Analysis of circular-to-circular groove waveguide junction

Mode matching method is used to analyze the scattering characteristics of thecircular-to-circular groove waveguide junction. Matching the electric fields and magnetic fields atthe boundary of the junction, and multiplying the mode functions of the circular waveguide andcircular groove waveguide on both sides of the boundary equation, the scattering matrix equation isobtained, the scattering coefficients can be obtained from the equation. Then the scatteringcharacteristics of the iris with circular window in circular groove waveguide are analyzed. At lastthe convergent problem is discussed; when choosing a suitable mode group, convergent numericalresults are obtained, and the frequency response of the iris' scattering coefficients is also given.

A novel four-legged loaded element thick-screen frequency selective surface with a stable performance

A thick-screen frequency selective surface （FSS） has not only a broad bandwidth but also the advantages of overcoming the multilayer FSS shortcoming of complex structure and low transmittance of centre frequency due to the cascade of FSSs, and this means it could potentially be applied in a stealth curved streamlined radome. However, there is an unsteadiness of centre frequency in a wide range of incident angles and another unsteadiness of polarization in a big incident angle. In order to solve these problems, in this paper we provide a novel four-legged loaded element thick-screen FSS. The structure is analysed and simulated using the mode matching method and moment method. The centre frequency, the transmittance of centre frequency, and bandwidth of the structure are investigated when some parameters including the polarization at a big incident angle and the incident angles of TE ＆： TM waves are changed. The novel four-legged loaded element thick-screen FSS has better transmission properties with a better steadiness of polarization and incident angle independence. The novel structure of the four-legged loaded element thick-screen FSS provides a valuable reference for their application in a stealth curved streamlined radome.

Scattering Characteristics of Metallic Plates in Radial Waveguide

Mode matching is a useful method to analyze the mode characteristics during the section change of a waveguide. By applying this method to the radial waveguide, and solving specific problems due to the radial transmission of electromagnetic wave, this presents a calculating method in radial waveguide based on mode matching. The scattering characteristics of metallic plates in the radial waveguide are calculated, and verified qualitatively using an electromagnetic simulator, which confirmed the validity of this method.

Some Techniques for Computing Wave Propagation in Optical Waveguides

Optical wave-guiding structures that are non-uniform in the propagation direction are fundamental building blocks of integrated optical circuits.Numerical simulation of lightwaves propagating in these structures is an essential tool to engineers designing photonic components.In this paper,we review recent developments in the most widely used simulation methods for frequency domain propagation problems.