1. [1] T. Imai, K. Kitao, N. Tran, N. Omaki, Y. Okumura, M. Sasaki, and W. Yamada, “Development of high frequency band over 6GHz for 5G mobile communication systems,” Proc. 2015 IEEE 9th European Conference on Antennas and Propagation (EuCAP), Lisbon, Portugal, April 2015.
2. [2] G. Liang, W. Gong, B. Jia, H. Liu, and J. Yu, “Demonstration of a digital beamforming transmitter array with 16 beams,” Proc. IEEE International Conference on Computational Problem-Solving, Lijiang, China, Dec. 2010.
3. [3] T. Umezawa, P.T. Dat, K. Kashima, A. Kanno, N. Yamamoto, and T. Kawanishi, “100-GHz radio and power over fiber transmission through multicore fiber using optical-to-radio converter,” IEEE J. Lightwave Technol., vol.36, no.2, pp.617-623, Jan. 2018. 10.1109/jlt.2017.2731991
4. [4] T. Nagayama, S. Akiba, T. Tomura, and J. Hirokawa, “Photonics-based millimeter-wave band remote beamforming of array-antenna integrated with photodiode using variable optical delay line and attenuator,” IEEE J. Lightwave Technol., vol.36, no.19, pp.4416-4422, March 2018. 10.1109/jlt.2018.2821185
5. [5] M.S. Alavi, R.B. Staszewski, L.C.N. de Vreede, A. Visweswaran, and J.R. Long, “All-digital RF I/Q modulator,” IEEE Trans. Microw. Theory Techn., vol.60, no.11, pp.3513-2526, 2012. 10.1109/tmtt.2012.2211612