A rectangular slot antenna for UWB applications is proposed in this paper. The slot is designed in stepped configuration and is excited by an L-shaped microstrip line flared at the end. The measured impedance bandwidth (-10 dB) from 3 GHz to 27 GHz is achieved. The radiation patterns are bidirectional in the E plane and omnidirectional in the H plane with the measured peak gain around 5 dBi throughout the band. The experimental results are in good agreement with the simulated results. A detail parametric study is done for the flare angle and the flare width to axis ratio and their effect on the impedance bandwidth and the reflection coefficient is described.
2. Chulvanich, C., J. Nakasuwan, N. Songthanapitak, N. Anantrasirichai, and T. Wakabayashi, "Design narrow slot antenna for dual frequency," PIERS Online, Vol. 3, No. 7, 1024-1028, 2007.
3. Khunead, G., J. Nakasuwan, N. Songthanapitak, and N. Anantrasirichai, "Investigate rectangular slot antenna with L-shaped strip," PIERS Online, Vol. 3, No. 7, 1076-1079, 2007.
4. Behdad, N. and K. Sarabandi, "A multiresonant single-element wideband slot antenna," IEEE Antennas and Wireless Propagation Letters, Vol. 3, No. 1, 5-8, 2004.
5. ithisopa, K., J. Nakasuwan, N. Songthanapitak, N. Anantrasirichai, T. Wakabayashi, and , "Design CPW fed slot antenna for wideband applications," PIERS Online, Vol. 3, No. 7, 1124-1127, 2007.
6. Jiao, J.-J., G. Zhao, F.-S. Zhang, H.-W. Yuan, and Y.-C. Jiao, "A broadband CPW-fed T-shape slot antenna," Progress In Electromagnetic Research, Vol. 76, 237-242, 2007.
7. Pozar, D. M., Microwave Engineering, 4th Ed., John Wiley & Sons Inc., 2011.
8. Douville, R. J. P. and D. S. James, "Experimental study of symmetric microstrip bends and their compensation," IEEE Transactions on Microwave Theory and Techniques, Vol. 26, 175-181, 1978.
9. Gupta, K. C., R. Garg, I. J. Bahl, and P. Bhartia, Microstrip Lines and Slotlines, 2nd Ed., Artech House Publications, 1996.
10. Kim, J. P. and W. S. Park, "Network modeling of an inclined and off-center microstrip-fed slot antenna," IEEE Transactions on Antennas and Propagation, Vol. 46, No. 8, 1182-1188, 1998.
11. Yoshimura, Y., "A microstripline slot antenna (short papers)," IEEE Transactions on Microwave Theory and Techniques, Vol. 20, No. 11, 760-762, 1972.
12. Tu, W.-H. and K. Chang, "Miniaturized CPW-fed slot antenna using stepped impedance resonator," 2005 IEEE Antennas and Propagation Society International Symposium, Vol. 4A, 351-354, 2005.
13. Huang, X. D., C. H. Cheng, and L. Zhu, "An ultrawideband (UWB) slotline antenna under multiple-mode resonance," IEEE Transactions on Antennas and Propagation, Vol. 60, No. 1, 385-389, 2012.