Frequency independent parabolic phased antenna array of log periodic antennas

A frequency-independent phased array antenna made of log-periodic radiators is presented which, in contrast to the Duhamel array, does not employ phase shifters at the antenna inputs to produce radiation in the main direction. The array considered here is a system of radial log-periodic radiators that form a parabolic phased-array antenna. The dipoles of all the radiators having the same size are located along a parabolic line. The operation of the parabolic array at various frequencies is equivalent to that of a series of confocal parabolic mirror antennas excited from a single source.