A Novel Planar Printed Dual-Band Magneto-Electric Dipole Antenna

In this paper, a novel planar printed dual-band magneto-electric dipole antenna is proposed. The proposed antenna is composed of a conventional bow-tie patch as an electric dipole, a semi-circular loop that operates as a magnetic dipole, a coplanar ground plane, and a wideband microstrip-to-coplanar-stripline transition balun. By etching a pair of complementary capacitively loaded loop slots on the bow-tie radiation patch, a notched band is introduced to form the dual-band antenna. And a coplanar ground is adopted to make the entire antenna become a planar printed structure. Additionally, the proposed antenna loads the periodical interdigital capacitance structure on the semi-circular loop for the purpose of making the current flowing along the loop maintain the same phase and improving the performances of the magnetic dipole. The proposed antenna was fabricated and measured. The measured results keep in good accordance with the simulated ones. Consequently, the proposed antenna achieves a dual-band operation at 2.37~2.82 GHz (17.3%) and 3.14~4.10 GHz (26.5%) with the Voltage Standing Wave Ratio (VSWR) less than 2, so it can be applied for WLAN (2.4-2.484 GHz) and WiMAX (2.5-2.69 GHz/3.4-3.69 GHz). Meanwhile, the stable gain, symmetrical, and stable unidirectional radiation patterns, low cross polarization, and low back lobe are also obtained at the dual bands.