On the Active Region of the Log Periodic Dipole Antenna

Abstract

A method for determining the active region of the log periodic dipole (LPD) antenna is suggested. It is difficult to determine exactly the dimensions of the active region of the LPD because it depends on various design parameters such as α, σ, τ, etc. However, for a fixed value of α and τ, a criterion has been evolved to determine the active region of the LPD. It is found that the active dipole region lies between the resonant dipole and any dipole having length between 0·3 and 0·38 λ.