Metamaterial inspired triband offset feed rectangular monopole for wireless applications

Abstract

A rectangular monopole engraved with an open complementary split-ring resonator (OCSRR) metamaterial is designed and proposed for multiband radio applications. The proposed antenna has a rectangular monopole feed with offset microstrip feed, and the OCSRR designed at 3.14 GHz is engraved in the radiating element. The OCSRR is a special type of metamaterial with small electrical size. The OCSRR modifies the current direction due to its negative permittivity, which creates another resonance at 3.16 GHz. The left offset feed and abridged ground length creates another resonance at 3.82 GHz and responsible for good impedance matching are achieved in all the resonating bands. The entire antenna is designed and fabricated on the FR4 substrate with a complete measurement equal to 27.84 mm x 23.25 mm x 1.6 mm. The proposed structure shows the multiband characteristics at 3.16 GHz, 3.82 GHz, and 5.14 GHz with a S 11 of -19.83 dB, -17.90 dB, and -55.73 dB, respectively. The critical parameters of the OCSRR are decided using the parametric analysis, and the simulated results are presented. The OCSRR negative permittivity extraction is done with NRW wave guide extraction method, and the result is validated with the help of OCSRR resonant frequency calculation. The uniformity is well maintained between the measured and simulated results. The multiband characteristics, reasonable gain, compactness, low design complexity, and small size are the significant features of the proposed antenna