Methods for transformer signal coupling and impedance matching for flip-chip circuit assemblies are presented. In one embodiment, a method for providing an inductive coupling between dies may include fabricating a first inductor on a first die using a passive process, fabricating a second inductor on a second die using a semiconductor process, and assembling each die so the first and second inductor are configured as a transformer. In another embodiment, a method for matching impedance in an RF circuit fabricated using flip-chip techniques may include passing an RF input signal through a first inductor formed using a passive process, inducing a time varying magnetic flux in proximity to a second inductor formed using an active process, and passing an RF signal induced by the time varying magnetic flux through the second inductor.