A novel microstrip grid array antenna that is simultaneously high in gain and wide in bandwidth is proposed. To enhance its bandwidth, the antenna adopts elliptically shaped and variably dimensioned radiation elements as well as a linearly tapered ground plane, and is optimized by a parallel genetic algorithm (GA) on a cluster system. A prototype antenna was fabricated and tested. Results of simulation and measurement agree well and show the antenna exhibits encouraging properties, e.g., a maximum gain of approximately tely 15.1 dBi at 5.8 GHz; the |S11| ≤ 10 dB bandwidth and the 3dB gain-drop bandwidth are 25.6% (from 5.03 GHz to 6.51 GHz) and 27.6% (from 5.0 GHz to 6.6 GHz), respectively, of the center frequency, both of which are much wider than that of conventional microstrip grid array antennas. Moreover, the overlap between the antenna's impedance bandwidth and the gain bandwidth results in a wide effective operating frequency bandwidth of 25.6%, which is the largest so far achieved for microstrip grid-array antennas.
2. Conti, R., J. Toth, T. Dowling, and J. Weiss, "The wire grid microstrip antenna," IEEE Trans. on Antennas Propagat., Vol. 29, 157-166, 1981.
3. Nakano, H., I. Oshima, H. Mimaki, K. Hirose, and J. Yamauchi, "Center fed grid array antennas," IEEE AP-S Int. Symp., 2010-2013, 1995.
4. Nakano, H., T. Kawano, and J. Yamauchi, "A cross-mesh array antenna," 11th international Conference on Antennas and Propagation, 77-20, Apr. 2001.
5. Nakano, H., H. Osada, H. Mimaki, Y. Iitsuka, and J. Yamauchi, "A modified grid array antenna radiating a circularly polarized wave," IEEE 2007 International Symposium on Microwave, Antenna, Propagation, and EMC Technologies for Wireless Communications, 527-530, Aug. 2007.
6. Nakano, H., T. Kawano, and J. Yamauchi, "Meander-line grid-array antenna," IEE Proc. - Microw Antennas Propag., Vol. 145, No. 4, Aug. 1998.
7. Nakano, H., H. Osada, and J. Yamauchi, "Strip-type grid array antenna with a two-layer rear-space structure," 7th ISAPE, 58-61, Guilin, China, Oct. 2006.
8. Kawano, T. and H. Nakano, "A grid array antenna with C-figured elements," Electronics and Communications in Japan, Part 1, Vol. 82, No. 1, 58-68, 2002.
9. Nakano, H., T. Kawano, H. Mimaki, and J. Yamauchi, "Analysis of a printed grid array antenna by a fast mom calculation technique," 11th International Conference on Antennas and Propagation, Apr. 17-20, 2001.
10. Nakano, H., I. Oshima, H. Mimaki, K. Hirose, and J. Yamauchi, "Numerical analysis of a grid array antenna," Proc. of ICCS'94, 700-704, Singapore, 1994.
11. Nakano, H., T. Kawano, Y. Kozono, and J. Yamauchi, "A fast MoM calculation technique using sinusoidal basis and testing functions for a wire on a dielectric substrate and its application to meander loop and grid array antennas," IEEE Trans. on Antennas Propagat., Vol. 53, No. 10, 3300-3307, Oct. 2005.
12. Sun, M., Y. P. Zhang, Y. X. Guo, K. M. Chua, and L. L. Wai, "Integration of grid array antenna in chip package for highly integrated 60-GHz radios," IEEE Antennas and Wireless Propag. Lett., Vol. 8, 1364-1366, 2009.
13. Chen, X., K. Chen, and K. Huang, "A microstrip grid array antenna optimized by a parallel genetic algorithm," Microwave and Optical Technology Letters, Vol. 50, No. 11, 2976-2978, Nov. 2008.
14. Chen, X., G. Wang, and K. Huang, "A novel wideband and compact microstrip grid array antenna," IEEE Trans. on Antennas Propagat., Vol. 58, No. 2, 596-599, Feb. 2010.
15. Thors, B., H. Steyskal, and H. Holter, "Broad-band fragmented aperture phased array element design using genetic algorithms," IEEE Trans. on Antennas Propagat., Vol. 53, No. 10, 3280-3287, Oct. 2005.
16. Zhu, X., W. Shao, J.-L. Li, and Y.-L. Dong, "Design and optimization of low RCS patch antennas based on a genetic algorithm," Progress In Electromagnetics Research, Vol. 122, 327-339, 2012.
17. Jain, R. and G. S. Mani, "Dynamic thinning of antenna array using genetic algorithm," Progress In Electromagnetics Research B, Vol. 32, 1-20, 2011.