Novel planar complex spiral ultra-wideband antenna

Planar equiangular spiral antenna and Archimedean spiral antenna are two kinds of ultra-wideband circular polarized antennas, which are used in various applications. However, the lower frequencies of these antennas are limited by their dimensions. In order to minimize antenna´s dimension, we designed an equiangular spiral-Archimedean spiral-integrated antenna. In the frequency spectra 400 MHz-2000 MHz, the measured return loss of the proposed UWB antenna is less than -10dB. This novel antenna´s wide band characteristic, especially the characteristic in the lower frequency, is better than that of the planar equiangular spiral antenna in the same dimension.