Design and Realization of a Linearly Polarized Eleven Feed for 1-10 GHz

A new linearly polarized eleven feed for operation between 1 and 10 GHz is presented. This frequency band is higher than the realized before, and the input reflection coefficient is better than ${-}8$ dB over the frequency range, which also is an improvement over previous models. The log-periodic dipole petals have been designed by using a simple one-by-one parameter optimization scheme with a simulation tool based on moment method. The final analysis has been improved by applying an finite-difference time-domain (FDTD)-based solver for the central part of the feed and then a circuit network program to combine the results of the center part with the result of the dipole panels. The antenna has been manufactured by printed circuit board (PCB) technology on a metalized Kevlar sheet in order to obtain better tolerances and smaller dimensions than in previous models. Measurements show agreement with the analysis.