Broadband antenna with reactive elements for mobile objects

The subject of broadband antenna development is one of the key and topical issues of research in antenna technology. In conditions of antenna installation on mobile objects and the need to ensure operation in the VHF and UHF ranges, the choice of a possible antenna type and broadband matching method is carried out taking into account many factors, including design and weight and size limitations. The use in this case of such classic types of broadband antennas as log-periodic or discone is limited, primarily due to the fact that their broadband properties are realized with overall dimensions comparable to the wavelength for the lower frequency of the operating range. The broadband of linear configuration antennas, in general, can be achieved by additional matching networks and baluns, optimization of the geometric shapes of radiators, combining balanced dipole and unbalanced whip radiators, as well as including reactive elements in radiator body. The question of the technological feasibility of certain solutions is considered separately for specific tasks, however, the inclusion of reactive elements in a body of a linear radiator, in the case of its implementation, both from pipes and from a conductor or wire, has significant technological advantages. This approach is widely covered in the literature using inclusions with inductance coils. At the same time, a large number of such inclusions can significantly reduce the efficiency of the antenna. As an alternative, it is advisable to consider the possibility of using inclusions based on capacitors. The aim of the work is to study the possibilities of using inclusions based on capacitive reactive elements in the antenna body in a linear design to achieve a given bandwidth. The obtained results demonstrate the possibility of successful matching of whip antennas in a wide frequency range using reactive inclusions (capacitors) in the radiating system. Such a solution is applicable both in the case of developing an antenna with a single radiator and in the case of developing complex composite radiators. The presented research results can be used in the development of broadband antennas.