A Novel Filtering Power Divider With High Isolation and Wideband Reflectionless Characteristics

ABSTRACT A novel filtering power divider (FPD) with high isolation and wideband reflectionless characteristics is proposed. The wideband filtering characteristics of the FPD come from the joint contribution of the coupled lines and the stepped impedance resonator, where the coupled lines provide the passband characteristic, and the stepped impedance resonator generates and tunes the transmission zeros outside the passband to enhance out‐of‐band suppression and improve frequency selectivity. The absorption‐isolation network and absorptive stubs improve isolation between output ports while achieving input reflectionless characteristics. Through theoretical analyses and experimental verification, a prototype microstrip line was developed, with simulation results showing good agreement with measured data. Measured results indicate that the proposed FPD—with a center frequency of 2.47 GHz—delivers excellent isolation: better than 30 dB within the passband and superior to 22 dB over the entire 0 to 7 GHz frequency range. The input reflectionless bandwidth is up to 277% from 0 to 6.87 GHz.