Gain and Directivity Analysis of the Log Periodic Antenna

Lusekelo Kibona

Abstract: In telecommunication, a log-periodic antenna is a broadband, multi element, directional, narrow-beam antenna that has impedance and radiation characteristics that are regularly repetitive as a logarithmic function of the excitation frequency. The lengths and spacing of the elements of a log-periodic antenna increase logarithmically from one end to the other. This antenna design is used where a wide range of frequencies is needed while still having moderate gain and directionality. In this paper the directivity, electric field, gain and axial ratio were investigated and analyzed by using twelve elements with spacing factor of 0.7 and wavelength of 6m, where the directivity and its gain were observed to be increasing when the elements of the log periodic antenna were increased at the active region of the RF.

Keywords: log periodic antenna, directivity, gain, far field, electric field