A.M.T. Al-Mamoori1, S.N. Shabunin2

1,2 Ural Federal University named after the First President of Russia B.N. Yeltsin (Ekaterinburg, Russia)

1 University of Diyala (Baqubah, Iraq)

1 adnanalmamory@gmail.com

Huygens elements play a crucial role in analyzing radiation patterns emitted by various antennas, particularly aperture antennas, which function as fundamental emitters. These antennas find extensive applications, including their use as radar sensors. A common challenge arises when these sensors are situated close to reflective surfaces, significantly complicating the calculations related to their radiation fields. The existing software tools that facilitate these calculations often require considerable computational resources, which can be a limitation in practical scenarios. In this article, the authors endeavor to develop a comprehensive model of an emitter whose radiation field is significantly influenced by the proximity of a reflecting surface. The study addresses the intricate problem of radiation emitted from Huygens elements in a scenario with a media interface. The authors employ a rigorous electrodynamic formulation that leverages Green's functions specifically tailored for layered structures in a Cartesian coordinate system to tackle this. This methodology enables the precise computation of the electromagnetic fields, encompassing all field components at any given point in space, including within the near-field region of the antenna. The near field is characterized by the fact that the radiation pattern has not yet fully stabilized, making this a challenging aspect to analyze. To validate the reliability and effectiveness of the derived expressions, the authors conducted a limiting case study transitioning to free space. This involved calculating the radiation field utilizing the Saddle Point method, a powerful technique in asymptotic analysis. The electromagnetic field calculations are executed through numerical integration over wave numbers in the complex plane, allowing for robust and accurate results. The universality of this methodology is underscored by the incorporation of the medium structure beneath the interface in the characteristic part of the Green's functions, which facilitates the analysis of materials possessing diverse electrophysical properties. The article also details specific calculations for the electric field components emanating from the Huygens element located in the region situated between the radiator and the interface with the medium. The calculations were performed with the emitter strategically positioned at a height of 2.5 wavelengths above the reflecting surface. For this investigation, an open-end rectangular waveguide was selected as a representative example of a Huygens element. The results obtained from these analyses provide a clear and insightful physical interpretation of the radiation characteristics. Moreover, by selecting either electric or magnetic current sources as the emitter configuration, researchers can effectively analyze and interpret the radiation profiles of various types of printed and slit antennas when they are placed in proximity to reflective surfaces. This work not only enhances the understanding of antenna behavior in complex environments but also contributes valuable insights into the design and optimization of antenna systems for practical applications.

The research was executed by a Grant from the Ministry of Science and Higher Education of the Russian Federation (Project N 075-03-2023-006).

Al-Mamoori T.A.M., Shabunin S.N. Use of Huygens element in solving the problem of aperture antenna radiation near the interface
by the method of Green's functions. Radiotekhnika. 2025. V. 89. № 4. P. 129−143. DOI: https://doi.org/10.18127/j00338486-202504-12 (In Russian)

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