A Dual-Band Asymmetrical Metamaterial Antenna for Orthogonal Radiation Patterns

Abstract A new metamaterial antenna with dual resonant modes is presented using an asymmetrical periodic arrangement for orthogonal radiation patterns. The proposed antenna produces two orthogonal modes by the asymmetrical periodic unit-cell arrangement. The orthogonal resonant mode provides perpendicular radiation patterns without changing the antenna polarization at each resonant mode. The fabricated antenna shows good agreements with the theoretical analysis of the electric-field. The experimental results shows the orthogonal radiation patterns along x- and y-axises, and gains are 3.34 and 3.86 dBi at each radiating resonant mode, respectively. Additionally, slotted ground structures are embedded on the back side of the antenna in order to reduce the size and enhance the radiation efficiency of 12 % and 27 %, respectively.Key Words : Composite right/left-handed transmission lines (CRLH-TLs), Magnetic monopole antennas, Microstrip patch antennas, Dual-band antennas, Orthogonal radiation patterns.