A. A. Volkov, I. A. Syrbu

Attention to the questions of radiation of the electromagnetic fields of ultra short durations (nano- and picosecond range) is caused by the necessity of decision of row of actual tasks of the applied character, major from which are tasks of ultra wideband radio-location and connection, and also radio electronic suppression of radio electronic facilities. Logoperiodic antenna, possessing the known property of ultra wideband, is one of perspective types of emitters of ultra short impulses. Calculation models absent presently, settings intercommunication between the geometrical parameters of logoperiodic antenna, required descriptions of the radiated electromagnetic field and parameters acting on the entrance of aerial of excitant impulse. The purpose of work consists of development of methods of calculation of spatio-temporal dependence of tension of electric-field of logoperiodic antenna in the distant area of radiation at impulsive excitation of aerial. The set problem is decided by the vectorial adding up of the fields of vibrators, making aerial, taking into account geometry of their location along an axis aerials which in turn was examined as an aggregate of elementary doublets. Distribution of currents along vibrators was determined approximately on the theory of the balanced lines. Electromagnetic co-operation of vibrators was not taken into account. On the worked out methods the calculations of the radiated field are conducted in various directions for a few values of durations of excitant impulse at geometrical preset parameter of aerial. It is set on results calculations, that the form of the field impulse depends on direction on a view point, and also dependence of the directed properties of aerial is set on duration of excitant impulse. At shortening of pulse width of tension of generator the level of radiation decreases in main direction, the level of back radiation increases, and a maximum of radiation is displaced in direction, perpendicular to the axis of antenna. The article includes 7 drawings and references to 9 sources of information.