Радиофизика и электроника (Dec 2017)
ANTENNAS WITH CONTROLLED DIRECTIVITY PATTERNS
Abstract
The current methods and devices for correcting and controlling the directivity patterns of metal whip and loop reconfigurable antennas, as well as plasma and electron beam reconfigurable antennas are investigated. It is proposed to solve the problem of effective correction and control of antenna directivity patterns by changing their design and incorporating concentrated reactive loads and switches into the shoulders of antennas. Similar problems are proposed to be solved by the creation of reconfigurable antennas based on cold plasma or streams of moving electrons with switched on information signal and power switches. The results of calculations of Z-shaped and rhombic antennas with controlled radiation patterns with lumped loads and switches included in radiating conductors are presented. The results of studies of the gain factor and the standing wave coefficient with respect to the voltage of the antennas with corrected and controlled radiation patterns are presented. It is noted that unlike metallic reconfigurable antennas and antenna arrays in plasma and electron-beam antennas, there are more opportunities to control radiation patterns and other electrical parameters by creating so-called "conducting paths" in them. In this case, the disconnected conductive paths no longer affect the operation of the antenna. In reconfigurable plasma and electron-beam antennas, it is proposed to plan and program in advance the activation and deactivation of the necessary "conducting paths" at given time periods in order to obtain the required directional patterns. The results of the calculation of directional patterns and other electrical parameters of a metallic collinear antenna array of the Franklin–Marconi type and a plasma eight-element reconfigurable antenna are presented. A variant of a new electron-beam reconfigurable antenna is presented. The results of the research are given in the form of a table and graphs. It is noted that metal, plasma and electron-beam reconfigurable antennas are promising for use in radio engineering systems, including terrestrial, marine and aerospace telecommunications and radiolocation systems.
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