Performance comparison of two types of low-profile sinuous antenna in ultra wideband application

The objective of this work is comparing two types of sinuous antenna in equal size and geometrical parameters already reported in [1]-[2]. The performance of these antennas was investigated over a wide frequency range by comparison between simulation results in a similar size 5.3 cm×5.3 cm. The return loss of the optimized Duhamel´s sinuous antenna exhibit an ultra-wideband (UWB) performance better than 10 dB from 2.5 to 13 GHz with input impedance of 220 Ω. In Vahdani´s sinuous antenna, a return loss better than 10dB from 3.3 to 10.45 GHz with input impedance of 150 Ω was obtained. Other parameters which were investigated in this study are gain, directivity and HPBW.