Low-Profile Complementary Dipole Antenna Using Semicircular Sector Electric Dipoles

A novel slot-combined complementary antenna composed of semicircular sector electric dipoles is proposed. Two pairs of semicircular sector electric dipoles are properly incorporated to yield a low-profile, complementary dipole antenna. The advanced antenna is measured with a relatively thin profile of 0.042-wavelength and the maximum front-to-back ratio (FBR) of the fabricated antenna can reach up to 12.7 dB. Measured results show that the mode of the slot element and the mode of the semicircular sector electric dipoles can be incorporated and the impedance bandwidth is 2.38~3.11 GHz (i.e., 25.0% in fraction) with an available quasi-unidirectional radiation bandwidth of 24.6%.