Effect of the Shape of the Protrusion of the NRD- Waveguide Rod on the Characteristics of the Node

The improvement of communication systems and navigation devices is based on the development of integrated functional units of millimeter wavelengths. Flat structures consisting of metal and dielectric structures deserve special preference. In the EHF range, a promising solution is a section of the regular NRD waveguide line. Special attention in the design of microwave technology is given to the study of shapes and shapes of waveguide structures. In this paper, the influence of the shape and appearance of the projection of the dielectric rod on the transfer characteristics is considered. As part of the work, using applied modeling packages, patterns of electromagnetic fields for three protrusion shapes were obtained and the nature of wave processes was assessed. On the basis of a physical experiment, the dependences of S parameters with the studied area in the Ka range were studied, which showed an increase in losses with an increase in the size of the protrusion. At the same time, the shape of the protrusion affects the nature and frequency of failures. The triangular shape represents a smooth transformation of the wave and, with an increase in the length of the irregularity, shows the smallest dips in the transfer characteristic, and the round shape has a high indentation due to the mode conversion. The obtained research results can be used in the construction of filters based on a periodic structure, the shape of which will be chosen depending on the requirements for the characteristics of the node.