Design of Aperture-Coupled Vivaldi-Antenna Array With Scan-Range-Improving Parasitic Resonators for Ka-Band

We present a linear Vivaldi-antenna array with a misalignment-robust nongalvanic transition and scan-range-improving parasitic resonators for 5G FR2-1 base-station applications. The array covers most of the Ka-band (26.5–40 GHz) on a scan range of $\pm 60 {\mathrm {^{\circ}}}$ with a total active reflection coefficient of below −10 dB and a scan gain of above 10 dBi. Furthermore, the parasitic resonators increase the scan range to $\pm 85 {\mathrm {^{\circ}}}$ between 30 and 35 GHz. A prototype of the array is measured and the performance is confirmed to coincide well with the simulations.