Abstract
A miniaturized wideband and directional antenna is proposed for 4G base
station applications. To improve the front-to-back ratio, and
miniaturization of the proposed antenna, a metal cavity reflector is
designed. One cross-shaped and four rectangular slots are etched at the
center and edge of the radiating patch respectively to improve the
isolation. The coupling feeding is achieved by Y-shaped stubs printed on
the top of the substrate. Moreover, the prototype of the antenna was
fabricated and tested. The measured results show that the antenna
achieves a bandwidths ( s11<-10 dB) of 50.4% from 1.63 GHz to
2.73 GHz. And an average isolation and front-to-back ratio (FBR) between
the two ports is about 30 dB and 20 dB whereas the cross polarization
level maintains lower than -12 dB across the entire operating band. The
half-power beam width (HPBW) of around 79±3° and average gain of 8.0±1.0
dBi during the operating band are also obtained. Due to the metal
cavity, compared with other antennas of the same type, the proposed
antenna has a smaller size. The antenna has a wide bandwidth, high
isolation, stable radiation patterns, ideal FBR and smaller size, so it
is suitable for 4G base station applications.