A 2×2 waveguide-fed antenna array with more than 25% bandwidth in the Ku-band

This paper proposes a novel 2×2 waveguide-fed antenna array to achieve wide bandwidth performance in the Ku-band. Basically the antenna array consists of three portions: a feeding waveguide, a cavity and a radiating aperture, from bottom to top, respectively. All the portions are designed to match with each other in a wideband. Experimental results show that the antenna can achieve more than 25% operational bandwidth with VSWR less than 2.0. The first sidelobe levels are around -14 dB and the overall cross polarization levels are well suppressed less than -26 dB.