Rotman Lens-Fed Antenna for Generating Multiple Orbital Angular Momentum (OAM) Modes With Gain Enhancement

Dan Wu,Xiaowei Shi,Guang Fu,Xi Li,Lin Yang,Zhiya Zhang

doi:10.1109/access.2020.2971563

Dan Wu, Xiaowei Shi + Show 4 more

Open Access

https://doi.org/10.1109/access.2020.2971563

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Abstract

A compact multi-layer Rotman lens-fed array antenna which can generate nine orbital angular momentum (OAM) modes is presented in this paper. The proposed antenna consists of a microstrip Rotman lens and a nine-element circular array antenna which utilizes high-gain patch element in order to enhance the gain of OAM beam. A stacked patch loaded with two slots is attached above the patch element to effectively enhance the antenna gains. By employing the Rotman lens as the feed network of the circular array, nine OAM-carrying beams of modes number $\ell =0$ , ±1, ±2, ±3 and ±4 can be produced when different input ports are excited, respectively. 160°-phase-shift on adjacent output ports can be achieved to meet the phase requirement of OAM modes of $\ell =\pm 4$ . Moreover, the Rotman lens is modified by adjusting the deflection angle of the beam ports and array ports so as to achieve uniform amplitude distribution on the output ports. Hence, the pattern characteristics of OAM beams can be effectively improved by making all the output ports are equal in amplitude. The C-band prototype of the antenna is fabricated and measured. Both the simulation and measurement results indicate that nine OAM modes can be generated by using the proposed structure. The proposed antenna can be used in an OAM-based wireless communication system.

Highlights

The 1st version of the Fifth Generation New Radio standard (5G NR) has been completed by the Third Generation Partnership Project (3GPP) to meet the requirements set forth for IMT-2020 by the International Telecommunication Union (ITU), work on evolving wireless communication technologies is never stopped to fulfill the visions towards generation
orbital angular momentum (OAM) enables a new dimension for wireless data transmission and can be identified by the azimuthal phase distribution of exp(j φ), where represents OAM mode and φ is the azimuthal angle
This paper proposes an antenna design which utilizes a Rotman lens feeding a circular array to realize multiple OAM modes

Summary

Introduction

The 1st version of the Fifth Generation New Radio standard (5G NR) has been completed by the Third Generation Partnership Project (3GPP) to meet the requirements set forth for IMT-2020 by the International Telecommunication Union (ITU), work on evolving wireless communication technologies is never stopped to fulfill the visions towards generation. D. Wu et al.: Rotman Lens-Fed Antenna for Generating Multiple (OAM) Modes With Gain Enhancement high-efficiency planar reflect arrays in [9], traveling-wave ring-slot structure in [10] and metasurface in [11], [12]. The circular antenna array is used in this paper for the generation of multiple OAM modes.

Results

Conclusion