Shielding Performance of a Metallic Rack used for Telecommunication Equipment : Simulation and Measurements
The rule regarding the electromagnetic immunity and electromagnetic interference of electronic devices increases the importance of a careful design of shielding enclosures. The prediction of the shielding performance of a metallic rack used for telecommunication devices it has been always a critical point of the global design process. Aim of the present paper is to apply to evaluate the electric field radiated from a defined metallic rack when a source is located inside it. A view of the opened metallic rack is shown in Fig. 1.
Figure 1: Real view of the metallic rack
Fig. 2 depicts a real view and the correspondent electromagnetic model of the loaded monopole antenna used to perform measurements inside a semi-anechoic chamber. The antenna consists on two disks of radius r=48mm, thickness t=0.5mm, distant 1mm one each other and separated by a dielectric material with relative electric permittivity epsilon=8. The leg length is h=95mm, and the first resonance frequency is at 0.65GHz, as confirmed in Fig.3.
Figure 2: Real view and CST MWS model of the used loaded monopole antenna
Figure 3: S11 parameter of the loaded monopole antenna.
The results obtained by means of measurements are presented in Fig. 4 where the vertical and horizontal (Ex and Ey) electric field components registered 3m distant from the metallic opened rack are compared with the corresponding results coming from the numerical simulation.
Figure 4: Comparison between measured results and simulated (CST MWS) results
Very good agreement with the measured results is achieved; this is a clear indication of the effectiveness of numerical modeling of EMC and shielding problems since it allows an analysis to be performed on the model and its general performance to be investigated even before the prototyping stage of the structure.
CST Article "Shielding Performance of a Metallic Rack used for Telecommunication Equipment : Simulation and Measurements"
last modified 27. Jun 2006 5:47
printed 4. Jul 2008 3:26, Article ID 269
URL:
All rights reserved.
Without prior written permission of CST, no part of this publication may be
reproduced by any method, be stored or transferred into an electronic data processing system, neither mechanical or by any other method.
Article ID: 269
Last modified: 27. Jun 2006 5:47
Other Articles
This article examines the modelling of lightning strikes using CST MICROWAVE STUDIO® (CST MWS). The surface current distribution due to a double-exponential form lightning strike on the nose of an airplane is calculated by way of example.
Read full article..
This application note describes the use of CST MICROWAVE STUDIO® in optimising the geometry of a free standing nested annular slot type Frequency Selective Surface (FSS). An isolation of better than 20 dB between the 316.5-325.5 GHz and 349.5-358.5 frequency bands was achieved in both the TE and TM planes for a 45 degree incident plane wave, while the insertion loss was below 1 dB.
Read full article..
This huge Pillbox Antenna was optimised by one of our customers even during the evaluation period of CST MICROWAVE STUDIO
Read full article..
This article summarises the simulation of a System-in-Package (SiP) model using the CST MICROWAVE STUDIO® (CST MWS) Transient Solver to determine the S-Parameters, field distribution and system response when excited with 10 and 20 GHz pulses with additional noise signals. An analysis of the SiP with a board mounting and its effect on the is resonant frequency is also performed. The EMC behaviour of the SiP with and without the mounted board is also considered.
Permission and courtesy of AET Inc. Japan.
Read full article..
In this article a single periodic open-ended waveguide phased-array antenna with a dielectric radome at its aperture of variable thickness is analysed. As a verification it is shown that the superposition of two independent plane waves shows the same field pattern as the one created by the unit cell model.
Read full article..