A Simple and General Method for Filtering Power Divider With Frequency-Fixed and Frequency-Tunable Fully Canonical Filtering-Response Demonstrations

This paper proposes a general method to design the power divider (PD) with the arbitrary filtering response. The proposed model allows coupling matrix-based filter synthesis to be adopted in the Wilkinson PD (W-PD) design so that two-order, high-order, single-band, multiband, frequency-fixed, and frequency-tunable responses are all available for the W-PD. Meanwhile, benefiting from the generalized W-PD topology, the general model can be employed to design the PD with arbitrary termination impedances (TIs), arbitrary power division ratios (PDRs), and the highly favorable isolation. To demonstrate the proposed Wilkinson filtering PD (W-FPD), a series of resonator-coupled BPFs with open-end coupling feeding line and their corresponding coupling matrices are considered and applied to the W-FPD design. Accordingly, four frequency-fixed W-FPDs are designed to achieve four fully canonical responses with a full number of transmission zeros (TZs). In addition, two highly selective frequency-agile W-FPDs with the nearly constant absolute bandwidth (ABW) are designed to achieve the very wide frequency tuning range. The excellent simulation and measurement results experimentally validate that the proposed model can be utilized to realize W-FPD with two-order, high-order, single-band, multiband, equal, unequal, equal tunable, and unequal tunable filtering responses.