Thus, the aims and tasks of this thesis are:
| — | - Develop the mathematical model of a printed-circuit radiator of an irregular shape within a periodic antenna array based on the successive reflection method. |
| — | Develop the software based on the mathematical model in order to analyze the antenna arrays of printed-circuit radiators. |
| — | Use the developed software to assess the convergence rate of the iterative procedure serving as a basis for the mathematical model, propose methods making it possible to improve the convergence and also carry out a series of numerical experiments in order to determine the characteristics of a number of printed-circuit antenna arrays. |
| — | Evaluate the possibility of using a multilayer ribbon antenna array as a radio-absorbing coating. In order to achieve this aim, develop the mathematical model and software and analyze the characteristics of this metal-dielectric structure assessing its wideband and wide-angle characteristics. |
| — | Build the mathematical model of near-omnidirectional antenna systems located on finite screens of an irregular shape. Analyze how a finite screen of an irregular shape affects the radiation pattern characteristics of an antenna system. |
The scientific newness of the thesis comes down to the following:
| — | The mathematical model of an antenna array consisting of printed-circuit radiators with a radiation plate of a random shape based on the successive reflection method has been developed. |
| — | The iterative procedure the successive reflection method is based on has been modified, which makes it possible to increase the convergence rate of the method, the convergence of the iterative procedure for the devices with ohmic losses and/or dielectric losses has been proved. |
| — | The option of building the antenna curtain of a multilayer ribbon antenna array that possesses the ultrawideband properties and can be used as a radio-absorbing coating has been examined. |
| — | The two-dimensional mathematical model of a scattering object that can be used to analyze how finite screens of an irregular shape affect the radiation pattern of antennas has been developed. |
The mathematical model of an antenna array consisting of printed-circuit radiators with a plate of a random shape developed during the work on this thesis makes it possible to significantly reduce the dimension of the problem being solved as compared to the element approach. The efficiency of the method is significantly higher if the modified iterative procedure is used. The results of the mathematical modeling of printed-circuit radiators over a conducting screen of an irregular shape are implemented in the All-Russian Research Institute of Radio Engineering (ARRIRE) during the development of the Vostok antenna system. The abovementioned results served as a basis for selecting the geometric shape and size of the conducting screen of the antenna on the control channel of the ground-based radio requester, which makes it possible to build the necessary shape of the radiation pattern, reduce the amount of experimental research and the time needed to develop the antenna. The fact of applying the results of the thesis is confirmed by the implementation certificate.
