Millimeter-Wave Multi-Beam SIW Antenna Array with Wide Beam Coverage

The multi-beam antennas which can generate multiple concurrent beams at the same-time frequency are expected to be applied in distributed multi-user mobile communication with improved space and spectrum utilization. While the current researches usually suffer from narrow-angle scanning. To solve this problem, in this paper, a 28 GHz multi-beam antenna array fed by a 4 × 4 Hadamard matrix beamforming network (BFN) is proposed. The compact BFN is designed and fabricated in a double-layer structure using SIW technology. By exciting different input ports, one single-beam and three dual-beam radiation patterns can be generated. The total seven beams point at -76°, -39°, -20°, 0°, 17°, 34°, and 54°. A good agreement can be observed between the simulated and measured results.