The influence of feed tube changes on performance of log periodic dipole antenna

Abstract

Changes in feed tube spacing and the location of feed point will affect the performance of Log Periodic Dipole Antenna (LPDA). In this paper, two log periodic dipole antennas, one works in a higher frequency band and another works in a lower frequency band, will change their own Voltage Standing Wave Ratio (VSWR) with the changes in feed tube spacing and the location of feed point. Based on plenty of frequency sweep in HFSS software and data analysis, this paper gives a method on how to change the feed tube to get the best VSWR.