This paper presents a new unequally spaced and excited resonant slotted-waveguide antenna array. It is realized by employing an improved resonant-slot coupled cavity chain composite right/left-handed (CRLH) waveguide. As the CRLH waveguide works at the infinite wavelength frequency, all the slot elements along the waveguide wall are excited in-phase. Thus both the element spacings and excitation amplitudes are introduced into the synthesis to realize a resonant slotted-waveguide antenna array. A seven-element unequally spaced and excited antenna array which generates pencil beam is synthesized, simulated and fabricated. The results show, with comparison to the equally spaced but unequally excited resonant slotted-waveguide antenna array, the proposed unequally spaced and excited array produces a lower peak sidelobe level (PSLL).
2. Eleftheriades, G. V. and K. G. Balmain, Negative-Refraction Metamaterials: Fundamental Principles and Applications, Wiley-IEEE Press, 2005.
3. Eshrah, I. A., et al., "Rectangular waveguide with dielectric-filled corrugations supporting backward waves," IEEE Trans. Antennas Propag., Vol. 53, No. 11, 3298-3304, Nov. 2005.
4. Liao, S., et al., "Left-handed transmission line based on resonant slot coupled cavity chain," IEEE Microw. Wireless Compon. Lett., Vol. 17, No. 4, 292-294, Apr. 2007.
5. Ueda, T., et al., "Dielectric-resonator-based composite right/left-handed transmission lines and their application to leaky wave antenna," IEEE Trans. Microw. Theory Tech., Vol. 56, No. 10, 2259-2269, Oct. 2008.
6. Ikeda, T., et al., "Beam-scanning performance of leaky-wave slot-antenna array on variable stub-loaded left-handed waveguide," IEEE Trans. Antennas Propag., Vol. 56, No. 12, 3611-3618, Dec. 2008.
7. Abdelaziz, A. F., et al., "Realization of composite right/left-handed transmission line using coupled lines," Progress In Electromagnetics Research, Vol. 92, 299-315, 2009.
8. Monti, G., R. De Paolis, and L. Tarricone, "Design of a 3-state reconfigurable CRLH transmission line based on MEMS switches," Progress In Electromagnetics Research, Vol. 95, 283-297, 2009.
9. Jimenez-Martin, J. L., et al., "Dual band high efficiency class CE power amplifier based on CRLH diplexer," Progress In Electromagnetics Research, Vol. 97, 217-240, 2009.
10. De Castro-Galan, D., L. E. Garcia Munoz, D. Segovia-Vargas, and V. Gonzalez-Posadas, "Diversity monopulse antenna based on a dual-frequency and dual mode CRLH ratrace coupler," Progress In Electromagnetics Research B, Vol. 14, 87-106, 2009.
11. Si, L.-M. and X. Lv, "CPW-fed multi-band omni-directional planar microstrip antenna using composite metamaterial resonators for wireless communications," Progress In Electromagnetics Research, Vol. 83, 133-146, 2008.
12. Yu, A., F. Yang, and A. Elsherbeni, "A dual band circularly polarized ring antenna based on composite right and left handed metamaterials," Progress In Electromagnetics Research, Vol. 78, 73-81, 2008.
13. Liao, S., Y. Chen, J. Wei, and J. Xu, "Unequally spaced resonant slotted-waveguide antenna array based on the infinite wavelength propagation property of composite right/left-handed waveguide," IEEE Antennas and Wireless Propag. Lett., Vol. 9, 451-454, 2010.
14. Hrabar, S., H. Kumric, and D. Zaluski, "Investigation of guiding and radiating properties of resonant-slot coupled cavity chain," 3rd European Conference on Antennas and Propagation, 3147-3150, 2009.
15. Unz, H., "Linear arrays with arbitrarily distributed elements," IEEE Trans. Antennas Propaga., Vol. 8, 222-223, Mar. 1960.
16. Kumar, B. P. and G. R. Branner, "Design of unequally spaced arrays for performance improvement," IEEE Trans. Antennas Propag., Vol. 47, No. 3, 511-523, Mar. 1999.
17. Allen, M. A. and G. S. Kino, "On the theory of strongly coupled cavity chains," IEEE Trans. Microw. Theory Tech., Vol. 8, No. 3, 362-372, May 1960.
18. Bevensee, R. M., "Propagation in the helical and narrow-band slow wave structures," IRE Trans. on Electron Devices, Vol. 8, No. 6, 549-558, 1961.
19. Ramo, S., J. R. Whinnery, and T. V. Duzer, Fields and Waves in Communication Electronics, John Wiley & Sons, Inc., 1994.
20. Marcuvitz, N., Waveguide Handbook: Four-terminal Structures, Peter Peregrinus, 1986.
21. Pozar, D. M., Microwave Engineering, 3 Ed., John Wiley & Sons, Inc., 2005.
22. HFSS, Version 12.0.0, Ansoft Corporation, Pittsburgh, USA, 2009.
23. Milligan, T. A., Modern Antenna Design, 2 Ed., John Wiley & Sons, Inc., 2005.
24. Bhattacharyya, A. K., Phased Array Antennas, John Wiley & Sons, Inc., 2006.