Connected Spiral Antennas for Wideband Circularly Polarized Antenna Array, Experimental Investigations
Abstract
A cavity backed dual polarized printed antenna array composed of connected planar spiral antennas is presented. This array is composed of 5 spiral antennas printed on a FR4 substrate where the dual 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. Therefore, the proposed antenna array allows up to 60% bandwidth while being dual polarized. The antenna array feeding system is described and the performances of the constructed array are presented and validated using electromagnetic simulations and radiation pattern measurements