Design and Modelling of Printed Log Periodic Dipole Array Antenna with Different Feeding Methods

This paper presents the design and analysis of a traditional printed log-periodic dipole array antenna with two feeding methods: direct feeding and straight coaxial feeding. Ten linear dipoles have been arranged in logarithmic style to cover an operating frequency bandwidth from 0.7 GHz to 2.3 GHz with a direct feeding method. At the same time, the same structure offered impedance bandwidth from 0.7 GHz up to 8 GHz with a coaxial feeding method. Moreover, the results showed that the coaxial cable method has lower antenna gain than a direct feeding method. Two different insulator materials have been utilized in the simulation of the coaxial cable feeding method to present the reason for achieving lower gain; air (lossy-free) and epoxy FR-4 (ε
r
= 4. 4). The simulation results of both feeding methods are in line with the measurement results.