RADAR Cross Section (RCS) is the magnitude that allows to quantify the reflective power of an object, or on the contrary its electromagnetic discretion. In this work, we intend to calculate the RSC of some two-dimensional structures in a homogeneous dielectric material. But first of all, we should begin by studying the theoretical basis of integral equations which allow to reach the calculation of this quantity, which is the RCS. We will describe the theoretical foundations on which the TEHD digital program is based and which we have developed to calculate the RCS of undefined cylindrical dielectrics upon which falls an incident TE wave (E_Z= 0).
Electromagnetic waves can be emitted into the open space by an antenna; it is called free propagation of waves, a process that is widely used in telecommunication systems [1]. When the frequency and / or the power increases, the use of transmission lines is very limited by the appearance of higher order modes that occur as soon as the transverse dimensions of the structures used are no longer negligible compared to the wavelength and also by increasing dielectric losses in the insulators which also often causes an important attenuation [2] in this case, it becomes necessary to use structures called generally "waveguide" for the transmission of this electromagnetic energy. It's about a hollow conductor in which electromagnetic waves are propagated by successive reflections on the internal walls. The metal waveguides are the basis for the design of many microwave devices such as filters, transformers, adapters, polarizers.... In this chapter we'll have a detailed overview on the use of waveguides (filters in general), their characteristics, advantages, disadvantages compared to other guiding structures.