The scope of application of a reciprocity principle in the theory of antennas at radiation and reception of ultra-wideband signals

An antenna for a reception of the signals, which have spatial length much less than physical length of the antenna and the processes occurring in this antenna, are considered. On an example of the elementary antenna - the symmetric vibrator - features of ultra-wideband (UWB) signals' reception are shown and dependence of a current's form in loading of the antenna from a positional relationship of transmitting and reception antennas is described. It is shown, that change of the form of a field of transmitting antenna from change of a positional relationship of antennas does not allow using a reciprocity principle for construction of the reception antenna's pattern. Physical interpretation of the processes occurring in the antenna is given. The field's pattern is given at excitation of the antenna by the UWB signal. Non-stationary character of these diagrams is shown. As the basic characteristic of the UWB antenna for practical appendices the pattern on energy is considered.