Designing Of Log Periodic Dipole Antenna (Lpda) And It’s Performance Analysis

Abstract

The introduction of broadband communication system and radar technologies has demanded the design of broadband antennas. One of the major drawbacks with many RF antennas is that they have a relatively small bandwidth. The log periodic antenna is able to provide directivity and gain while being able to operate over a wide bandwidth. The log periodic antenna is used in a number of applications where a wide bandwidth is required along with directivity and a modest level of gain. It is sometimes used on the HF portion of the spectrum where operation is required on a number of frequencies to enable communication to be maintained. It is also used at VHF and UHF for a variety of applications, including some uses as a television antenna. The length and spacing of the elements of a log-periodic antenna increase logarithmically from one end to the other. Data transmission at higher rates requires wider bandwidths for the elements constituting a communication link. This required wideband antennas to be designed and used. In this thesis, a high gain(around 9dbi) Log Periodic Dipole Antenna of frequency range 1350MHz-2690MHz is designed in order to replace the existing low gain (around 6dbi) corner reflector conical antenna. High Frequency Structure Simulator (HFSS) software is used in the analysis process of the designed LPDA parameters. The design is made in such a way that it can cover maximum area within its frequency range. A physical antenna is also constructed though not tested in the field.