Negative Group Delay Phenomenon Analysis in Power Divider: Coupling Matrix Approach

This paper presents a negative group delay (NGD) phenomenon analysis of a power divider using the coupling matrix approach. The proposed power divider can provide an arbitrary power division ratio with a minimal effect on group delay variations. From the analysis, it is found that the proposed circuit can provide positive group delay (PGD) and NGD through different transmission paths. The NGD can be generated without a lumped resistor and can be controlled by source-resonator coupling and unloaded-quality factor (Qu) of resonators. For experimental validation, power dividers with PGD and NGD of 0.3 and -1 ns, respectively, were designed and fabricated. The measurement results agreed well with the simulation and the predicated values. The proposed power divider topology is useful for the performance improvement of microwave circuits and systems.