SHIELDING ANALYSIS OF A METALLIC ENCLOSURE
The prediction of the shielding performances of metallic enclosures used for telecommunication devices is an important part of the global design process. The desire for a reduced time-to-market means that there is often no time or budget for performing extensive prototyping and test measurements. These limitations make the reliable computation and prediction of the shielding properties of a given structure critical. The CST MICROWAVE STUDIO® (CST MWS) Transient solver was used for the simulations which provides time and broadband frequency data from a single simulation.
Figure 1: CST MWS model geometry.
The shielding properties of an actual metallic rack have been simulated with CST MICROWAVE STUDIO® (CST MWS). Figure 1 shows a view of the CST MWS model of the metallic rack. A plane wave is used to illuminate the rack with monitor probes defined inside the rack for recording the electric field in order to allow the shielding effectiveness (SE) to be evaluated.
Figure 2 shows a photograph of the designed rack as well as the experimental set-up.
Figure 2: Photograph of the metallic rack and experimental setup.
Figure 3: S11 and S21 comparison between measurements and CST MWS simulations
The equivalent electromagnetic model was validated by means of measurements of S-parameters as shown in Figure 3 . Excellent correlation between simulation results and measurement can be seen.
Figure 4: CST MWS 3D equivalent electromagnetic models
A sensitivity analysis on SEy is then performed and 4 cases are studied:
1) The enclosure is perfectly closed but with the connector holes open.
2) The cover is screwed on and the connectors metallically closed
3) The same configuration as in case 2, but with a dielectric material introduced between the cover and the walls to represent the presence of the gasket
4) The enclosure has a floating cover placed at a distance of 0.1mm from the lateral walls. All connectors are metallically closed as shown in Figure 4.
The Shielding effectiveness (SE) frequency spectra results are presented in Figure 5.
Figure 5: SEx and SEy spectra
In this article the effect of various geometries and configurations on the shielding effectiveness of a metallic enclosure was investigated. The validation of the numerical model used for the SE computation is demonstrated by comparing the results of the CST MWS Transient solver simulations with experimental results. Excellent agreement could be seen in the comparison. The Transient solver is dieal for such simulation since it provides broadband frequency results in just one simulation. In addition, the time domain variation of fiueld quantities can also be extracted from the simulation.
CST Article "SHIELDING ANALYSIS OF A METALLIC ENCLOSURE "
last modified 9. Jul 2007 11:55
printed 4. Jul 2008 3:27, Article ID 263
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: 263
Last modified: 9. Jul 2007 11:55
Other Articles
Optimisation of Microwave Plasma Sources with the transient, frequency domain and eigenmode solvers of MAFIA.
Read full article..
Metamaterials are a new class of man-made materials that can be engineered to respond to electromagntec fields in unconventional ways. The response of a material to an EM field is described by permittivity and can be tuned in meta-materials to assume negative values. This means that the material can reverse the phase of propagating waves and are commonly referred to as left-handed materials (LHM). A famous concept of LHM -the Split Ring Resonator (SRR) consists of periodic metallic structures controlling EM-properties on a macroscopic scale. The model presented here consists of a coplanar waveguide (CPW) periodically coupled to SRRs forming a bandpass behaviour.
Read full article..
CST MICROWAVE STUDIO® and Agilent ADS have been successfully employed in this OEIC driver design - an example of a high speed analog/broadband IC application.The package model was imported from Agilent momentum and the model was simulated upto a 100 GHz in CST MWS.The resulting eye diagrams of the driver design from CST MWS are compared with those from Agilent momentum and other test cases.
Read full article..
A standardized spherical phantom head such as the one described in this example is commonly used for SAR investigations and measurements.
Read full article..
For a customer given corrugated horn the phase center has been computed using CST MICROWAVE STUDIO® and compared with measurement data. The simulated results are in very good agreement with measurements. Measurements were provided with courtesy and permission of Kathrein Werk KG, Rosenheim, Germany.
Read full article..