The specification describes an MCM package which contains both a digital MCM and an RF MCM in a stacked configuration. The package contains means for isolating RF signals from digital signals. In one case the digital MCM substrate is attached to the system substrate and the RF MCM substrate is attached...http://www.google.com.au/patents/US20020079568?utm_source=gb-gplus-sharePatent US20020079568 - Stacked module package
