volume | PIER Journals

Abstract

In this paper a CPW-fed annular slot antenna is miniaturized with enhanced impedance bandwidth using a reactive impedance surface (RIS) substrate. Such meta-surface (RIS) is realized by patterning 3×3 array of circular elements over an inexpensive FR-4 substrate which is backed by a circular metallic plane. Due to the compensation of electric and magnetic energy stored by antenna and RIS substrate respectively, the antenna resonance frequency is shifted by 53.6% compared with a simple slot antenna. By the inclusion of such reactive surface, input impedance of the antenna is reduced, and a remarkable improvement in impedance bandwidth from 11.66% to 64.26% is also noticed. Therefore, both miniaturization and bandwidth enhancement are achieved simultaneously with the present loading technique. The directivity of the RIS loaded antenna is increased further by loading a concentric metallic ring over the RIS loaded structure at a height above the RIS plane. The Ring & RIS loaded structure is fabricated for measurement purpose. A good agreement is obtained between the simulated and measured results for both RIS loaded and Ring & RIS loaded configurations. The ring loading over the RIS antenna provides improvement in directivity about 5 dB. The peak gain and bandwidth are measured as -1.03 dBi and 58.62%, respectively.

1. Azadegan, R. and K. Sarabandi, "A novel approach for miniaturization of slot antennas," IEEE Trans. Antennas Propag., Vol. 51, No. 3, 421-429, Mar. 2003.
doi:10.1109/TAP.2003.809853

2. Ghosh, B., S. K. M. Haque, and D. Mitra, "Miniaturization of slot antennas using slit and strip loading," IEEE Trans. Antennas Propag., Vol. 59, No. 10, 3922-3928, Oct. 2011.
doi:10.1109/TAP.2011.2163754

3. Ghosh, B., S. K. M. Haque, and N. R. Yendruri, "Miniaturization of slot antenna using wire loading," IEEE Antennas and Wireless Propag. Lett., Vol. 12, 488-491, 2013.
doi:10.1109/LAWP.2013.2255857

4. Sun, L., B.-H. Sun, Q. Sun, and W. Huang, "Miniaturized annular ring slot antenna for small/mini UAV applications," Progress In Electromagnetics Research C, Vol. 54, 1-7, Oct. 2014.

5. Azadegan, R. and K. Sarabandi, "Bandwidth enhancement of miniaturized slot antennas using folded, complementary and self-complementary realizations," IEEE Trans. Antennas Propag., Vol. 55, No. 9, 2435-2444, Sep. 2007.
doi:10.1109/TAP.2007.904086

6. Abbosh, M. A., "Miniaturized microstrip-fed tapered-slot antenna with ultrawide band performance," IEEE Antennas and Wireless Propag. Lett., Vol. 8, 690-692, 2009.
doi:10.1109/LAWP.2009.2025613

7. Kikuta, K. and A. Hirose, "Compact folded-fin tapered slot antenna for UWB applications," IEEE Antennas and Wireless Propag. Lett., Vol. 14, 1192-1195, 2015.
doi:10.1109/LAWP.2015.2397008

8. Gong, B., X. S. Ren, Y. Y. Zeng, L. H. Su, and Q. R. Zheng, "Compact slot antenna for ultra-wide band applications," IET Microwave, Antennas and Propag., Vol. 8, No. 3, 200-205, 2014.
doi:10.1049/iet-map.2013.0067

9. Gao, G.-P., B. Hu, and J.-S. Zhang, "Design of a miniaturized printed circular-slot UWB antenna by half-cutting method," IEEE Antennas and Wireless Propag. Lett., Vol. 12, 567-570, 2013.
doi:10.1109/LAWP.2013.2259790

10. Sze, J.-Y. and K.-L. Wong, "Bandwidth enhancement of a microstrip-line-fed printed wide slot antenna," IEEE Trans. Antennas Propag., Vol. 49, No. 49, 1020-1024, Jul. 2001.

11. Mitra, D., D. Das, and S. R. Bhadra Chaudhuri, "Bandwidth enhancement of microstrip line and CPW-fed asymmetrical slot antennas," Progress In Electromagnetics Research C, Vol. 32, 69-79, Jun. 2012.
doi:10.2528/PIERL12032204

12. Jan, J.-Y. and J.-W. Su, "Bandwidth enhancement of a printed slot antenna with a rotated slot," IEEE Trans. Antennas Propag., Vol. 53, No. 6, 2111-2114, Jun. 2005.
doi:10.1109/TAP.2005.848518

13. Pan, G., Y. Li, Z. Zhang, and Z. Feng, "A compact slot-loop hybrid antenna with a monopole feed," IEEE Trans. Antennas Propag., Vol. 62, No. 7, 3864-3868, Jul. 2014.
doi:10.1109/TAP.2014.2320535

14. Fan, S. T., Y. Z. Yin, B. Lee, W. Hu, and X. Yang, "Bandwidth enhancement of a printed slot antenna with a pair of parasitic patches," IEEE Antennas and Wireless Propag. Lett., Vol. 11, 1230-1233, 2012.
doi:10.1109/LAWP.2012.2224311

15. Yun, S., D. Y. Kim, and S. Nam, "Bandwidth enhancement of a cavity-backed slot antenna using a via-hole above the slot," IEEE Antennas and Wireless Propag. Lett., Vol. 11, 1092-1095, 2012.

16. Emadian, S. R., C. Ghobadi, J. Nourinia, M. H. Mirmozafari, and J. Pourahmadazar, "Bandwidth enhancement of cpw-fed circle like slot antenna with dual band-notched characteristics," IEEE Antennas and Wireless Propag. Lett., Vol. 11, 543-546, 2012.
doi:10.1109/LAWP.2012.2199274

17. Mitra, D., B. Ghosh, A. Sarkhel, and S. R. B. Chaudhuri, "A miniaturized ring slot antenna design with enhanced radiation characteristics," IEEE Trans. Antennas Propag., Vol. 64, No. 1, 300-305, Jan. 2016.
doi:10.1109/TAP.2015.2496628

18. Mosallaei, H. and K. Sarabandi, "Antenna miniaturization and bandwidth enhancement using a reactive impedance substrate," IEEE Trans. Antennas Propag., Vol. 52, No. 9, 2403-2414, Sep. 2004.
doi:10.1109/TAP.2004.834135

19. Dong, Y., H. Toyao, and T. Itoh, "Design and characterization of miniaturized patch antennas loaded with complementary split-ring resonator," IEEE Trans. Antennas Propag., Vol. 60, No. 2, 772-785, Feb. 2012.
doi:10.1109/TAP.2011.2173120

20. Xu, H.-X., G.-M.Wang, J.-G. Liang, M. Q. Qi, and X. Gao, "Compact circularly polarized antennas combining meta-surfaces and strong space-filling meta-resonator," IEEE Trans. Antennas Propag., Vol. 61, No. 7, 3442-3450, Jul. 2013.
doi:10.1109/TAP.2013.2255855

21. Noghanian, S. and L. Shafai, "Gain enhancement of annular slot antennas," IEE Proc. Microw. Antennas Propag., Vol. 148, No. 2, 109-114, Apr. 2001.
doi:10.1049/ip-map:20010331

Dr. Gopinath Samanta

Dr. Debasis Mitra

Professor Sekhar Ranjan Bhadra Chaudhuri