Dispersion Analysis of Shielded Asymmetrical Coplanar Stripline and Its Broadband Transition to Microstrip

Abstract

The dispersion analysis of shielded asymmetrical coplanar stripline (SACPS) and its broadband transition to microstrip at 6–50 GHz is presented. The SACPS has low dispersion and then can be highly conducive to broadband applications. The SACPS and microstrip line can propagate the quasi-TEM dominant mode, but have different characteristic impedance. Firstly, a broadband transition between the SACPS and the defected ground microstrip line which has the same characteristic impedance of the SACPS is designed. Then, a broadband transition between the defected ground microstrip and the microstrip line which has the characteristic impedance of 50 Ω is designed by using a tapered impedance matching section. Finally, two SACPS-microstrip transitions are combined by the back-to-back structure. The I/O ports are the 2.4 mm coaxial connectors which operate at DC-50 GHz. The simulation and measurement results agree well.