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

This research has been supported by the Ministry of Education, Youth and Sports of the Czech Republic under the project OP VVV Electrical Engineering Technologies with High-Level of Embedded Intelligence CZ.02.1.01/0.0/0.0/18_069/0009855 and by the project SGS- 2021-005: Research, development and implementation of modern electronic and information systems.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 (er = 4. 4). The simulation results of both feeding methods are in line with the measurement results