Design of a composite dipole antenna array with direct feed is presented. In the form of printed-circuit antennas, the structure of the design consists of a doublet antenna and an elliptic loaded monopole antenna with a skirted dipole. As the load of the antenna array, this elliptic monopole provides wider bandwidth. Therefore, with the load possessing a radiation characteristic, it contributes to enhancing efficiency of the antenna array and hence the omni-directional radiation gain. A good agreement between simulated results by CST Microwave Studio® and tested results suggests that the reflection coefficient for the frequency range between 4.35 GHz to 5.0 GHz is lower than -10 dB. The out-of-roundness on H-plane is lower than 2dB and the maximum gain is higher than 6dB for the frequency range from 4.6 to 5.0 GHz. What's more, the gain per wavelength is about 4 dB, showing the antenna's excellence in miniaturization.
2. Lin, S., et al., "The simulation research of a novel UWB triangle monopole antenna," International Conference on Antenna Theory and Techniques, 256-258, Sept. 17-21, 2007.
3. Lizzi, L., G. Oliveri, P. Rocca, and A. Massa, "Planar monopole UWB antenna with UNII1/UNII2 wlan-band notched characteristics," Progress In Electromagnetics Research B, Vol. 25, 277-292, 2010.
4. Chayono, R., M. Haneishi, and Y. Kimura, "Inverted triangle printed monopole antenna with halfdisk for UWB applications," Proceedings of Asia-Pacific Microwave Conference, 1994-1997, Dec. 12-15, 2006.
5. Thanormsuay, S., P. Thosdee and C. Thongsopa, "Array of quasi-rhomboid antenna for ultra wideband applications," Proceedings of ECTI-CON, 293-296, 2008.
6. Ren, Y.-J., et al., "Compact ultrawideband UHF array antenna for through-wall radar applications," IEEE Antennas and Wireless Propagation Letters, Vol. 8, 1302-1305, 2009.
7. Zuo, S. L., Y. Z. Yin, Z. Y. Zhang, and X. Yang, "A design method to acquire high gain for omni-direction radiation applied in WiMAX," Wireless Communications Networking and Mobile Computing, 1-4, Sept. 24-26, 2009.
8. Zhang, Z. Y., G. Fu, S. X. Gong, S. L. Zuo, and T. Ran, "Printed 6-element dipole array antenna for omnidirection applied in WiMAX," Wireless Communications Networking and Mobile Computing (WiCOM), 1-4, Sept. 23-25, 2010.
9. Chen, X., K. Huang, and X.-B. Xu, "A novel planar slot array antenna with omnidirectional pattern," IEEE Transactions on Antennas and Propagation, Vol. 59, No. 12, 4853-4857, Dec. 2011.