VERTICAL AND HORIZONTAL SECTORIZATION

Vertical sectorization doubles the number of horizontally sectorized beams (see Figure 7),⁸ which can be used to vertically split the inner and outer cells, improving system performance as shown in Figure 7a. It is also useful for users at high elevations (see Figure 7b). In dual parabolic cylindrical reflectors, simultaneous vertical and horizontal sectorization can be achieved by using two, three or more rows of feeds at the same time (see Figure 1a), which adds more freedom and flexibility to generate multiple beams in different forms and configurations.^9,10 The number of rows in the feed array determines the number of vertical sectorized sets of beams, while the number of feeds in each row determines the number of beams (subsectors) in each of the sets. The feed array shown in Figure 1a generates three vertically sectorized sets of beams, where each set contains five beams (subsectors).

Figure 7 Simultaneous vertical and horizontal sectorization can vertically split the inner and outer cells (a) and reach users at high elevations (b).

For example, Figure 8 shows the radiation patterns of two sets of penta-beams in two vertically sectorized groups using two rows of feeds. The horizontal feed locations in the two rows are adjusted so the peaks of the upper set of beams are above the nulls of the lower set of beams and vice versa. Hence, every user is close to the peak of one of the beams. The azimuth is covered by 40 beams with 80 ports (±45 degree polarization). Alternatively, three feed rows can be used together with the penta-beam configuration to cover the azimuth plane by 60 beams with 120 ports (see Figure 9).

Figure 8 Azimuth (a) and elevation (b) patterns of four penta-units covering 360 degrees with 40 beams.

Figure 9 Azimuth (a) and elevation (b) patterns of four penta-units covering 360 degrees with 60 beams.

The sub-6 GHz penta-beam base station antenna can be used to generate different forms of vertical sectorization at the same time as the horizontal sectorization. For example, in Figure 9b, two sets of the horizontally sectorized penta-beams are tilted down by different tilt angles, while the third is not tilted. Instead, three vertically sectorized sets of the penta-beams can be generated with upward, zero and downward vertical beam tilt, as shown in Figure 10a. Any of these forms of vertical sectorization can be produced according to the application, and all the planned vertically sectorized sets may be produced and used together. Alternatively, only some of these planned sets may be generated and used, as shown in Figure 10b.

Figure 10 Vertical sectorization with upward and downward tilting using three (a) and two (b) vertically sectorized sets.

Different numbers and forms of vertically sectorized sets with different vertical tilt angles can be generated in different horizontal main sectors; the horizontal main sectors do not have to use similar configurations as the vertically sectorized sets. All of this can be achieved and modified at any time without replacing the antenna. Only the locations of the feeds are changed.

Note that tilting the beams up and down in vertical sectorization depends on the requirements of the application. For example, tilting the beams down can be used to serve vertically split inner and outer cells, as shown in Figure 7a, while tilting the beams up is very useful when targeting users located on top floors of a high-rise building, serving them with a dedicated beam or vertical sector (see Figure 7b).

CONCLUSION

This article has described a foldable and deployable 5G sub-6 GHz (3.3 to 7.0 GHz) switched-beam smart base station antenna using no active components, comprising dual parabolic cylindrical reflectors with multiple resonant feeds that supports simultaneous horizontal and vertical sectorization. The peaks of the upper elevation beams can be adjusted to be above the nulls of the lower beams and vice versa, so every user is close to the peak of one of the beams. The entire azimuth plane is divided into three or four (i.e., 120 or 90 degree) main sectors, enabling a switched-beam smart base station antenna covering the entire 360 degree plane. Each main sector unit can generate three, four, five or more beams (subsectors), and the antenna can generate an arbitrary number of beams ranging from nine to 60 beam to cover the azimuth plane with 18 to 120 ports (±45 degree polarization). RET with arbitrary vertical/horizontal tilting angles can be separately applied to each beam. The number of generated beams, their configurations and the tilt angle of each beam can be changed by modifying the number of feeds and their locations, without replacing the antenna.

ACKNOWLEDGMENT

The authors would like to thank Ibrahim Abdelgaied for his great effort preparing this paper. This research was fully financed by and assigned to Amant Antennas (www.amantantennas.com).

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