The historical summary in Chapter. 1 outlines some pnor works on the relevant
areas such as Wood anomaly. Bragg and off-Bragg blazing phenomena and the
guided leaky wave . and their limitations. Rectangular groove reflection grating is studied extensively for th Bragg-angle blazing and the off-Bragg blazing. when the Bragg-angle blazing means that all the incident power is scattered back into the direction of incidence which equals the first order Bragg backscattering angle. Off- Bragg blazing means that its scattered wave propagates in the direction different from the Bragg backscattering angle. An experimental study of the plane wave scattering from the periodic strip grating on a grounded dielectric slab showed the Bragg blazing. Little attention is given to the off-Bragg blazing nor the relationship between the scattering and the leaky wave radiation by the periodic strip grating on a grounded dielectric slab.
Chapter 2 then. describes the analysis method for the electromagnetic scattering
by the geometry for the TE(Transverse Electric) case from the viewpoints of both the reflection grating and the leaky-wave antenna problems. The induced electric current density on the strip as unknowns is expanded into a product of a series of Chebyshev polynomials and a function satisfying edge condition. Galerkin ' s scheme is employed for testing. Fast convergence of solution is illustrated in comparison with the point matching method. Numerically calculated results for Bragg-angle blazing are presented and compared with previous experimental results, Some interesting characteristics ofthe Bragg blazing as well as Off-Bragg blazing are observed in the structure. In particular, it is pointed out that the Bragg-angle blazing may be of two types, one associated with the guided leaky wave and the other not relevant to it. It is also found that the off-Bragg blazing phenomena exists only if the leaky wave is guided by the present geometry. The existence of the off-Bragg blazing phenomena in the present geometry is an interesting result since the off-Bragg blazing has not been reported in the conventional reflection gratings such as rectangular groove grating, echelete grating. and holographic grating within sinusoidal profile.
In Chapter 3. T1\I-polarized electromagnetic wave scattering IS considered with
that for the guided leaky wave. Equivalence principle is utilized to retain the same formulation for TE polarization. The numerical results of the plane wave scattering around the blazing angle are presented and compared with those of the experimental works of Fair et al.. Some characteristics of the Bragg as well as Off-Bragg blazing phenomena are discussed.
In Chapter 4. scattering and radiation problems of electromagnetic waves in the
case of oblique incidence and arbitrary polarization are analysed in the spectral domain with sampling. Some numerical examples are shown for the surface current
distributions and the variation in the power of significant scattered modes for the case of the arbitrary polarization and oblique incidence. Numerical results exhibit a good convergence even for a small truncation number. In particular. the Bragg as well as the off-Bragg angle blazing phenomena in the case of arbitrary incident angle and polarization are discussed from the viewpoints of both the reflection grating and the leaky-wave antenna in detail. In addition, the relationship between the Bragg blazing and characteristic mode of the surface current in the strip is pointed out.
Chapter 5 concludes and further problems are discussed In Chapter 6.
