Dual-circular polarized planar array of connected sinuous antennas

Self-complementary four-arm sinuous antennas are used to realize a uniform planar array with dual-polarization capability. Connections between adjacent antenna elements are examined to extend the bandwidth in the lower operating region. A nine-element uniform planar array is modelled with CST Microwave Studio and the effects of the connections are presented. The improvements in the active reflection coefficient and the realized gain of the antenna are reported together with the feeding techniques used for both circular polarizations. The connections improve the reflection coefficient at high frequencies to achieve the performance predicted by theory. And at lower frequencies, a new band is added.