In this paper, a bandwidth enhancement technique of asymmetrical slot antennas with two different excitation methods is presented. One method of excitation is the microstrip line feed, and the other is the coplanar waveguide feed. The rectangular slot excited by microstrip line feed gives an impedance bandwidth of 14.76% (|S11| < −10 dB). When the rectangular slot is excited by a coplanar waveguide (CPW), it gives an impedance bandwidth of 26.61%. Both impedance and radiation characteristics of these antennas are studied.
2. Abbaspour, M. and H. R. Hassani, "Wideband star shaped microstrip patch antenna," Progress In Electromagnetics Research Letters, Vol. 1, 61-68, 2008.
3. Ansari, J. A. and R. B. Ram, "Broadband stacked U-slot microstrip patch antenna," Progress In Electromagnetics Research Letters, Vol. 4, 17-24, 2008.
4. Ansari, J. A., R. B. Ram, and P. Singh, "Analysis of a gap-coupled stacked annular ring microstrip antenna," Progress In Electromagnetics Research B, Vol. 4, 147-158, 2008.
5. Ansari, J. A., P. Singh, N. P. Yadav, and B. R. Vishvakarma, "Analysis of shorting pin loaded half disk patch antenna for wideband operation," Progress In Electromagnetics Research C, Vol. 6, 179-192, 2009.
6. Behdad, N. and K. Sarabandi, "Bandwidth enhancement and further size reduction of a class of miniaturized slot antennas," IEEE Trans. Antennas and Propag., Vol. 52, No. 8, 1928-1935, Aug. 2004.
7. Latif, , S. I., L. Shafai, and S. K. Sharma, "Bandwidth enhancement and size reduction of microstrip slot antennas," IEEE Trans. Antennas Propag., Vol. 53, No. 3, 994-1003, Mar. 2005.
8. Sadat, S., M. Houshmand, and M. Roshandel, "Design of a microstrip square-ring slot antenna filled by an H-shape slot for UWB," Progress In Electromagnetics Research,, Vol. 70, 191-198, 2007.
9. 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 Electromagnetics Research, Vol. 76, 237-242, 2007.
10. Dastranj, A. and H. Abiri, "Bandwidth enhancement of printed E-shaped slot antennas fed by CPW and microstrip line," IEEE Trans. Antennas Propag., Vol. 58, No. 4, Apr. 2010.
11. Chair, R., A. A. Kishk, K.-F. Lee, C. E. Smith, and D. Kajfez, "Microstrip line and CPW FED ultra wideband slot antennas with U-shaped tuning stub and reflector," Progress In Electromagnetics Research, Vol. 56, 163-182, 2006.
12. Chen, W. S. and K. Y. Ku, "Broadband design of non-symmetric ground λ/4 open slot antenna with small size," Microwave Journal, Vol. 50, 110-121, 2007.
13. Dastranj, A. and M. Biguesh, "Broadband coplanar waveguide-fed wide-slot antenna," Progress In Electromagnetics Research C, Vol. 15, 89-101, 2010.
14. Chen, D. and C.-H. Cheng, "A novel compact ultra-wideband (UWB) wide slot antenna with via holes," Progress In Electromagnetics Research, Vol. 94, 343-349, 2009.
15. Chen, B. , Y.-C. Jiao, F.-C. Ren, L. Zhang, and F.-S. Zhang, "Design of open slot antenna for bandwidth enhancement with a rectangular stub," Progress In Electromagnetics Research Letters, Vol. 25, 109-115, 2011.
16. HFSS ver. 11, Ansoft Corporation, , Pittsburgh.
17. Prakash, D. and R. Khanna, "Design and development of CPW-FED microstrip antenna for WLAN/WiMAX applications," Progress In Electromagnetics Research C, Vol. 17, 17-27, 2010.