In this paper we propose a new method to enhance the gain of rectangular waveguide antenna arrays using the double negative medium (DNG) structure composed of strip wires (SW) and split ring resonators (SRR). The electromagnetic parameters of the DNG structure are retrieved and the rectangular waveguide antennas with and without the DNG structure are studied using numerical simulation method. The simulation results show that the DNG structure can congregate the radiation energy when the index of refraction approximates zero,since that the gain of the antenna arrays is enhanced and the radiation performance of the antenna arrays is effectively improved. Far-field radiation patterns are measured, which indicate that this method is effective to enhance the gain.
2. Pendry, J. B., A. J. Holden, W. J. Stewart, and I. Youngs, "Extremely low frequency plasmons in metallic mesostructures," Phys. Rev. Lett., Vol. 76, No. 25, 4773-4776, 1996.
doi:10.1103/PhysRevLett.76.4773
3. Pendry, J. B., A. J. Holden, D. J. Robbins, and W. J. Stewart, "Magnetism from conductors and enhanced nonlinear phenomena," IEEE Trans. Microwave Theory Tech., Vol. 47, No. 11, 2075-2084, 1999.
doi:10.1109/22.798002
4. Smith, D. R., W. J. Padilla, D. C. Vier, S. C. Nemat-Nasser, and S. Schultz, "Composite medium with simultaneously negative permeability and permittivity," Phys. Rev. Lett., Vol. 84, No. 18, 4184-4187, 2000.
doi:10.1103/PhysRevLett.84.4184
5. Enoch, S., G. Tayeb, P . Sabouroux, N. Guerin, and P. Vincent, "A metamaterial for directive emission," Phys. Rev. Lett., Vol. 89, No. 21, 1-4, 2002.
doi:10.1103/PhysRevLett.89.213902
6. Wu, B.-I., W. Wang, J. Pacheco, X. Chen, T. Grzegorczyk, and J. A. Kong, "A study of using metamaterials as antenna substrate to enhance gain," Progress In Electromagnetics Research, Vol. 51, 295-328, 2005.
doi:10.2528/PIER04070701
7. Sui, Q., C. Li, L. L. Li, and F. Li, "Experimental study of λ/4 monopole antennas in left-handed metamaterial," Progress In Electromagnetics Research, Vol. 51, 281-293, 2005.
doi:10.2528/PIER04011202
8. Li, B., B. Wu, and C. H. Liang, "Study on high gain circular waveguide array antenna with metamaterial structure," Progress In Electromagnetics Research, Vol. 60, 207-219, 2006.
doi:10.2528/PIER05121101
9. 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