Computer Equipment, Electromagnetic Compatibility Characteristics Of Numerical Simulation

During modern social development,electronic devices have been uesd in all kinds of domains, which give birth to a increasingly complex electromagnetic environment. Engineers need analyze electromagnetic radiation from electronic devices for optimizing configuration, shortening design time and reducing product cost. Throughout the world, EMC (Electromagnetic Compatibility) simulation is a essential process during electronic devices design period. Throughout EMC simulation, the EMC problems can be found and solved before product on stream, which can shorten design time and force product to come into the market quickly. In the paper, the numerical simulation method for EMC structural design and modeling of electronic devices has been studied in details by TLM ( Transmission-Line Matrix Method ) in electromagnetic field. The works carried out in the paper can be summarized as follows:1. The theory of TLM in electromagnetic field is studied in details. The apertures are modeled and simulated by the two-dimensional TLM shunt node and three-dimensional TLM symmetrical condensed node(SCN) modeling method.2. The shielding effectiveness of computer enclosure apertures is researched based on TLM in electromagnetic field by a computer enclosure with apertures. The far field and near field electromagnetic leakages of the aperture arrays,seam and fan on computer enclosure are simulated and researched in coupling microstrip radiant field for the first time. The electromagnetic interfere in far field is simulated in the planar waves. The enclosure improved shielding configurations are simulated and researched.3. The equivalent circuit analytical formulas are researched for calculating the shielding effectiveness in the cases of multi-holes in the two faces. Then it expands the formulas to deal with the cases of multi-holes with different types in the same face in the paper, Konefal characteristic impedance model and Farhana characteristic impedance model are used improve the equivalent circuit analytical formulas. The compare between TLM simulation and formulas result indicate that the improved equivalent circuit analytical formulas are correct. 4. The theory of ESD (Electro-Static Discharge) equivalent circuit model is introduced in the paper. The electromagnetic fields generated by ESD are simulated by TLM in electromagnetic field. The coupling characteristics between the ESD electromagnetic fields and 2U shielding configurations are researched in details, which include aperture shapes,double perforated plate and so on.