A High Front-to-Back Ratio 5G Base Station Antenna Based on Special-Shaped Reflector

In this paper, a high front-to-back ration $\boldsymbol{5}\mathbf{G}$ base station antenna based on special-shaped reflector is proposed. The radiating structure of the antenna is a pair of crisscross-shaped dipole which is fed by a L-shaped feeding structure. The antenna adopts a special-shaped reflector. By bending the two sides of the flat reflector and periodically grooving and slot a circular groove in the reflector, the induced current on the reflector is reduced and then the back radiation of the antenna is effectively reduced. And thus the front-to-back ratio is improved. The simulated results show that the proposed antenna has a wide impedance bandwidth of 40.5% with S11 $< -\boldsymbol{10}\ \mathbf{dB}$ and also achieves a high isolation. In addition, the half-power beamwidth of the antenna is $\boldsymbol{82.5}\pm 4^{\circ}$ at horizontal plane and a stable gain of $6.9\pm 0.13\ \mathbf{dBi}$ is also achieved over the working frequency band. And the front-to-back ratio increased by about 15dB compared with the flat reflector.