volume | PIER Journals

Abstract

Herein is presented a two-dimensional negative permittivity unit cell for coaxial notch filter applications. This novel unit cell is developed through simulation in the context of an ideal infinite parallel plate waveguide, and preliminary implementation is demonstrated through simulation and measurement in a finite parallel plate waveguide. Finally, the unit cells are incorporated as an in-line notch filter in a coaxial transmission line, and their efficacy is demonstrated through simulation and measurement. The unit cell developed for this application was formed as a broadband fractal expansion of the traditional capacitively loaded strip. A partial repetition of the basic CLS I-shape was inserted in the capacitive gap on either side of the structure. This new unit cell was developed and simulated in HFSS using an incident TEM wave excitation in a parallel plate waveguide, and was shown to have two resonant frequencies of interest. The first resonance produces a wide bandwidth of negative permittivity (29.5%) from 1.3 GHz to 1.75 GHz; the second produces a region of negative permeability from 2.05 GHz to 2.45 GHz, a bandwidth of 17.8%. The current on the structure at each of these frequencies is presented, along with the pertinent fields in the waveguide. The effects of various alterations to the basic shape of the unit cell are also presented.

1. Wongkasem, N., A. Akyurtlu, J. Li, A. Tibolt, Z. Kang, and W. D. Goodhue, "Novel broadband terahertz negative refractive index metamaterials: Analysis and experiment," Progress In Electromagnetics Research, Vol. 64, 205-218, 2006.
doi:10.2528/PIER06071104

2. Hudlika, M., J. Machac, and I. Nefedov, "A triple wire medium as an isotropic negative permittivity metamaterial," Progress In Electromagnetics Research, Vol. 65, 233-246, 2006.
doi:10.2528/PIER06102703

3. Weldon, T. P., K. Miehle, R. S. Adams, and K. Daneshvar, "A wideband microwave double-negative metamaterial with non-Foster loading," Proc. IEEE Southeastcon, 1-5, 2012.

4. Ziolkowski, R. W., "Design, fabrication, and testing of double negative metamaterials," IEEE Trans. Antennas Propag., Vol. 51, No. 7, 1516-1529, 2003.
doi:10.1109/TAP.2003.813622

5. De, T. M., M. Luque, N. R. K. Devarapalli, and C. Christodoulou, "Investigation of bandwidth enhancement in volumetric left-handed metamaterials using fractals," Progress In Electromagnetics Research, Vol. 131, 185-194, 2012.

6. Smith, K. L. and R. S. Adams, "A λ_◦/60 spherical spiral metamaterial for negative permeability and negative permittivity," IEEE Int. Symp. on Ant. and Prop. (APSURSI), 719-720, 2016.

7. Miyamaru, F., Y. Saito, M. W. Takeda, B. Hou, L. Liu, W. Wen, and P. Sheng, "Terahertz electric response of fractal metamaterial structures," Phys. Rev. B, Vol. 77, 045124.1-045124.6, 2008.

8. Li, D. and J. Mao, "Koch-like sided Sierpinski gasket multifractal dipole antenna," Progress In Progress In, Vol. 126, 399-427, 2012.

9. Smith, Smith, R. S. Adams, and T. P. Weldon, "A novel broadband fractal metamaterial unit cell," IEEE Int. Symp. on Ant. and Prop., 549-550, 2014.

10. Khan, O., Z. Islam, I. Rashid, F. Bhatti, and Q. Islam, "Novel miniaturized Koch pentagonal fractal antenna for multiband wireless applications," Progress In Electromagnetics Research, Vol. 141, 693-710, 2013.
doi:10.2528/PIER13060904

11. Li, D. and J. Mao, "Sierpinskized Koch-like sided multifractal dipole antenna," Progress In Electromagnetics Research, Vol. 130, 207-224, 2012.
doi:10.2528/PIER12060108

12. Liu, R., A. Degiron, J. J. Mock, and D. R. Smith, "Negative index material composed of electric and magnetic resonators," Appl. Phys. Lett., Vol. 90, No. 26, 263504.1-263504.3, 2007.

13. Szabo, Z., G. Park, R. Hedge, and E. Li, "A unique extraction of metamaterial parameters based on Kramers-Kronig relationship," IEEE Trans. Microw. Theory Tech., Vol. 58, No. 10, 2646-2653, 2010.
doi:10.1109/TMTT.2010.2065310

14. Shehan, J.W., R. S. Adams, and T. P.Weldon, "Metamaterial measurement in a cylindrical coaxial fixture with consideration for inter-element coupling," IEEE Radio Sci. Mtg., 138-138, 2014.

15. 15, H., G. Wang, and Q. Peng, "Fractal-shaped complementary electric-LC resonator for bandstop filter ," Progress In Electromagnetics Research, Vol. 23, 205-217, 2011.

16. Ebrahimi, A., W. Withayachumnankul, S. Al-Sarawi, and D. Abbott, "Dual-mode behavior of the complementary electric-LC resonators loaded on transmission line: Analysis and applications," J. Appl. Phys., Vol. 116, 083705-083705, 2014.
doi:10.1063/1.4893751

Dr. Kathryn Smith

Dr. Ryan S. Adams