Grating Lobe Mitigation in Linear Phased Array Antennas Using Leaky-Mode of Bed of Nails

Cost reduction of high gain phased array antenna is achieved by reducing the number of elements and increasing the separation distance between them. However, grating lobes appear due to this large separation distance. Therefore, we present in this work a method to mitigate the grating lobe issue in uniform linear array antennas by using the bed of nails (BON) structure. Unlike the conventional implementation of the BON, in this work we implement it in its leaky-mode rather than the band gap mode. This results in increasing the radiation aperture and the directivity of the antenna array's unit cell and reducing the radiation gain toward the grating lobe direction. The simulation and measurement results of the antenna array with BON structure show 10 dB reduction of the grating lobes while enhancing the main beam gain by more than 1dB at the designed frequency.