This Research Initiation Award project will study the electromagnetic scattering and radiation from impedance surfaces in the presence of dielectric materials and analyze some new antennas and scatterers. The proposed study will be based on the use of the surface integro-differential equations to generate different formulations. While exact boundary conditions will be applied on the dielectric surfaces, the concept of the impedance boundary conditions will be introduced on the impedance surfaces. The use of this concept provides the means for modeling different surface types of practical significance such as complex composite objects. The solution will be carried out numerically using the method of moments. The solution accuracy will be established through comparison with other available analytical and numerical results as well as new experimental data. Many problems will be investigated such as the internal resonance problem. The proposed approach is particularly useful in studying the radiation and scattering from axisymmetric complex composite objects such as the new microslab antenna. the microslab antenna is similar to the microstrip one except that the conducting patch is replaced by a physically thin disc of high dielectric constant to reduce the conduction losses from the radiating conducting patch. The study of the radiation characteristics of microslab antennas will be carried out numerically and experimentally. Different excitation techniques are also under consideration for economic use in the phased array antennas.
