Negative group delay power dividers

Power dividers have been widely adopted as basic building components in microwave circuits and systems and extensively studied over the past decades including the unequal and tunable power division ratio, circuit miniaturization, and multiband operation. Because the group delay (GD) can influence the performances of RF/electronic circuits and systems, understanding the effect of GD has become critical for communication systems. However, GD analysis of power divider has rarely been considered in previous works and the positive GDs have only been provided through different transmission paths. In this chapter, several topologies of power divider and coupler with the predefined NGD characteristics will be presented including equal and unequal power division ratios. Similarly, coupling matrix synthesis with finite unloaded-quality resonators will be also presented in this chapter to design the power divider with the predefined NGD.