Log-periodic antennas with in-phase currents

Abstract

The approximate method of calculating directional characteristics of log-periodic antenna: directional patterns, directivity, and pattern factor is proposed. The analytical expressions are determined, and characteristics of antennas with straight metal dipoles and with in-phase radiators of the same dimensions are calculated. The advantage of using in-phase radiators is demonstrated. It is shown that the log-periodic antennas of radiators with in-phase current distribution allow to decrease the antenna length and to provide the high directivity in a wide frequency range. The problem of optimization of considered antennas by methods of mathematical programming is stated.