Dual-Flattop-Beam Antenna Array Utilizing Grating Lobes

A dual-flattop-beam antenna array exploiting grating lobes is proposed in this article. By control the spacing of the array factor, the grating lobes with expected point angles are designed. Then, an antenna element composed by two patches is utilized to radiate dual-beam. The pointing angles of the grating lobes are designed to be consistent with that of the element. In this way, the realized gain of the dual-beam is accumulated. Moreover, in order to enlarge the beam coverage, the dual-flattop-beam is implemented by optimizing the excitation phases and amplitudes of the elements. Finally, a 8-element array is presented. The simulation results show that the total 3 dB beam coverage is from -69.3° to -25.5° and +25.3° to +69.4°, and the maximum realized gain is 7.74 dBi. Compared with the traditional array, the proposed array has a wide radiation range, low sidelobe level, small gain ripple and few radiating elements.