volume | PIER Journals

Abstract

A novel slot antenna that consists of an H-shaped slot encompassed by a rectangular metallic wall and a pair of C-shaped slots outside the wall is proposed. It features a unidirectional pattern, small electrical dimensions and medium gain. The H-shaped slot radiates as an inductively loaded magnetic dipole while the induced electric currents on the vertical wall radiates as electric dipoles. The front-to-back ratio (FBR) of the antenna can be controlled by proper constructive and destructive interferences of radiating fields of the magnetic and electric dipoles. The size of the ground plane can be reduced by the use of the C-shaped slots that confine the currents to the proximity of the metallic wall. Two prototype antennas operating at 2.4 GHz were designed. By adjusting the structure parameters, the front-to-back ratio of the antenna can be conveniently altered. The first prototype has an impedance bandwidth (BW) of 3.8% for SWR ≤ 2, a 4.6 dBi gain, a 10-dB FBR and a ground size of 0.84λ₀ × 0.64λ₀ where λ₀ is the free-space wavelength at the center frequency. The corresponding figures of the second prototype are 1.83%, 4.1 dBi, over 20 dB and 0.64λ₀ × 0.64λ₀. Both antennas have a height of 0.128λ₀.

1. Balanis, C. A., Antenna Theory: Analysis and Design, John Wiley & Sons, Inc., 2005.

2. Janaswamy, R. and D. H. Schaubert, "Analysis of the tapered slot antenna," IEEE Trans. Antennas Propagat., Vol. 53, 1058-1065, Sept. 1987.
doi:10.1109/TAP.1987.1144218

3. Yang, Y., Y. Wang, and A. E. Fathy, "Design of compact Vivaldi antenna arrays for UWB see through wall applications," Progress In Electromagnetics Research, Vol. 82, 401-418, 2008.

4. Zhang, X. C., J. G. Liang, and J. W. Xie, "The quasi-Yagi antenna subarray fed by an orthogonal T junction," Progress In Electromagnetics Research Letters, Vol. 4, 109-112, 2008.

5. Pozar, D. M. and D. H. Schaubert, Microstrip Antennas: The Analysis and Design of Microstrip Antennas and Arrays, IEEE Press, 1995.

6. Lai, H.-W. and K.-M. Luk, "Design and study of wide-band patch antenna fed by meandering probe," IEEE Trans. Antennas Propagat., Vol. 54, 564-571, Feb. 2006.
doi:10.1109/TAP.2005.863091

7. Lai, H.-W. and K.-M. Luk, "Wideband stacked patch antenna fed by meandering probe," Electron. Lett., Vol. 41, 297-298, Mar. 2005.
doi:10.1049/el:20057671

8. Mak, C.-L., H. Wong, and K.-M. Luk, "High-gain and wide-band single-layer patch antenna for wireless communications," IEEE Trans. Vehicular Technology, Vol. 54, 33-40, Jan. 2005.
doi:10.1109/TVT.2004.838899

9. Ghorbani, K. and R. B. Waterhouse, "Dual polarized wideband aperture stacked patch antennas," IEEE Trans. Antennas Propagat., Vol. 52, 2171-2174, Aug. 2004.
doi:10.1109/TAP.2004.832484

10. Rowe, W. S. T. and R. B. Waterhouse, "Reduction of backward radiation for CPW fed aperture stacked patch antennas on small ground planes," IEEE Trans. Antennas Propagat., Vol. 51, 1411-1413, June 2003.
doi:10.1109/TAP.2003.812250

11. Khodaei, G. F., J. Nourinia, and C. Ghobadi, "A practical miniaturized U-slot patch antenna with enhanced bandwidth," Progress In Electromagnetics Research B, Vol. 3, 47-62, 2008.
doi:10.2528/PIERB07112201

12. Ansari, J. A. and R. B. Ram, "Broadband stacked U-slot microstripp atch antenna," Progress In Electromagnetics Research Letters, Vol. 4, 17-24, 2008.

13. Ansari, J. A., P. Singh, and S. K. Dubey, "H-shaped stacked patch antenna for dual band operation," Progress In Electromagnetics Research B, Vol. 5, 291-302, 2008.

14. Ataeiseresht, R., Ch. Ghobadi, and J. Nourinia, "A novel analysis of minkowski fractal microstripp atch antenna," Journal of Electromagnetic Waves and Applications, Vol. 20, No. 8, 1115-1127, 2006.
doi:10.1163/156939306776930268

15. Bao, X. L. and M. J. Ammann, "Comparison of several novel annular-ring microstripp atch antennas for circular polarization," Journal of Electromagnetic Waves and Applications, Vol. 20, No. 11, 1427-1438, 2006.
doi:10.1163/156939306779274336

16. Bilotti, F., M. Manzini, A. Alu, and L. Vegni, "Polygonal patch antennas with reactive impedance surfaces," Journal of Electromagnetic Waves and Applications, Vol. 20, No. 2, 169-182, 2006.
doi:10.1163/156939306775777260

17. Abbaspour, M. and H. R. Hassani, "Wideband star-shaped microstripp atch antenna," Progress In Electromagnetics Research Letters, Vol. 1, 61-68, 2008.
doi:10.2528/PIERL07111505

18. Cui, B., J. Zhang, and X.-W. Sun, "Single layer microstrip antenna arrays applied in millimeter-wave radar front-end," Journal of Electromagnetic Waves and Applications, Vol. 22, No. 1, 3-15, 2008.
doi:10.1163/156939308783122797

19. Azadegan, R. and K. Sarabandi, "A novel approach for miniaturization of slot antennas," IEEE Trans. Antennas Propagat., Vol. 51, 421-429, Mar. 2003.
doi:10.1109/TAP.2003.809853

20. Sarabandi, K. and R. Azadegan, "Design of an efficient miniaturized UHF planar antenna," IEEE Trans. Antennas Propagat., Vol. 51, 1270-1276, June 2003.
doi:10.1109/TAP.2003.812239

21. Zheng, B. and Z. Shen, "Effect of a finite ground plane on microstrip-fed cavity-backed slot antennas," IEEE Trans. Antennas Propagat., Vol. 53, 862-865, Feb. 2005.
doi:10.1109/TAP.2004.841278

22. Luk, K.-M. and H. Wong, "A new wideband unidirectional antenna element," International Journal of Microwave and Optical Technology, Vol. 1, 35-44, June 2006.

23. Kong, J. A., Electromagnetic Wave Theory, Wiley, 1990.

24. Zhu, L., R. Fu, and K.-L. Wu, "A novel broadband microstrip-fed wide slot antenna with double rejection zeros," IEEE Antennas and Wireless Propagation Letters, Vol. 2, 194-196, 2003.
doi:10.1109/LAWP.2003.819689

Dr. Shi-Wei Qu

Dr. Jia-Lin Li

Dr. Quan Xue

Professor Chi Hou Chan