Comparison of phased array configurations of spiral antennas

A wideband spiral antenna array configuration with interstitially packed spiral antennas is presented. It is compared with a spiral array in the linear and the Wideband Array of Variable Elements Sizes (WAVES) configuration. All three configurations are realized, measured and compared. By packing smaller spiral elements in the interstices of a linear spiral array, we observe an improvement of more than 14 dB in grating lobe rejection compared to the traditional linear configuration when the main beam is pointing at boresight.