A tunable filtering antenna (filtenna) realized using rings fed with an ultra-wideband (UWB) planar, elliptical monopole antenna is proposed. An array of slotted rings with varactors is placed in close proximity of the planar monopole to obtain the low profile tunable filtenna. The array of rings can be viewed as a small tunable frequency selective surface. The design produces a tuning range of about 3.8-4.4 GHz over a varactor reverse bias voltage of 1-4 V.
2. Luo, G. Q., et al., "Filtenna consisting of horn antenna and substrate integrated waveguide cavity FSS," IEEE Trans. Antennas Propag., Vol. 55, No. 1, 92-98, 2007.
3. Bayatpur, F. and K. Sarabandi, "Miniaturized FSS and patch antenna array coupling for angle-independent, high-order spatial filtering," IEEE Microw. and Wireless Compon. Lett., Vol. 20, No. 2, 79-81, 2010.
4. Bichelot, F., R. Loison, and L. L. Coq, "FSS-EBG antenna with improved directivity bandwidth: Theory, design and measurements," Antennas and Propag. Soc. Int. Symp., 5423-5425, 2007.
5. Zhan, S. , R. J. Weber, and J. Song, "Effects of frequency selective surface (FSS) on enhancing the radiation efficiency of metal-surface mounted dipole antenna," IEEE/MTT-S Int. Microw. Symp., 1659-1662, 2007.
6. Russo, I., L. Boccia, G. Amendola, and G. D. Massa, "Tunable pass-band FSS for beam steering applications," Proc. of the 4th European Conf. on Antennas and Propag., 1-4, 2010.
7. Bayatpur, F., "Metamaterial-inspired frequency-selective surfaces,", Ph.D. Thesis, Electrical Engineering, University of Michigan, Ann Arbor, MI, 2009.
8. Mias, C., "Varactor-tunable frequency selective surface with resistive-lumped-element biasing grids," IEEE Microw. Wireless Compon. Lett., Vol. 15, No. 9, 570-572, 2005.
9. Mias, C., "Waveguide and free-space demonstration of tunable frequency selective surface," Electron. Lett., Vol. 39, No. 11, 850-852, 2003.
10., , Ansoft Corporation. Ansoft HFSS.
11. Lu , Y. , Y. Huang, Y. C. Shen, and H. T. Chattha, "A further study of planar UWB monopole antennas," Antennas & Propag. Conf., 353-356, Loughborough, UK, 2009.