**Acknowledgements**

The authors would like to thank Dr. Zhihui Liu for her support in reviewing. This work is supported by Innovation Funds of China Aerospace Science and Technology (No. Y-Y-Y-GJGXKZ-18, No. Z-Y-Y-KJJGTX-17) and the 2017 Open Research Fund of Key Laboratory of Cognitive Radio and Information Processing, Ministry of Education, Guilin University of Electronic Technology (No. CRKL170202).

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**Author details**

Beijing, China

Tao Dong1,2\*, Yue Xu1,2 and Jingwen He1,2

provided the original work is properly cited.

1 State Key Laboratory of Space-Ground Integrated Information Technology,

© 2020 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium,

2 Beijing Institute of Satellite Information Engineering, Beijing, China

\*Address all correspondence to: dongtaoandy@163.com

*Plasmonic Nanoantenna Array Design*

*DOI: http://dx.doi.org/10.5772/intechopen.90782*

*Plasmonic Nanoantenna Array Design DOI: http://dx.doi.org/10.5772/intechopen.90782*

*Nanoplasmonics*

**4. Conclusion**

24.2 dB at 1550 nm.

great benefits to human life.

**Acknowledgements**

(No. CRKL170202).

In this chapter, we review the silicon-based optical nanoantennas and their applications in OPA for beam steering. In order to obtain an OPA with high gain and wide beam steering range, we propose a sub-wavelength plasmonic nanoantenna with an operating wavelength of 1550 nm. The proposed plasmonic nanoantenna consists of a silver block and a silicon block with a standard silicon waveguide for feeding light into the nanoantenna. On the basis of LSPR, the plasmonic nanoantenna radiates light vertically upward with a high gain of 8.45 dB at 1550 nm. There is a good impedance match between the plasmonic nanoantenna and the silicon waveguide in a frequency range from 176.7 to 248.5 THz. Furthermore, two nanoantenna arrays (1 × 8 and 8 × 8) with the element spacing of 0.7λ0 composed of the proposed plasmonic nanoantennas are designed, and their beam steering radiation patterns are studied in detail. The simulation results show that the 1 × 8 array can be used to realize 1-D beam steering from −44.0° to +44.0° with a gain of 14.5 dB at 1550 nm, and the 8 × 8 array can achieve a 2-D beam steering from −44.0° to +44.0° in one dimension and from −45.0° to +45.0° in the other dimension with a gain of

The plasmonic nanoantenna we proposed is a good candidate for the extension of the nanoantenna array used in a large-scale OPA. Utilizing the proposed plasmonic nanoantenna, a 3-D array extend mode can be adopted to form an OPA with thousands of optical nanoantennas. We first make a 1-D OPA as a sub-layer, in which the optical power division network, phase shifters, and a 1-D plasmonic nanoantenna array are integrated in a plane. After that, such 1-D OPA layers are extended longitudinally. Therefore, a highly integrated OPA containing thousands of optical nanoantennas with sub-wavelength element spacing can be obtained theoretically to steer beam in a wide angle without grating lobes. However, the processing of the OPA with multilayer structure is limited by our micro/nanofabrication technology. We believe that with the development of micro/nanoprocessing technology, the large-scale OPA will be applied in various fields of optical communication, LiDAR, security monitoring, and display advertising, which will bring

The authors would like to thank Dr. Zhihui Liu for her support in reviewing. This work is supported by Innovation Funds of China Aerospace Science and Technology (No. Y-Y-Y-GJGXKZ-18, No. Z-Y-Y-KJJGTX-17) and the 2017 Open Research Fund of Key Laboratory of Cognitive Radio and Information Processing, Ministry of Education, Guilin University of Electronic Technology

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