A 1-bit Low-Profile Millimeter-Wave Antenna Array With Electronically Controlled 2-D Wide-Angle Beam Scanning

A low-cost, low-profile, electronically controlled millimeter-wave antenna array with two-dimensional wide-angle beam scanning capability is presented. It consists of a planar waveguiding structure and a 1-bit transmitting surface. The waveguiding structure, which is composed of a power divider and a coupling cavity array, provides equal-amplitude in-phase energy output. And a receive-transmit element loaded with diodes is utilized to achieve 1-bit phase switching. More importantly, theoretical analysis and simulated results demonstrate that the parasitic beams of a 1-bit phased array can be eliminated by incorporating specific phase delays. Moreover, the sidelobe level is effectively reduced by optimizing these delays using the Particle Swarm Optimization algorithm. In this design, substrate-integrated coaxial lines are integrated into the 1-bit element to implement specific phase delays. The effectiveness of this method has been thoroughly verified through both simulated and measured results. The final 16×16 antenna array successfully eliminates parasitic beams over the band from 25.5 to 28.5 GHz, and achieves a peak gain of 21.12dBi at 26.5 GHz. The design achieves a scanning range exceeding ±58° at 26.5 GHz in the φ = 0°, φ = 45°, and φ = 90° planes. Compared to existing digitally quantized antennas, this design enables 1-bit two-dimensional wide-angle beam scanning in the millimeter-wave band based on a planar antenna structure, demonstrating strong potential for millimeter-wave applications.