Computer Simulation Technology
 
CST

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.


Real view of the metallic rack
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.


Real view and CST MWS model of the used loaded monopole antenna
Figure 2: Real view and CST MWS model of the used loaded monopole antenna


S11 parameter of the 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.


Comparison between measured results and simulated (CST MWS) results
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 10. Feb 2012 10:58, 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.

Other Articles

Five-Section Microstrip Hairpin-Filter

Five-Section Microstrip Hairpin-Filter
The example design is a classic hairpin filter with a bandwidth of 3.6 to 4.3 GHz. The hairpin filter was designed for a return loss better than -20dB across the band. CST DESIGN STUDIO™ was used to design and tune the filter, the resulting layout was then verfied with the 3D- EM simulation software CST MICROWAVE STUDIO®. Read full article..

Using CST MWS for Signal Integrity problems

Using CST MWS for Signal Integrity problems
This article is concerned with the important issue of Signal Integrity and the application of CST MICROWAVE STUDIO® to the investigation of the characterisation of an SMA connector on a multi-layer PCB. Read full article..

Wake Field Simulation of a Beam Position Monitor

Wake Field Simulation of a Beam Position Monitor
This article shows how the wake field solver of CST PARTICLE STUDIO™ can be used to simulate a beam position monitor in the pick-up mode. The used beam position monitor is a quarter wavelength electrode similar to the one used in the Electron Storage Ring (ESR) of the Gesellschaft für Schwerionenforschung (GSI) Darmstadt. Read full article..

Antenna Placement on a Box

Antenna Placement on a Box
In this article the new I! Solver of CST MICROWAVE STUDIO® is used to calculate the input impedance of a monopole antenna on a conducting box. This simple example demonstrates the accuracy of the Integral Equation Solver. Geometry and results are from the paper "The Input Impedance of a Monopole Antenna Mounted on a Cubical Conducting Box“ by Shyamal Bhattacharya, Stuart A. Long, Donald R. Wilton. IEEE Transactions on Antennas and Propagation, Vol. AP 35, No. 7, July 1987. The Read full article..

Radar Cross Section and Surface Current Simulation for a Helicopter

Radar Cross Section and Surface Current Simulation for a Helicopter
We present the RCS and surface current simulation for an electrically large helicopter. The simulation is done using a plane wave excitation at 7GHz. The helicopter is approximately 180 wavelengths in size. The calculation is performed with the Integral Equation solver of CST MICROWAVE STUDIO® using the Multilevel Fast Multipole Method. The solver is very accurate and efficient in terms of complexity for simulating electrically large structures. Read full article..

Back