The input impedance of an electrical vibration generator has been defined as a ratio of the voltage in the gap to the current in the feed point; complex current distributions along the half–wave and full–wave vibration generator for various vibration generator radiuses normalized to the wavelength have been estimated; dependency charts for the real and imaginary components of the input impedance of the electrical vibration generator from the branch length of the vibration generator normalized to the wavelength for various values of the vibration generator radius normalized to the wavelength.