Complementary Microstrip-Slotline Stub Configuration for Group Delay Engineering

A microstrip shunt open-stub overlapping a shorted slotline is presented and used to design a novel wideband dispersive delay line. The inherent periodic transmission zeros due to the resonances of an open-stub and a shorted slotline can be removed by using the complementary configuration. Moreover, the phase response of the complementary stub is frequency dependant which is used to design a dispersive delay line. The group delay profile of the complementary stub is smooth and continuous while at the same time maintaining a flat magnitude response over an ultra-wide bandwidth. Several units can be cascaded to obtain a desired group delay profile. This configuration can be used in analog signal processing or to reduce the signal distortion from other wideband components.