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.