A COMPACT DISPERSIVE DELAY LINE USING MICROSTRIP LINES AND OPENED SLOT LINES

A dispersive delay line (DDL) with compact size, good group delay, and all pass response in 200–800MHz band is presented. The proposed DDL is composed of a main microstrip transmission line with two shunted open stubs and two complementary slot lines, and a coupling slot line in ground plane. The length of the complementary slot line is reduced approximately from λg/2 to λg/4 through the upper end being opened, hence achieves miniaturization for the proposed DDL (λg is the guided wavelength at the center frequency). The overall area is 0.196 × 0.093λg with a peak group delay time of 3.2 ns. The proposed DDL has the advantages of compactness, good capability, and easy fabrication without any external matching network.