Multiband antenna using +1, −1, and 0 resonant mode of DGS dual composite right/left handed transmission line

The multiband antenna using defected ground structure (DGS) dual composite right/left handed transmission line (D-CRLH TL) is proposed. The D-CRLH TL resonator can provide a multiband using positive, zero, and negative modes without the different length resonators because the D-CRLH TL has inherent three bands in half periodicity. To design and analyze the proposed antenna, the circuit simulation of the two stage DGS D-CRLH resonator is executed by the equivalent circuit and the results are compared with those of full wave simulation and experiment. The results show that the presented antenna has such a reasonable radiation characteristics of efficiency, bandwidth, and size that it is suitable for compact multiband antenna. In addition, a theoretically unexpected radiation mode, which is generated by the DGS, is observed in the stop band. This additional mode could be utilized for the multi-band antenna. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2485–2488, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24649