Study of design features of radio engineering systems with radio channels

Abstract

The article reviews the peculiarities of the formation of the architecture of radio technical systems with radio channels. The problems of this study are revealed, it is emphasized that due to natural influences, the radiating surface of the antenna is deformed, changing the spatial amplitude-phase distributions of the excitation sources corresponding to the directional diagrams. It is emphasized that the modern mathematical synthesis of frame antennas does not allow obtaining solutions with the necessary accuracy for antennas consisting of curved conductors or located in close proximity to other objects, as well as in the case of an antenna array. It is proposed to use the principle of replacing the spatial directional diagram with its approximate representation in the form of a product of functions describing single-plane directional diagrams in the main sections. The mathematical apparatus of this approach is outlined and the need to connect the center of the antenna with the center of a circle with a radius equal to the distance from this center to the observation point is described. The module of the reflection coefficient at the input of the antenna is graphically presented according to the results of numerical modeling, according to the results of which it was established that in order to shift the resonant frequency of the antenna to the desired range, it is necessary to increase the total capacity of the capacitors included in the circuit. The ways of modification of planar capacitors are characterized, according to the selected option, a conclusion is made regarding the significant deterioration of the characteristics of the second sample. Additional numerical calculations were carried out and, as a result, a graphical dependence of the distribution of the normal (with respect to the antenna plane) component of the magnetic field intensity vector was obtained for the two samples under consideration. It is noted that despite the geometrically uniform arrangement of additional capacitor lines, their introduction to the structure leads to significant unevenness in the distribution of the surface current along the perimeter of the frame and a significant decrease in its amplitude in individual areas of the antenna. An additional situation was simulated when a chip capacitor with a capacity of 0.82 pF was added near the power point to the gap of the main conductor, and the distance between the substrate and the screen was reduced to 25 mm. The effectiveness of this approach has been proven, a slight increase in the registration distance has been noted, which is explained by the improvement of the alignment of the antenna with the power line.