A Wilkinson power divider with improved bandpass filtering and high isolation performance is proposed. These characteristics are achieved by replacing the quarter-wavelength transmission line in the conventional coupled line Wilkinson power divider with quarter-wavelength side-coupled ring (QSCR). Additional features such as DC blocking between arbitrary two ports, single-layer via-less structure for low-cost fabrication and convenient integration (as only one isolation resistor required) are highlighted. A 2-GHz Wilkinson microstrip power divider with a fractional bandwidth of 4% has been fabricated and experimentally characterized. The consistency between simulated and measured results validates the effectiveness of our proposed design.
