A Multifrequency Reflector Base Station Antenna With Enhanced Beam-Scanning Capabilities for 6G

This letter presents a multi-frequency base station antenna with enhanced beam scanning capabilities for high data rate 6 G communication. The antenna consists of a dual-polarized multi-frequency feed and a novel dual-cylindrical reflector antenna (DCRA). Through the rotation of the sub-reflector, which is illuminated by the feed, the beam can be scanned across a wide angle along the planar cylindrical orientation of the main reflector. This scanning process results in a beam scanning angle that is roughly twice the rotation angle of the sub-reflector. The phase center of the reflected beam from the sub-reflector is designed to coincide with the focal line of the main reflector, enabling two-dimensional focusing of the beam without loss of the scanning angle. A concise design formula based on the described antenna structure is derived, enabling the entire antenna design to follow a clear design flowchart, which incorporates a rapid method for determining the focal length product and focal point locations using near-field Fast Fourier Transform (FFT). The designed antenna achieves <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\pm 20^{\circ }$</tex-math></inline-formula> beam scanning coverage at 45 GHz, 100 GHz, and 220 GHz, with a gain exceeding 50 dBi at 220 GHz. Both simulation and experimental results validate the effectiveness of the proposed method.