Acoustic and electromagnetic wave scattering from multi-junctions have been investigated in the literature.
In chapter 2, acoustic scattering from a hybrid junction in a rectangular waveguide is studied. The Fourier-transform and mode matching is used to represent the scattered wave and the simultaneous equations for the modal coefficients are formulated. A residue calculus is utilized to obtain a solution to the simultaneous equations in fast-converging series. Numerical computations are performed to show the behavior of transmission in terms of junction geometry and operating frequency. The utility of acoustic hybrid junction is discussed in terms of its decoupling characteristics.
In chapter 3, TM-wave radiation from a stepped-parallel-plate waveguide aperture is studied. The Fourier-transform and mode matching is used to represent the scattered wave and the simultaneous equations for the modal coefficients are formulated. The residue calculus is utilized to obtain a solution in fast-converging series. Numerical evaluation shows the behavior of reflection in terms of the step geometry and operating frequency. Comparison with a right-angled flanged parallel-plate waveguide aperture shows good possibility to use a steppedparallel-plate as a matching structure.
In chapter 4, electromagnetic wave radiation from an obliquely-flanged parallel-plate waveguide is studied. The Fourier-transform/series and Green's formula is used to represent the scattered wave and the simultaneous equations for the modal coefficients are formulated. Residue calculus is utilized to obtain a fast-convergent series solution. Numerical evaluation shows the behaviors of transmission, reflection, and radiation in terms of junction geometry and operating frequency.
In chapter 5, TM and TE wave transmission of an oblique parallel-plate waveguide array is studied. The scattered wave is represented in terms of continuous and discrete modes based on the Fourier transform and series, respectively. The tangential field continuities at the boundary are enforced to obtain simultaneous equations for the discrete modal coefficients. Residue calculus is utilized to transform the radiation field and the reflection coefficient into numerically-efficient forms. Numerical computations are performed to illustrate the behavior of wave radiation and reception by an oblique waveguide array.
