UWB planar out-of-phase Wilkinson power divider utilizing UWB ±90° phase shifters in microstrip-slot technology

The design of a planar out-of-phase (180°) power divider in microstrip-slot technology exhibiting an ultra wideband (UWB) operation is presented. The device uses a single dielectric substrate and is formed by a two-way in-phase Wilkinson divider with two ±90° phase shifters in its output arms. The phase shifters are formed by double microstrip to slotline transitions that offer compatibility with the microstrip Wilkinson divider while providing an UWB performance. The simulated and measured results of the proposed out-of-phase divider show equal power division with desired phase characteristics, good return loss at the three ports, low insertion losses, and fine isolation between the two output ports across the band from 2 GHz to 12 GHz.