One varactor-tunable High Impedance Surface (HIS) is proposed and used in design of an active metamaterial absorber. The proposed HIS structure is based on mushroom-type HIS, in which varactors are introduced to adjust the effective capacitance and tune the resonance frequency. The primary ground plane is etched as the bias network for these loaded varactors, and another ultra-thin grounded sheet is attached to the bottom. In addition, the absorbing characteristics are introduced for dielectric loss to construct an active metamaterial absorber. Numerical simulations show that a wide tuning range can be achieved by adjusting the varactor capacitance, and effective absorption is realized at different states. Two identical absorbers, which are loaded with fixed-value chap capacitors of different capacitances, are fabricated and measured using a waveguide measurement setup. Excellent agreement between the simulated and measured results is demonstrated.
"A Varactor-Tunable High Impedance Surface for Active Metamaterial Absorber," Progress In Electromagnetics Research C,
Vol. 43, 247-254, 2013. doi:10.2528/PIERC13072202
1. Sievenpiper, D., L. Zhang, R. F. J. Broas, N. G. Alexopoulos, and E. Yablonovitch, "High-impedance electromagnetic surfaces with a forbidden frequency band," IEEE Trans. Microw. Theory Tech., Vol. 47, No. 1, 2059-2074, Oct. 2004.
2. Tretyakov, S. A. and S. I. Maslovski, "Thin absorbing structure for all incidence angles based on the use of a high-impedance surface," Microw. Opt. Technol. Lett., Vol. 38, No. 3, 175-178, 2003. doi:10.1002/mop.11006
3. Kelly, R., T. Kokkinos, and A. P. Feresidis, "Analysis and design of sub-wavelength resonant cavity type 2-D leaky-wave antennas," IEEE Trans. Antennas Propag., Vol. 56, No. 9, 2817-2825, Sep. 2008. doi:10.1109/TAP.2008.928791
4. Sievenpiper, D. F., J. H. Schaffner, H. J. Song, R. Y. Loo, and G. Tangonan, "Two-dimensional beam steering using an electrically tunable impedance surface," IEEE Trans. Antennas Propag., Vol. 51, No. 10, 2713-2722, Oct. 2003. doi:10.1109/TAP.2003.817558
5. Sievenpiper, D. and J. Schaffner, "Beam steering microwave reflector based on electrically tunable impedance surface," Electron. Lett., Vol. 38, No. 21, 1237-1238, 2002. doi:10.1049/el:20020863
6. Hum, S. V., M. Okoniewski, and R. J. Davies, "Realizing an electronically tunable reflectarray using varactor diode-tuned elements," IEEE Microw. Wireless Compon. Lett., Vol. 15, No. 7, 422-424, 2005. doi:10.1109/LMWC.2005.850561
7. Mias, C. and J. H. Yap, "A varactor-tunable high impedance surface with a resistive-lumped-element biasing grid," IEEE Trans. Antennas Propag., Vol. 55, No. 7, 1955-1962, 2007. doi:10.1109/TAP.2007.900228
8. Costa, F., A. Monorchio, and S. Talarico, "An active high-impedance surface for low-profile tunable and steerable antennas," IEEE Antennas and Wireless Propagation Letters, Vol. 7, 676-680, 2008. doi:10.1109/LAWP.2008.2006070
9. Costa, F. and G. P. Vastante, "Tunable high-impedance surface with a reduced number of varactors," IEEE Antennas and Wireless Propagation Letters, Vol. 10, 11-13, 2011. doi:10.1109/LAWP.2011.2107723
10. Brown, C. and T. Carberry, "A technique to simulate the self and mutual impedance of an array," IEEE Trans. Antennas Propag., Vol. 11, No. 3, 377-378, 1963. doi:10.1109/TAP.1963.1138022