Yu. S. Rusov - Ph.D. (Eng.), Head of Department, Research Institute of Radio Electronic Technology, Bauman Moscow State Technical University. E-mail: rusov.yu.s@gmail.com

Dielectric waveguide radiators are widely used in waveguide elements of phased array antennas. One of the most important antenna radiator characteristics is the reflectivity which depends on scanning angle. The reflectivity essentially depends on array antenna radiator construction and conducting screen plane position in the array antenna aperture area. Dielectric waveguide radiator characteristics subject to scanning angle and conducting screen plane position may be determined by the solution of the electromagnetic waves on the infinite two-dimensional periodic array antenna diffraction problem. To research the reflectivity dependence on conducting screen plane position the in line with round waveguide coaxial waveguide is included in the array antenna cell. The coaxial waveguide shorting plane is the model of the conducting screen positioning on the distance Lк from the waveguide aperture plane. The H11 mode reflectivity in the process of waveguide excitation is found by solving electromagnetic waves on longitudinally homogeneous regions joints diffraction problem. Mode matching method is applied. The transverse field components boundary conditions are written for each joint of longitudinally homogeneous regions. Electromagnetic field in each longitudinally homogeneous region is presented in expanded form of eigenwaves of the region. To find the field decomposition coefficients the problem has resolved into solution of the linear algebraic equations system. To find transversely inhomogeneous oblique form Floquet channel eigenwaves the first order differential operator and Galerkin method are applied. The eigenwaves are found in expanded forms of basic functions. Eigenwaves of the uniform Floquet channel are used as the basic functions. The solution convergence and applicability for research of the array antenna characteristics dependence on conducting screen position in the dielectric waveguide array antenna aperture area are considered. Comparison of the results obtained with the presented solution and with other methods is carried out. The conducting screen plane position reflectivity dependences obtained with different methods have the same character. The described solution may be used to research the reflectivity dependence on conducting screen plane position.