LAUSR

A wideband $8 \times 8$ element slot antenna array based on ridge gap waveguide feeding network has been proposed for mmWave applications. The antenna subarray consists of four radiating slots which are excited by a groove gap cavity layer. Compared with previously published works, the proposed planar antenna array has quite wide impedance bandwidth. The antenna covers a wideband of 50–67.8 GHz with 30% impedance bandwidth (VSWR < 2). Also, the antenna has only 2.5 dB gain variation over the entire bandwidth which implies also good radiation characteristics for the proposed antenna. The maximum measured gain value is about 27.5 dBi with a total efficiency of 80% for the proposed antenna within the band of interest. With this performance, the proposed antenna array is a promising candidate for mmWave communication systems.