  
Vol 65 ◽  
pp. 93-102 ◽  
Author(s):  
Salvatore Campione ◽  
Lorena I. Basilio ◽  
Larry Kevin Warne ◽  
Howard Gerald Hudson ◽  
William L. Langston
Keyword(s):  
Transmission Line ◽  
Shielding Effectiveness ◽  
Line Analysis

Shielding effectiveness analysis of rectangular cavity with aperture by modification and expansion of transmission line method

2013 ◽  
Vol 25 (9) ◽  
pp. 2355-2362 ◽  
Author(s):  
彭强 Peng Qiang ◽  
周东方 Zhou Dongfang ◽  
侯德亭 Hou Deting ◽  
余道杰 Yu Daojie ◽  
胡涛 Hu Tao ◽  
...  
Keyword(s):  
Transmission Line ◽  
Rectangular Cavity ◽  
Shielding Effectiveness ◽  
Line Method ◽  
Effectiveness Analysis ◽  
Transmission Line Method

scholarly journals Experimental study of microwave properties of composites filled with Permalloy powder

2018 ◽  
Vol 185 ◽  
pp. 02002
Author(s):  
Stanislav Y. Bobrovskii ◽  
Victor A. Garanov ◽  
Andrei S. Naboko ◽  
Alexei V. Osipov ◽  
Konstantin N. Rozanov
Keyword(s):  
Ferromagnetic Resonance ◽  
Skin Effect ◽  
Magnetic Loss ◽  
Spherical Particles ◽  
Loss Peak ◽  
Low Frequencies ◽  
High Frequencies ◽  
Permittivity And Permeability ◽  
Powder Particles ◽  
Shape Data

Frequency dependencies of permittivity and permeability of composites filled with Permalloy powder with various concentrations and shapes of particles have been measured and discussed. The powder particles of various shapes were obtained by mechanical milling of industrial Permalloy powder in organic media. Paraffin wax was used as a matrix for producing the composites. A shape data of the particles was obtained with an electron microscope. The permittivity and permeability were measured in the frequency range of 0.13 to 10 GHz. The shape of the particles changes from sphere to platelet with increase of milling time. The change leads to a shift of the ferromagnetic resonance (FMR) frequency and magnetic loss peak. It is shown that for larger particles, a decrease of the Q-factor of the ferromagnetic resonance is observed, which is explained by the strong influence of the skin effect. With increase of the concentration of the Permalloy particles in composite, the magnetic loss peak shifts to low frequencies. When the spherical particles are flattened, the resonance frequency shifts to high frequencies, which indicates that the shift to high frequencies due to the decrease of the skin effect and the change in the magnetic structure is stronger than the shift to the low frequencies by changing the shape and reducing the demagnetization.

Sign in / Sign up

Export Citation Format

Share Document