Polarization Reconfigurable Omnidirectional Antennas

RongLin Li and Yi Fan

School of Electronic and Information Engineering South China University of Technology

Guangzhou 510641, China lirl@scut.edu.cn

Abstract - A ±45° slant polarization (SP) reconfigurable

omnidirectional antenna and a circular polarization (CP) reconfigurable omnidirectional antenna are proposed. 16 PIN diodes are employed for the ±45° SP reconfigurable omnidirectional antenna while 8 PIN diodes are used for the CP reconfigurable omnidirectional antenna. Simulation and experimental results are demonstrated.

Index Terms —Polarization reconfigurable antenna, omnidirectional antenna.

1. Introduction

In recent years, a number of polarization reconfigurable antennas have been developed. But most of those are unidirectional antennas [1]–[4]. An omnidirectional circular polarization (CP) reconfigurable antenna is presented in [5] with 48 PIN diodes. In this paper, a ±45° slant polarization (SP) reconfigurable omnidirectional antenna with 16 PIN diodes and a CP reconfigurable omnidirectional antenna with 8 PIN diodes are proposed.

2. ±45° SP Reconfigurable Omnidirectional Antenna

The configuration of a ±45° SP reconfigurable omni-directional antenna is depicted in Fig. 1. The ±45° SP omnidirectional antenna consists of 4 crossed dipoles and a feeding network. 4 PIN diodes are introduced in each crossed dipole. When PIN diodes 1 and 3 are switched on and PIN diodes 2 and 4 switched off, +45° SP is obtained; otherwise −45° SP is implemented. A prototype, the S-parameter, and the radiation pattern of the ±45° SP reconfigurable omnidirectional antenna are shown in Figs. 2, 3, and 4, respectively.

Fig. 1. Configuration of the ±45° SP reconfigurable omnidirectional antenna.

Fig. 2. A prototype of the ±45° SP reconfigurable omnidirectional antenna.

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Simulated for +450 SP Simulated for -450 SP Measured for +450 SP Measured for -450 SP

1.79 GHz

Fig. 3. S-parameter of the ±45° SP reconfigurable omnidirectional antenna.

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Fig. 4. Radiation pattern of the ±45° SP reconfigurable omnidirectional antenna for+45° SP.

Proceedings of ISAP2016, Okinawa, Japan

Copyright ©2016 by IEICE

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3. CP Reconfigurable Omnidirectional Antenna

The configuration of a CP reconfigurable omnidirectional antenna is illustrated in Fig. 5. The CP omnidirectional antenna consists of 4 rectangular loops, a metallic cylinder, and a feeding network. 2 PIN diodes are inserted in each rectangular loop. When PIN diode 1 is switched on and PIN diodes 2 switched off, left-handed CP (LHCP) is achieved; otherwise right-handed CP (RHCP) is realized. A prototype, the S-parameter, axial ratio, and the radiation pattern of the CP reconfigurable omnidirectional antenna are demonstrated in Figs. 6, 7, 8, and 9, respectively.

Fig. 5. Configuration of the CP reconfigurable omnidirectional antenna.

Fig. 6. A prototype of the CP reconfigurable omnidirectional antenna.

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Simulated for LHCP Simulated for RHCP Measured for LHCP Measured for RHCP

2.4 GHz

Fig. 7. S-parameter of the CP reconfigurable omnidirectional antenna.

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al R

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Simulated for LHCP Simulated for RHCP Measured for LHCP Measured for RHCP

2.39 GHz

Fig. 8. Axial ratio of the CP reconfigurable omnidirectional antenna.

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Fig. 9. Radiation pattern of the CP reconfigurable omnidirectional antenna for LHCP.

4. Conclusion

A ±45° SP reconfigurable omnidirectional antenna and a CP reconfigurable omnidirectional antenna are developed. 16 PIN diodes are used for the ±45° SP reconfigurable antenna while 8 PIN diodes are employed for the CP reconfigurable antenna. These polarization reconfigurable omnidirectional antennas may find applications in polarization diversity for wireless communications.

Acknowledgment

The work is supported in part by the National Natural Science Foundation of China under Grant 61372009 and in part by the GDSTC under Grant 2014A010103011.

References [1] A. Khidre, K.-F. Lee, F. Yang, and A. Z. Elsherbeni, “Circular

polarization reconfigurable wideband E-shaped patch antenna for wireless applications,” IEEE Trans. Antennas Propag., vol. 61, no. 2, pp. 960-964, Feb. 2013.

[2] L.-H. Chang, W.-C. Lai, J.-C. Cheng, and C.-W. Hsue, “A symmetrical reconfigurable multipolarization circular patch antenna,” IEEE Antennas Wireless Propag. Lett., vol. 13, pp. 87-90, 2014.

[3] W. Lin and H. Wong, “Wideband circular polarization reconfigurable antenna,” IEEE Trans. Antennas Propag., vol. 63, no. 12, pp. 5938-5944, Dec. 2015.

[4] S. W. Lee and Y. J. Sung, “Simple polarization-reconfigurable antenna with T-shaped feed,” IEEE Antennas Wireless Propag. Lett., vol. 15, pp. 114-117, 2016.

[5] B. Li and Q. Xue, “Polarization-reconfigurable omnidirectional antenna combining dipole and loop radiators,” IEEE Antennas Wireless Propag. Lett., vol. 12, pp. 1102-1105, 2013.

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