Radome Electromagnetic Theory and Design

Chapter 2Sandwich Radomes

Radomes are used as electromagnetic (EM) windows and are made of multilayer structures commonly called sandwich radomes. Usually, their geometrical shape is conformal and designed to protect the enclosed antenna from environmental hazards and be transparent to electromagnetic energy transmitted or received through them. The shape of a radome is determined by a combination of considerations, which include mechanical, thermal, aerodynamics, environmental, and electromagnetics. However, if the radome curvature is large enough in terms of wavelength, the interaction problem between the antenna fields and the radome surface can be locally considered as a problem of an electromagnetic plane wave with arbitrary polarization and oblique incident angle illuminating a planar multilayer structure extending to infinity in the x-y plane and being finite in z direction.

Section 2.1 illustrates the analogy between the analysis of a multilayer sandwich radome and its transmission line model. This analogy is important because it enables us to use all developed tools and concepts in transmission line analysis for the sandwich radome design. In section 2.2, the analysis is extended to a multilayer structure, and in sections 2.3 to 2.6, the analysis focuses on particular cases such as single layer slab, A-sandwich, B-sandwich, and C-sandwich, respectively.

2.1 Transmission Line Analogy

The propagation direction of the incident plane wave with respect to the z-axis is ...