Electrically Small Metamaterial-Inspired Tri-Band Antenna With Meta-Mode

Two novel metamaterial-inspired antennas applied for 4G mobile communication are proposed in this letter. Antenna 1 takes a triangular electromagnetic resonator (TER) as its radiator fed by a coplanar waveguide (CPW). After the model building and simulation, three frequency bands of
$1.78\sim 1.84~\hbox{GHz}$
,
$2.34\sim 3.86~\hbox{GHz}$
and
$5.75\sim 5.87~\hbox{GHz}$
are achieved. Each band is well matched except for the band 3. Therefore, Antenna 2 is further developed, which adds a complementary TER (CTER) on the ground, and the improved design has a good impedance matching in band 3 without influencing the first two bands. Both antennas have operational bands covering WiMAX in 1.8/3.5 GHz and WLAN in 5.8 GHz and omnidirectional radiation patterns during the operating bands. The proposed two metamaterials antennas have the advantages of simple fabrication, miniaturization and compactness, which can be applied to the 4G wireless mobile communication system.