Near Fields And Surface Fields Analysis On Complex Electromagnetic Objects

This paper is a special study on the near fields and surface fields of complex electromagnetic objects. As we all know, the study on radiate fields has made remarkable progresses in these days, however, studies on near fields and surface fields are still underway. On the other hand, this topic has special important significance on Electromagnetic Compatibility (EMC) and Electronic Confrontation of complex electromagnetic environment. Further studies on near fields and surface fields will be of great value in the near future. Complex electromagnetic objects mainly include thin wire antennae, open objects, closed objects, wire-surface junction and antennae in the presence of conducting objects. For this purpose, two techniques are performed at the same time, one is integral equation based Pulse Expansion ?Point Matching method (PEPM), the other is Piecewise Sinusoidal Reaction Formulations (PWSRF). The author抯 major contributions are as follows. 1. The Generalized Ohm抯 Law is used in solving problems as linear antennae excited by complex source networks. In doing so, linear antennae theory is combined with network theory, and separations between linear antennae and networks are avoided. 2. The Electric Dipole Approximation technique is proposed in calculating rapidly and accurately near fields of linear units and surface patches with constant current distributions. Linear interpolation technique is used in solving the near fields of linear current units. The advantage of this method over NEC2 is presented after a comparison between them. The less segments may lead to good accuracy by using this method. In addition, the Electric Dipole Approximation technique is rapid than the two-fold integration method when calculating near fields a little far away from the sources. 3. A rapid hybrid technique is developed which is used to calculate the surface fields of perfect conducting surface structures. Virtues of the Electric Dipole Approximation technique and Kemptner抯 method are combined which leads to high accuracy and rapid calculations. 4. Near fields formulations for rectangular surface patches with piecewise sinusoidal current distribution are presented here. Surface fields of the patches can also be obtained by using this rigorous formulations expressed in terms of complex exponential integrals. Moreover, the influence of linear charges, which are very important in many situations, is discussed in these formulations. 5. One-fold integral expressions of the self I mutual impedance of coplanar, parallel and orthogonal surface monopoles under Piecewise Sinusoidal (PWS) current distribution are presented here at the first time. In contrast to references available, PWS basis functions here are with a cosine transverse variation. These expressions are more challenging because there is closed forms for surface fields. With the techniques provided here, a highly accurate impedance matrix can be obtained rapidly. 6. Rectangular attachment is put forward in order to solve the case when the feed point is near to the border of the conducting surface. it is deserved to mention that this new model is more simply than the one developed by Dr. Chen Qiang and both of them can obtain high accuracy. Most of results in this paper have been performed in the practice.