ABSTRACTThe convergence paradigm of today, which can be characterized as multi function and high effectiveness, strongly requires an integration of RF/analog function and high-speed digital function into a single IC or package. System on Package (SOP) is a promising technology for system integration in order to meet these current trends and requirements. A passive embedded substrate is one of the most critical issues to achieve small-size and high-functional devices and modules with high integration density and deign flexibility for wireless communications.This paper will describe integration approach for passive embedded substrate for RF applications. With the several examples such as multi-band front end module and passive/active integrated modules, the advantages of the integration using passive embedded substrates will be described with some design considerations.