A proposed design of ultra-wideband (UWB) monopole antenna has been presented to cover frequency range 2.49–14.42 GHz with small size. An equivalent circuit model with the parameter values of the optimized UWB antenna has been modeled. Moreover, a compatible lumped-elements utilized in equivalent circuit modeling for the proposed monopole antenna is established using the Advanced Design System (ADS). An UWB feeding network circuit has been designed in order to be used for exciting 2x1 and 4x1 linear antenna array. The measured and simulated results for the proposed feed network has a good return loss, isolation and power division ratio at all ports within the whole UWB frequency range. Two and four element UWB linear antenna arrays are presented. The average gain for the two-element antenna array is about 5.3 dBi and reaches to7.15 dBi for the four-element antenna array, over the whole UWB frequency range. A good agreement between the measured and the simulated results of all parameters for the antenna element and antenna arrays is appeared.