tailieunhanh - Fundamentals of Engineering Electromagnetics - Chapter 10

Các thuật ngữ tương thích điện từ (EMC) là viết tắt của các chi nhánh của kỹ thuật đối phó với các phân tích và thiết kế của các hệ thống tương thích với môi trường điện từ của họ. Nó có thể được cho rằng có hai loại kỹ sư-những người có vấn đề EMC và những người sẽ sớm có. Tuyên bố này minh họa tác động của EMC thực hành kỹ thuật hiện đại. Vấn đề can thiệp không phải là mới. Kể từ khi bắt đầu của các kỹ sư vô tuyến nhận thấy những khó. | 10 Electromagnetic Compatibility Christos Christopoulos University of Nottingham Nottingham England . SIGNIFICANCE OF EMC TO MODERN ENGINEERING PRACTICE The term electromagnetic compatibility EMC stands for the branch of engineering dealing with the analysis and design of systems that are compatible with their electromagnetic environment. It may be claimed that there are two kinds of engineers those who have EMC problems and those who will soon have them. This statement illustrates the impact of EMC on modern engineering practice. Interference problems are not new. Since the beginning of radio engineers noticed the difficulties encountered when trying to make ground connections to the chassis of different systems and the onset of whistling noise attributed to atmospheric conditions. All these are manifestations of electromagnetic interference EMI and demonstrate the need to design systems which are compatible with their electromagnetic environment. There are two aspects to EMC. First systems must be designed so that they do not emit significant amounts of unintended electromagnetic EM radiation into their environment. This aspect is described as emission and may be divided in turn into conducted and radiated emission. Second systems must be capable of operating without malfunction in their intended environment. This aspect is described as immunity or alternatively as susceptibility. Hence all EMC analysis and design techniques aim to address these two aspects using circuit-based and field-based experimental analytical and numerical techniques. It is important to realize why EMC has become so important in recent years. As is usual in such cases there are several reasons Modern design relies increasingly on the processing of digital signals . signals of a trapezoidal shape with very short rise and fall times. This gives them a very broad frequency spectrum and thus they are more likely to interfere with other systems. Most modern designs rely on clocked .