Broadcast beam synthesis in an 8T8R array in TDLTE and Sub-6GHz 5G band

Beamforming is an inseparable part of the technologies used in 5G base station antennas due to the increased wireless data traffic and mobile users. Among commonly generated beam types, the broadcast beam is one of the main beam types of today’s base station antennas. This paper presents a simple method to synthesize and generate 65° broadcast beam in different frequencies from 2.3 to 3.8 GHz. The proposed method has been implemented on an antenna array of four ±45 polarized crossed-dipoles, and the resulting beams are in accordance with the corresponding theory. The results show that one can design a 4-column array with various typical beamwidth values ranging from 50 to 90 degrees, including 65 degrees, which is the paper’s target. The limitation enforced by lateral element distance and their element pattern is studied as well. In some frequencies, 65° patterns were not achieved using the procedure of the presented method due to the effect of element distances and the element beamwidth, which is discussed in the paper. To solve this problem, the method of using asymmetrical weighting is examined successfully, obtaining higher achievable beamwidths.