A new approach to the design of a dual-band IFA with a metamaterial unit cell

This article proposes a new approach to obtaining a dual-band inverted-F antenna (IFA) with a novel metamaterial unit cell providing a negative index of refraction. The dual-resonance characteristic of the proposed IFA can be achieved because of the stop-band property of the metamaterial unit cell. The novel metamaterial unit cell of the proposed antenna has a positive refractive index (PRI), a negative refractive index (NRI), and the stop-band property between PRI and NRI. In addition, to control the resonant frequency of the proposed antenna, a capacitor is loaded in the metamaterial unit cell. To prove the validity of the proposed antenna, the properties of a homogeneous frequency-dependent (HFD) material, which can be represented in the HFSS software, are used. The metamaterial is replaced by the HFD material to confirm the effective constitutive parameters of the metamaterial unit cell. It is confirmed that the results using the metamaterial and the HFD material are similar. To prove the validity of the proposed design approach, a good agreement between experimental results and theoretical predictions is demonstrated, meaning that the approach is usable for practical applications. (C) 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett, 54:545-549, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26554