abstract This paper presents a simple technique to extend the aperture of planar composite right/left-handed (CRLH) metamaterial antennas with minimal impact on the antenna's dimensions. Unlike most CRLH antenna structures the proposed antenna is via-free. The proposed antenna is shown to operate over a wideband from UHF to C-band with good radiation characteristics. The antenna configuration consists of a vertically stacked CRLH unit cells comprising a patch and meandered lines, where the patch is engraved with an S-shaped slot. The design uses minimal ground plane area. The meander line inductance is grounded using coplanar waveguide (CPW) ground which eliminates conventional CRLH transmission line metallic via into ground plane. The antenna is feed through a coplanar waveguide (CPW) match stub that is electromagnetically coupled to the unit cells. Antenna dimensions are 17.5 × 32.15 × 1.6 mm3, which corresponds to 0.204 ¿0 × 0.375 ¿0 × 0.018 ¿0 where free-space wavelength (¿0) is 3.5 GHz. Parametric study enabled the optimization of the antenna performance in terms of impedance bandwidth, radiation gain, and radiation efficiency. Measured results confirm that the antenna can operate from 850 MHz to 7.90 GHz, which is equivalent to a fractional bandwidth of 161.14%. The antenna has a maximum gain and radiation efficiency of 5.12 dBi and ~80%, respectively, at 3.5 GHz. ©2018. American Geophysical Union. All Rights Reserved.
keywords composite right/left-handed metamaterials coplanar waveguide planar wideband antenna portable devices slot antenna wireless communication systems antenna grounds bandwidth coplanar waveguides directional patterns (antenna) efficiency electric impedance metamaterial antennas metamaterials mobile antennas slot antennas waveguides wireless telecommunication systems composite right/left-handed metamaterial coplanar wave-guide (cpw) crlh transmission lines free-space wavelengths portable device radiation characteristics wideband antenna wireless communication system microwave antennas