Acknowledgements

phase distribution of the waveforms at the outputs of the OBM, previously obtained

39.0 10.4 9.5 9.1 8.3 7 6.1 5.6 4.8 38.0 0 0 0.5 0.5 0 0 0.4 0.5 40.5 13.2 12.7 11 9.8 9.2 8 6.5 5.2

B1 B5 B2 B6 B3 B7 B4 B8

• According to Table 6, the phase error values for the tested delay elements of

• According to Table 7, the phase error values for 88 PIC-based OBM under

• According to Figure 17, the replacement of phase shifters with TTD elements led to a change in the position of the main lobe maximum and an increase in the relative level of side lobes. However, in comparison with the ideal radiation patterns of Figures 9–11, the azimuth position change does not exceed 2°,

In the chapter, we explored and demonstrated the effectiveness of using reconfigurable multiple-beam array feed network based on millimeter-wave integrated photonics beamformers for the phased array antennas, which were known for a long time in the radar technique, in the small cells of the incoming fifthgeneration mobile communication systems. The study was carried out using a specific example of designing an 88 optical Butler matrix-based photonics-steered beamforming network of a transmitting phased array antenna for a pico-cell remote station operating in the Ka/V-band with a 16% fractional bandwidth allocated as a promising one for future 5G systems. For this goal, we firstly reviewed the specialties of millimeter-wave photonics technique in 5G wireless networks of Radio-over-Fiber architecture. Then, to determine the input data for subsequent design, a theoretical background of array antenna beam steering using ideal models of phase shifters and true-time delay lines was presented. Comparison of the two most frequently used approaches to the design of multiple-beam antenna arrays based on Butler or Blass matrices showed the advantage of the first option for operation in

A brief analysis of the available integrated millimeter-wave optical beamforming

networks showed that the direction is at the initial stage of its development. A distinctive feature of the optical Butler matrix for designing beamformers is the

, which is approximately 50 times less than the size of the electronic

• The assessment showed that the approximate area of the PIC is near

using the calculation in the VPI software.

Advances in Array Optimization

PIC-based OBM are not more than 4°.

test are not more than +10°/13°.

270 mm2

Table 7.

6. Conclusion

128

counterpart [36].

the remote station of a 5G pico-cell.

The following outputs can be derived from our study:

The phase error values for the center and two extreme frequencies of the RF generators.

Input RF (GHz) Output

and the increase in the level is not more than 2 dB.

This work was supported by the Russian Foundation for Basic Research, Grants No. 17-57-10002 and No. 18-29-20083.
