Compact 45° phase shifter based on coupled tapered transition for UWB applications

In this paper, a new Ultra-wideband (UWB) phase shifter is proposed. The design is based on UWB coupled tapered transition etched on Rogers RT5880 substrate. Theoretical formulas defining the important characteristics of the structure are also derived. The manufactured device is compact since its total dimension is 40×20×1mm
³
. A good agreement is achieved between simulation and measurement; hence the observed output phase shift is around 45°±5°, the return loss is more than 10 dB and the insertion loss is less than 1 dB within the UWB, i.e., 3–10.6 GHz.