The geometrical theory of diffraction (GTD) is an efficient method of analysis and design of wave fields. It is widely used in antenna synthesis in microwave, millimetre and infra-red bands, in circuit engineering and laser system design. It is a convenient tool for tackling the problems of wave propagation and scattering at bodies of complex shape. The method combines the simplicity and physical transparency of geometrical optics with high computational accuracy over a wide dynamic range of quantities analysed. The advantage of GTD is particularly pronounced in applications where the wavelength is small compared with the typical size of scatterers, i.e. in situations where the known analytical techniques - variational calculus and numerical analysis - are no longer applicable.
This book painstakingly systematises the ideas underlying GTD, gives a detailed explanation of the modern state of the theory within the bounds of its validity, and elucidates its relationships with other popular asymptotic theories - the methods of physical optics and edge waves.
The book is designed for scientists, engineers and postgraduate students involved in electromagnetics, radio engineering and optical system design.
The continuous development of the Geometrical Theory of Diffraction (GTD), from its conception in the 1950s, has now established it as a leading analytical technique in the prediction of high-frequency electromagnetic radiation and scattering phenomena. Consequently, there is an increasing demand for research workers and students in electromagnetic waves to be familiar with this technique. In this book they will find a thorough and clear exposition of the GTD formulation for vector fields. It begins by describing the foundations of the theory in canonical problems and then proceeds to develop the method to treat a variety of circumstances. Where applicable, the relationship between GTD and other high-frequency methods, such as aperture field and the physical optics approximation, is stressed throughout the text. The purpose of the book, apart from expounding the GTD method, is to present useful formulations that can be readily applied to solve practical engineering problems. To this end, the final chapter supplies some fully worked examples to demonstrate the practical application of the GTD techniques developed in the earlier chapters.