Group Delay Analysis Approach for Quasi-Reflectionless Power Divider With Flat Phase Difference

In this paper, we present a group delay (GD) analysis approach for designing a quasi-reflectionless filtering power divider with arbitrary prescribed flat phase difference. The proposed quasi-reflectionless filtering power divider consists of Wilkinson divider, coupled lines and series resistor connected open-circuited stubs. To achieve flat phase difference, GD should be same through both output ports of power divider. In addition, arbitrarily prescribed GD flatness and phase difference flatness are controlled by series connected resistors. The proposed design method is validated through experimental results by fabricating quasi-reflectionless power divider with 90° phase difference at center frequency of 3.50 GHz. The measurement results are consistent with simulation and theoretical predicted results.