Devices and methods related to radio-frequency filters on silicon-on-insulator substrate

A radio-frequency (RF) device 150 comprises a silicon die 104 having a first side, a second side and a plurality of vias 108 providing an electrical connection between the first side and the second side. A RF circuit 158 including a switch is implemented at or near the first side. Mounting features 168, such as bump solders, are provided on the second side. At least some of the vias facilitate an electrical connection between the RF circuit and the mounting features. The RF device further comprises a RF flip-chip 102 including a filter, the RF flip-chip being mounted on the first side of the silicon die and in communication with the RF circuit. The RF device 150 may be a wafer-level-chip-scale package mounted on a packaging substrate as part of an RF module. The RF module may be used to route a RF signal between an antenna and a receiver as part of a wireless device.