A Dual-Mode UWB Antenna for Pattern Diversity Application
Jun Feng Liu, Wenxuan Tang, Meng Wang, Hao Chi Zhang, Hui Feng, Xiaojian Fu, Tie Jun Cui
Abstract
A dual-mode ultrawideband (UWB) antenna is proposed in this communication. The proposed antenna is composed of a monopole and a dipole sharing the same structure, which is excited by a coplanar waveguide (CPW) in even mode and odd mode, respectively. To achieve this kind of excitation, we present a dual-mode feeding structure with high isolation. Because the field distributions for the odd and even modes in CPW are opposite, and far-field patterns radiated by the two modes are orthogonal, this antenna has high isolation between two feeding ports. Fabricated antennas are measured, and good agreement with the simulation results is observed. The achieved impedance bandwidths of 10 dB return loss are 2.8-20 GHz and 4.4-17.6 GHz, with the isolation of 15 dB over the entire operating bandwidth, making it a good candidate for UWB multiple-input-multiple-output applications.