A novel compact tree-design antenna (NCTA) with the ability of reconfigurable ultra-wideband (UWB) of 3.1 GHz to 10.6GHz to five multi-narrowband applications is proposed. This antenna has a novel radiating element design that consists of seven small circles (7-filter) surrounding a central circle. Moreover, the NCTA incorporates the 7-filter that functioned as filter into the antenna design. The compact 38mm x 38mm antenna integrates three PIN diode switches, which are connected to a single National Instrument Data Acquisition (NI-DAQ) Board. The DAQ itself is controlled (ON/OFF state) by a virtual instrument known as "Lab VIEW Interface Software". The activation of specific PIN diode switches in the configuration that is controlled by the DAQ then, in turn, determines the frequency agility. The presented antenna is capable of performing up to five multi-bands. The operating frequencies are as follows; band 1 (2.72-11.8 GHz), band 2 (2.4-4 GHz, 5.3-11.6 GHz), band 3 (2.7-6.5 GHz, 7.1-11.6 GHz), band 4 (2.7-4.4 GHz, 5.2-6.5 GHz, 7.1-11.7 GHz) and band 5 (2.6-3.5 GHz, 4.8-7.0 GHz, 7.4 GHz-11.5 GHz). Furthermore, the antenna has a gain of up to 6dBi, which is considered better than that of conventional antenna. The proposed antenna produces a proficient divisive radiation pattern at 4 and 6 GHz. The experimental results exhibit the success of the antenna performance. It is competent as future candidate for cognitive radio and military applications.
2. Chen, Q., M. Kurahashi, and K. Sawaya, "Dual-mode patch antenna switched by PIN diode," IEEE Topical Conference on Wireless Communication Technology, 148-149, 2003.
3. Shynu, S. V., G. Augustin, C. K. Aanandan, P. Mohanan, and K. Vasudevan, "Design of compact reconfigurable dual frequencies microstrip antennas using varactor diodes," Progress In Electromagnetic Research, Vol. 60, 197-205, 2006.
4. Ghanem, F. , J. R. Kelly, and P. S. Hall, "Switched UWB to narrowband planar monopole antenna," European Conference on Antennas and Propagation, Barcelona, April 12-16, 2010.
5. Ali, , T. M., T. A. Rahman, M. R. Kamarudin, and M. N. Md Tan, "Reconfigurable linear array antenna with beam shaping at 5.8 GHz," Asia Pacific Microwave Conference, APMC, 2008.
6. Kiriazi, J., H. Ghali, H. Ragaie, and H. Haddara, "Reconfigurable dual-band dipole antenna on silicon using series MEMS switches," IEEE Antennas and Propagation Society International Symposium, Vol. 1, 403-406, 2003.
7. Ali, M. T., M. N. Md Tan, A. R. B. Tharek, M. R. B. Kamarudin, M. F. Jamlos, and R. Sauleau, "A novel reconfigurable planar antenna array (RPAA) with beam steering control," Progress In Electromagnetics Research B, Vol. 20, 125-146, 2010.
8. Shynu, S. V., G. Augustin, C. K. Aanandan, P. Mohanan, and K. Vasudevan, "Design of compact reconfigurable dual frequency microstrip antennas using varactor diodes," Progress In Electromagnetics Research, Vol. 60, 197-205, 2006.
9. Saed, M. A., "Reconfigurable broadband microstrip antenna fed by a coplanar waveguide," Progress In Electromagnetics Research, Vol. 55, 227-239, 2005.
10. Kamarudin, M. R. B., P. S. Hall, F. Colombel, and M. Himdi, "Electronically switched beam disk-loaded monopole array antenna," Progress In Electromagnetics Research, Vol. 101, 339-347, 2010.
11., , http://www.ni.com/labview/.
12. Panda, J. R., P. Kakumanu, and R. S. Kshetrimayum, "A wide-band monopole antenna in combination with a UWB microwave band-pass ¯lter for application in UWB communication system," Annual IEEE India Conference (Indicon), 2010.
13. Yoon, J. , D. Kim, and C. Park, "Implementation of UWB antenna with bandpass filter using microstrip-to-CPW transition matching," Asia Pacific Microwave Conference, APMC, 2009.
14. Sadat, S., M. Fardis, F. G. Gharakhili, and G. R. Dadashzadeh, "A compact microstrip square-ring slot antenna for UWB applications," Progress In Electromagnetics Research, Vol. 67, 173-179, 2007.
15. Lee, J. N. and J. K. Park, "Compact UWB chip antenna design using the coupling concept," Progress In Electromagnetics Research, Vol. 90, 341-351, 2009.
16. Sadat, S., M. Houshmand, and M. Roshandel, "Design of a microstrip square-ring slot filled by an H-shape slot for UWB applications," Progress In Electromagnetics Research, Vol. 70, 191-198, 2007.
17. Mokhtaari, M. and J. Bornemann, "Directional ultra-wideband antennas for planar technologies," Proceedings of the 38th European Microwave Conference, 2008.
18. Jusoh, M., M. F. Jamlos, M. R. B. Kamarudin, and M. F. B. A. Malek, "A MIMO antenna design challenges for UWB application," Progress In Electromagnetic and Research B, Vol. 36, 357-371, 2012.
19. Jusoh, M. , M. F. Jamlos, M. R. Kamarudin, F. Malek, M. H. Minhat, and M. A. Jamlos, "A novel compact tree-design antenna (NCTA) with high gain enhancement for UWB application," Journal of Electromagnetic Wave and Application, Vol. 25, No. 17-18, 2472-2486, 2011.