The use of genetic algorithms to maximize the performance of a partially lined screened room

This paper shows that it is possible to use genetic algorithms to optimize the layout of ferrite tile absorber in a partially lined screened enclosure to produce a "best" performance. The enclosure and absorber are modeled using TLM modeling techniques and the performance is determined by comparison with theoretical normalized site attenuation of free space. The results show that it is possible to cover just 80% of the surface of the enclosure with ferrite absorber and obtain a response which is within +/-4 dB of the free space response between 40 and 200 MHz

A rectangular waveguide cell for measurement of the shielding effectiveness of anisotropic materials

A method for measuring the shielding effectiveness of planar anisotropic materials using a rectangular waveguide cell is proposed. Computational models are used to verify the behaviour of the cell and validate its ability to measure shielding effectiveness. Results of measurements on a control sample and three carbon-fibre composite laminates in a GTEM cell are presented. A dynamic range of 70 dB with a capability to discriminate 20 dB of anisotropy is achieved in the frequency range 400-1600 MHz using cubic cells of side length 200 mm and 300 mm

Coupling of Energy Into PCB Traces in a Reverberant Environment: Absorption Cross-section and Probability of Susceptibility

Predicting the risk of susceptibility to electromagnetic interference for a system would be of significant interest to the EMC community. In this paper, we consider the coupling of electromagnetic energy into Printed Circuit Board (PCB) traces and how it relates to the power balance model of shielding effectiveness. We show results of some measurements of the absorption cross-section of a load on a PCB trace and compare them with previously published results

A method for the measurement of shielding effectiveness of planar samples requiring no sample edge preparation or contact

A method is presented for the measurement of shielding effectiveness of planar materials with nonconducting surfaces such as carbon fiber composites. The method overcomes edge termination problems with such materials by absorbing edge-diffracted energy. A dynamic range of up to 100 dB has been demonstrated over a frequency range of 1-8.5 GHz, depending on the size of the sample under test. Comparison with ASTM D4935 and nested reverberation measurements of shielding effectiveness shows good agreement

Characterization and modelling of electromagnetic interactions in aircraft

This article describes the development of modelling techniques and simulation tools for the electromagnetic (EM) analysis of aircraft. It is shown that hybrid solvers and multi-scale techniques can be used effectively to analyse the EM response of aircraft. The importance of supplementing models with appropriate measurement and characterization techniques for parameter extraction and for validation is also demonstrated

Experimental characterization of the response of an electrical and communication raceway to IEMI

This paper reports the results of two experimental campaigns aimed at studying the high-frequency response of a raceway containing low voltage power, telephone, and Ethernet cables, to external electromagnetic field illumination. The raceway was tested against HPEM transients inside a GTEM cell and low power fields inside a reverberation chamber (RC). The HPEM tests revealed that the low voltage power cables have the greatest coupling under a hyperband illumination, compared to telephone and Ethernet cables. The RC tests allowed the determination of statistical transfer functions from random incident field configurations into DM voltage in cable loads. The responses were found to be governed by the raceway under test at the lower frequencies (below 1 GHz). Between 0.2-1 GHz, the raceway gives about 10 dB higher coupling than a short patch cable. The difference is even greater at lower frequencies and for shielded cables. In the frequency band 1-3 GHz, little difference was observed between short patch cables and the full raceway, but both were still significantly higher than direct coupling to the measurement card. Beyond 3 GHz, the coupling is clearly dominated by the terminal equipment. The experiments performed in this work provide a better understanding of the expected induced voltages and currents in commercial cable systems when exposed to IEMI-like signals

A Lightweight, Compact, High voltage Hyperband Antenna for IEMI Testing

A robust lightweight antenna for testing immunity of equipment to intentional electromagnetic interference (IEMI), based on a planar Vivaldi design, is described, along with simulated and measured test results

A 150MHz, High Voltage Mesoband Dipole Antenna for IEMI Testing

An antenna for testing immunity of equipment to intentional electromagnetic interference (IEMI) is described, along with simulated and measured test results which show a good agreement and demonstrate the high-voltage operation

A 1.3 GHz, High Voltage Mesoband Dipole Antenna for IEMI Testing

A resonant dipole antenna for testing immunity of equipment to intentional electromagnetic interference (IEMI) is described, along with simulated and measured test results which are in good agreement and demonstrate the high voltage operation