Design of a multi-layer wideband antenna with high isolation for 3G repeater system

In this paper, an wideband antenna with high isolation characteristic for 3G repeater systems is proposed. The proposed antenna has a hollow conducting cylinder transition to improve the impedance matching. Metal walls are added to enhance isolation between donor and server antennas. The designed antenna has VSWR below 1.5:1, gain over 8.9 dBi, and isolation (S21) between server and donor antennas below -70dB over the frequency bands from 1.92 GHz to 2.5 GHz.