A wide beam, circularly polarized (CP) antenna is presented for satellite communications. The antenna consists of two crossed bent dipoles, two baluns and two pairs of rectangular patches. The two dipoles are fed by the two baluns, respectively. The arms of the dipoles are bent to save the horizontal space and to broaden the beamwidth. The rectangular patches which are connected to the arms of the dipoles form the matching structure of the proposed antenna. The impedance bandwidth of the antenna is broadened by adjusting the length of the rectangular patches. A broadband 90° power divider is used to feed the proposed antenna and to realize circular polarization. The antenna has a -10-dB impedance bandwidths of 77% (1.73-3.89 GHz). The proposed antenna exhibits a measured 2-dB AR bandwidth of 76.3%, from 1.71 GHz to 3.8 GHz. The 3-dB beamwidth is greater than 88°over the whole working band. Results show that the proposed antenna is suitable for the application of satellite communications.
2. Luo, Y., Q.-X. Chu, and L. Zhu, "A miniaturized wide-beamwidth circularly polarized planar antenna via two pairs of folded dipoles in a square contour," IEEE Trans. Antennas Propag., Vol. 63, No. 8, 3753-3759, Aug. 2015.
3. Zhou, Y. J., C. C. Chen, and J. L. Volakis, "Single-fed circularly polarized antenna element with reduced coupling for GPS arrays," IEEE Trans. Antennas Propag., Vol. 56, No. 5, 1469-1472, May 2008.
4. Heidari, A. A., M. Heyrani, and M. Nakhkash, "A dual-band circularly polarized stub loaded microstrip patch antenna for GPS applications," Progress In Electromagnetics Research, Vol. 92, 195-208, 2009.
5. Yang, S. L. S., K. F. Lee, and A. A. Kishk, "Design and study of wideband single feed circularly polarized microstrip antennas," Progress In Electromagnetics Research, Vol. 80, 45-61, 2008.
6. Lin, Y.-F., H.-M. Chen, F.-H. Chu, and S.-C. Pan, "Bidirectional radiated circularly polarised square-ring antenna for portable RFID reader," Electron. Lett., Vol. 44, No. 24, 1383-1384, Nov. 2008.
7. Mak, K. M. and K. M. Luk, "A circularly polarized antenna with wide axial ratio beamwidth," IEEE Trans. on Antennas Propagat., Vol. 57, No. 10, 3309-3312, Oct. 2009.
8. Choi, E.-C., J. W. Lee, and T.-K. Lee, "An axial ratio beamwidth enhancement of S-band satellite antenna with parasitic elements and its arrays," IEEE Antennas Wireless Propag. Lett., Vol. 13, 1689-1692, 2014.
9. Li, M. and K.-M. Luk, "Wideband Magnetoelectric Dipole antennas with dual polarization and circular polarization," IEEE Antennas and Propagation Magazine, Vol. 57, No. 1, Feb. 2015.