Implementation of a W-CDMA direct-conversion IQ modulator module including evaluation of chip-package-board interactions

Abstract

This paper presents a W-CDMA direct-conversion IQ modulator MMIC design that employs a new technique to generate the 90deg phase shift with low implementation loss. The package and PCB effects on the implemented IQ modulator MMIC when further developed as a board module are studied. The package and PCB interconnects are analyzed using the 3-D EM simulation tool and transformed into the equivalent-circuit elements for co-simulation with the IQ modulator MMIC. The degradation of error vector magnitude and sideband suppression due to the presence of package and PCB can be well predicted by the co-simulation results and then verified by the final measurement results