Methods of gain improvement of UWB antenna for WLAN application

Four simple, low-cost, and compact ultra-wideband antennas with elliptical slot patches are proposed. The basic shape of the radiation patch based on the elliptical slot remains unchanged. After the size adjustment of the patch, the four antenna structures cover the 5.15-5.875 GHz (WLAN) band. Keeping the antenna dimension unchanged, the loss in the dielectric substrate is reduced by double metal layers connected by vias for different feeding modes, so as to improve the antenna gain. The simulation results show that when different antenna structures cover the same frequency band the maximum gain increases by 0.9 dBi in the case of microstrip line feeding and 0.2 dBi in the case of coplanar waveguide feeding.