An Orbital Angular Momentum (OAM) Mode Reconfigurable Antenna for Channel Capacity Improvement and Digital Data Encoding

Baiyang Liu,Yuehui Cui,Ronglin Li,Guoying Lin

doi:10.1038/s41598-017-10364-4

Baiyang Liu, Yuehui Cui + Show 2 more

Open Access

https://doi.org/10.1038/s41598-017-10364-4

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Journal: Scientific Reports	Publication Date: Aug 29, 2017
Citations: 34	License type: open-access

Affiliation: South China University of Technology

Abstract

For purpose of utilizing orbital angular momentum (OAM) mode diversity, multiple OAM beams should be generated preferably by a single antenna. In this paper, an OAM mode reconfigurable antenna is proposed. Different from the existed OAM antennas with multiple ports for multiple OAM modes transmitting, the proposed antenna with only a single port, but it can be used to transmit mode 1 or mode −1 OAM beams arbitrary by controlling the PIN diodes on the feeding network through a programmable microcontroller which control by a remote controller. Simulation and measurement results such as return loss, near-field and far-field radiation patterns of two operating states for mode 1 and mode −1, and OAM mode orthogonality are given. The proposed antenna can serve as a candidate for utilizing OAM diversity, namely phase diversity to increase channel capacity at 2.4 GHz. Moreover, an OAM-mode based encoding method is experimentally carried out by the proposed OAM mode reconfigurable antenna, the digital data are encoded and decoded by different OAM modes. At the transmitter, the proposed OAM mode reconfigurable antenna is used to encode the digital data, data symbol 0 and 1 are mapped to OAM mode 1 and mode −1, respectively. At the receiver, the data symbols are decoded by phase gradient method.

Highlights

With the development of multifunction requirements in wireless communication systems, reconfigurable antennas are required to fulfill these demands[9,10,11]
We design a four-elements Uniform circular array (UCA) with reconfigurable feeding network to provide two kinds of phase shifting for mode 1 and mode −1 orbital angular momentum (OAM) beams generation
Combining the concept of OAM mode multiplexing for channel capacity improvement with reconfigurable antenna, an OAM mode reconfigurable antenna is firstly proposed in this paper

Summary

Introduction

With the development of multifunction requirements in wireless communication systems, reconfigurable antennas are required to fulfill these demands[9,10,11]. By controlling the PIN diodes, polarization-reconfigurable antenna can be used to mitigate the polarization mismatch between the receiver and transmitter[16,17,18]. An OAM mode reconfigurable antenna is proposed, which can be used to transmit or receive mode 1 or mode −1 OAM beams by controlling the PIN diodes. The OAM mode reconfigurable antenna is simulated, fabricated and measured. It will be demonstrated by measurement that the proposed antenna can get a maximum 18 dB OAM diversity gain in near-field zone LOS link at 2.4 GHz. we use the proposed antenna as transmitter to encode the digital data, mode 1 OAM beam representing symbol 0 and mode −1 OAM beam representing symbol 1. Experimental result shows that the proposed antenna is a good candidate for OAM based encoding

Methods

Results

Conclusion