Metasurfaces for Far-Field Radiation Pattern Correction of Antennas under Dielectric Seamed-Radomes

A high-index dielectric radome seam is camouflaged with respect to a low-index dielectric radome panel by tuning the seam with carefully engineered metasurfaces. A transmission-line approach is used to model the metasurface-tuned seam and analytically retrieve the corresponding surface impedance, from which the unit-cell design is then tailored. Full-wave simulations and microwave antenna measurements performed on a proof-of-concept prototype validate the undesired scattering suppression effect in the case of normally and obliquely incident transverse electric and transverse magnetic wave illuminations. Robustness of the proposed solution to fabrication tolerances is also reported. The study presents metasurface-tuning as an easily implementable, frequency adjustable, and polarization insensitive solution to reduce the scattering of dielectric mechanical seams and improve the overall transparency performance of radome structures.

Study on the Effect of Material Absorption of Photonic Crystals on Transverse Magnetic Wave Band

<p align="justify">Photonic crystals are a major discovery in physics and have an important influence on our present life. The biggest feature of the photonic crystals is that they have bandgap which can block photons of a certain frequency, thus affecting the photon movement. This effect resembles the influence of the semiconductor body on electrons. Therefore, research and discovery of the photonic crystal have a broad prospect and people have large expectation on the photonic crystal. The emergence of photonic crystals makes it possible for the miniaturization and integration of some aspects of information technology. Their structure studies enable us to determines their characteristics, thus the discovery of the photonic crystal structure and function will lay the foundation for the study of its application. In this paper, the study focuses on the research of material absorption of photonic crystal on Transverse Magnetic (TM) wave band. Firstly, the basic knowledge and principle of photonic crystal are introduced. Then, the research is carried out to study the effect of characteristic matrix method on photon crystal TM energy wave. </p><p align="justify"> </p>

Computational modeling of hypersingular integral equations for 2D pre-cantor scattering structure

<p>This paper presents the investigative study to derive a computational model based on hypersingular integral equations for the pre-Cantor plane-parallel diffraction structure. Such structure consists of finite numbers of the thin impedance strips located in the XY plane. A plane transverse magnetic wave is incident from infinity on considered diffraction structure at an angle and need to find the total field resulting from the scattering. The model which is considered in this work is an approximation of real fractal antennas in two-dimensional case. Pre-fractal properties of grating allow producing the newest antennas for modern mobile devices due to their compact size and broadband properties. The purpose of this work is to develop computer model their structure using parametric representation of hypersingular integral operator, Nystrom method with specific quadrature formulas. The numerical results have been obtained and investigated for pre-Cantor structures for calculating physics characteristics. These results have been compared and analyzed in different mathematical models and softwares.</p>