Improved switched multiplexer architecture for supporting carrier aggregation in front-end applications. In some embodiments, an N-plexing system can include an assembly of filters configured to provide N filtered paths, and a switching circuit in communication with the assembly of filters. The switching circuit can be configured to provide a plurality of switchable paths between the assembly of filters and an antenna port to allow simultaneous operation between the N filtered paths and the antenna port. In some embodiments, N can be 4 for a quadruplexing system or 2 for a duplexing system, and such a system can be implemented in a front-end module (FEM) for wireless devices.