Effect of dielectric substrate on performance of planar trapezoidal toothed log-periodic antenna

In this paper performance of planar trapezoidal toothed log-periodic antenna on different dielectric substrates through simulation using FEM based Ansoft HFSS software has been presented. This antenna is a type of frequency independent antenna. The performance characteristics of the proposed antennas formed by providing definite conducting pattern characterizing the antenna on different substrate materials (Bakelite (ε_r = 4.8, tanδ = 0.002), FR4_epoxy (ε_r = 4.4, tanε = 0.02), Arlon25FR (ε_r =3.43, tanε = 0.0035) and Teflon (ε_r = 2.08, tanε = 0.001)) having thickness of 1.6 mm as well as metal antenna without substrate material are studied. It is observed from the study that antenna on Teflon substrate provides widest bandwidth among all the substrate antennas. Further, the performance of antenna on Teflon substrate is almost similar to metal antenna without substrate.