Second-Order Perturbative Solutions for 3-D Electromagnetic Radiation and Propagation in a Layered Structure With Multilayer Rough Interfaces

We present a fast method for deriving a general explicit closed-form expression of second-order perturbative solutions of the problem of radiation and propagation electromagnetic (EM) fields in a hybrid layered structure with an arbitrary number of rough interfaces and planar stratified medium based on the classical small perturbation method (SPM). The second-order SPM expression of the electric and magnetic fields in each region of the rough-layered structure is provided by theoretical analysis and fully formula derivation instead of considering any other approximation and equivalent process. In addition, we give the complete understanding of physical radiation and propagation mechanism of double-bounce second-order SPM solutions. Finally, the second-order SPM solutions derived by employing the proposed method are verified with existing methods and numerical results. What is more, we investigate completely the influence of various parameters of layered structure and configuration of radar system on EM scattering fields.