Features computation diagram of annular direction antenna arrays what made on half-wave vibrators located above cylindrical surface.

Abstract

The use of antenna-feeder devices, especially installed on moving objects, indicates the need to modernize and develop new type antenna devices to increase the efficiency of the radio communication system in conditions of active radio electronic suppression. One of the options for providing interference protection in communication channels with moving objects is the use of narrowly directed Smart antennas with a controlled directional pattern. Smart antennas, which are also called intelligent antennas, are one of the varieties of phased antenna arrays. Smart antennas use a set of radiating elements built in the form of grids. The most widespread are the ring antenna arrays, which are characterized by their compactness and great functionality. The relevance of the task of designing Smart antennas is to reduce the total number of emitters without degrading the antenna parameters. This task is particularly important for antennas with circular radiation patterns in communication systems with moving objects. The obtained results clearly show the possibilities of ring antenna arrays layout, depending on the radius of the antenna array and the radius of the cylindrical support, and under which conditions the geometric dimensions of the ring antenna arrays will preserve the coefficient of uniformity of the directional pattern. In order to reduce the number of vibrators in such antennas, the maximum distance between the vibrators is usually found, at which the uniformity of β directional diagrams does not decrease below a given level. To find the permissible distance, you can calculate the dependence of β on the radius of the grating directly when calculating the azimuthal directional diagrams of the antenna. To solve this problem, the external characteristics of the ring antenna arrays performed on half-wave symmetric vibrators in ideal conditions and vibrators placed over a cylindrical surface were considered.