16-element Vivaldi antenna array fed by a single ridge substrate integrated waveguide with over 75% bandwidth

A 16-element Vivaldi antenna array with a single ridge SIW feed network has been developed using a two-layer substrate. The single ridge substrate integrated waveguide (RSIW) structure is used to sustain the inherent wide bandwidth performance of the Vivaldi array. The array itself is fed by a novel compact and wide band RSIW eight way divider that is excited by a wideband GCPW to RSIW transition. Vivaldi elements are arranged in an elegant way to avoid wide spacing between the array elements to avoid grating lobes, which is typical for waveguide fed antenna arrays with large apertures. The 16-element uniform linear array was fabricated and its measured 10-dB bandwidth exceeded 75% with a 12-16 dB and 75% efficiency gain and efficiency respectively, over 6 to 11 GHz. Measured results are consistent with simulated ones.