۱٫ Introduction

۲٫ Implementation Methods

۳٫ Conclusion

۴٫ Acknowledgement

۵٫ References

In practical, it is a challenge to design an antenna with circular polarization and omnidirectional patterns simultaneously. For convenient design, four detail methods for circularly polarization omnidirectional antenna are summarized and analyzed referencing the reported theses and papers. The summarized method can provide a direct guideline for researchers and engineers, which is useful for design efficiency improvement.

Introduction

Omnidirectional antennas, which radiate isotropic energy in a specific plane, have been widely used in the fields of digital television, point-to-point communication system and wireless communication [1]. Circularly polarized omnidirectional antennas not only have omnidirectional patterns, but also radiate circularly polarized wave. These two properties have great potential in the wireless communication, radar systems, exploration remote sensing electronic reconnaissance and electronic interference [2]. In space communication systems, remote systems and celestial equipment system, the circularly polarized omnidirectional antennas are core devices to decrease signal loss. Also, it can eliminate the polarized distortion caused by Faraday rotation effect in the ionosphere efficiently. In electronic reconnaissance field, the circularly polarized omnidirectional antennas can detect and disturb all electromagnetic wave but pure anti-directional circularly polarization wave.