Wideband Out-of-Phase Filtering Power Divider With Arbitrary Power Dividing Ratio and High Selectivity

In this paper, a novel Filtering Power Divider(FPD) is proposed. This design consists of three parts: Marchand baluns constructed from two pairs of coupled lines and a terminal short-circuited stub, resonators loaded with two terminal short-circuited stubs, and two pairs of coupled resonators. This design generates four transmission zeros to improve selectivity. According to the design, good in-band isolation in the passband is achieved by connecting grounding resistors with two transmission lines at the central symmetry plane of the output ports of the baluns and coupled resonators. Simulation results show that this device achieves a 41% operating bandwidth, insertion losses of 9.57 dB and 0.52 dB, a power division ratio of 8:1, and a phase error of 1.8%, along with excellent in-band matching, out-of-band selectivity, and isolation.