V.I. Nikolaev, Y.B. Nechaev, A.S. Ryakhovsky

In this paper the ways of directed antennas creation with the narrow directional diagram in the vertical plane and various types of directional diagram in the horizontal plane - from one-sector to multisector and circular diagrams - are offered. Magnetic current distribution generation is the basis of the technique in the lateral aperture of the cylindrical cavity exited by internal electric vibrators and gives the directional radiation similar to array application. The mathematical model of such cavity operation which assumes the two steps task solution is offered. At the first step the electrodynamics internal problem is solved. The integral equations system for finding of electric current distribution on the cylinder internal surface which is decided by collocation method is obtained for this structure. At the second step is the magnetic current distribution in an aperture. The expressions for electric field intensity in a distant zone are obtained according to the current distribution. This model allows to find the narrow range of values of geometrical parameters in which the directional features show up and to optimize geometrical and electrodynamic characteristics. Furthermore antenna electrodynamic parameters on the basis of the circular cylinder with one open lateral wall are investigated. It is established that diameter of the cylinder ~ 0,7 λ is optimal. Electrodynamic parameters of cavity-excited antennas with other forms of cavities differing from the circular one are investigated and optimized. The ways of these antennas parameters improvement and other secondary radiation antennas are offered.