A Wideband High-Gain Cavity-Backed Low-Profile Dipole Antenna

In this communication, a compact, wideband, low-profile, and high gain dipole antenna is proposed. A microstrip coupling line is used to feed the ellipse pairs, which is two arms of the antenna. This simple feeding structure can significantly enhance the impedance bandwidth (IBW). A cavity-backed structure is adopted to achieve the low-profile antenna. With the influence of the cavity-backed structure, the new antenna has a higher gain over the whole frequency band. An optimized antenna with a height of only 0.17λ (where λ is the free space wavelength at the lowest frequency) is designed and measured. The measured result shows that the IBW for VSWR6 dBi) from 2.57 to 8.73 GHz is more than 108.9%. The antenna radiation pattern performs well over the whole band, and the peak gain can reach 11.8 dBi.