Connected spiral antennas for wideband circularly polarized antenna array, experimental investigations

A cavity backed array of 5 connected spiral antennas is presented. The circular polarization is generated using mono polarized spirals in an alternating configuration RHCP and LHCP. Due to the connection between spirals, the currents in the arms of one spiral flow into the arms of the adjacent spirals. The currents transmitted to the opposite polarized neighboring spiral radiate the same polarization. The proposed antenna array allows more than 500MHz bandwidth while being dual polarized and steerable +/- 30deg. The performance of the constructed array is presented and validated using electromagnetic simulations and radiation pattern measurements.