Fourier transform analysis for waveguide bends, parallel slits, and flanged parallel-plate

Abstract

The solution for various waveguide types such as bend, double bend, and folded short are obtained in analytic forms. Bends are essential devices in virtually all waveguide microwave systems, such as radar seekers, satellite beam-forming networks. The derivation from T-junction to bend is also included. The analysis for double bend in microwave system can be extended to the very small device where quantum effect occurs, since a similarity exists between Helmholtz equation and Schrodinger equation. A folded short in rectangular waveguide is often used in waveguide design when a space limitation does not allow the use of a standard waveguide short. A fast-converging series solution for scattering from the folded short is obtained and its characteristics are presented. The scattering characteristics for H-plane and E-plane shorts are included with the results of the other methods. The mode-matching technique is used to enforce the boundary conditions and the residue calculus is utilized to obtain the scattered field in rapidly-convergent form. In chap. 2, we analyze the various type of waveguide using the Fourier sine transform when the TE-wave is incident. Chap. 3 describes the Fourier cosine transform in case of the incident TM-wave. In chap. 4, we discuss the scattering and mutual coupling from slits in thick parallel conducting screens. Electromagnetic scattering from slits in two parallel conducting screens has been extensively studied for its practical applications to EMI/EMC/EMP. More extensive theoretical works were performed using the Wiener-Hopf techniques and the moment-method. The purpose of the investigation in chap. 4 is to study the behavior of scattering from a finite number of slits in thick parallel conducting screens and to investigate the radiation field and mutual coupling between two waveguides having the same axis. The analysis of this chapter can be extended to a scattering problem having a transverse shift. The simple transmission line the...