Design and Development Trends of Millimeter-Wave Multi-Beam Antennas

Millimeter-wave (mmWave) multi-beam antennas are integral to next-generation wireless communication systems, facilitating high-speed and high-capacity communication, and ensuring extensive coverage. Multi-beam antennas exploit fundamental principles such as beamforming, beam separation, frequency reuse, and interference mitigation, enabling a single aperture to generate multiple independently directed beams. And these antennas can be broadly classified into passive, active, and hybrid types based on their implementation, each providing distinct characteristics tailored to specific applications. Therefore, this paper reviews the research on multi-beam antennas over the past decade, summarizing their key features and applications, and predicting future development trends in mmWave multi-beam antennas. The results demonstrate that as mmWave technology continues to be increasingly adopted in communications, future multi-beam antennas will prioritize dynamic adaptability, system autonomy, and the reduction of structural complexity and cost, enhancing support for high-speed, low-latency, as well as high-capacity intelligent communication systems. This evolution will be critical for meeting the demands of emerging applications, including 5G/6G networks, IoT, and autonomous systems.