Abstract: A compact multilayer signal processing system. In the illustrative embodiment, the system is adapted for use with microwave signals. The system includes a first mechanism for receiving an input signal and selectively routing the input signal onto a first signal path. A second mechanism routes the input signal along the first signal path vertically through one or more layers to a first circuit component. The first circuit component outputs an adjusted signal in response to receipt of the input signal. A third mechanism directs the adjusted signal to the output of the system. In a specific embodiment, the one or more layers include one or more groundplane layers. In this embodiment, the first mechanism includes an input switching network in communication with a controller. The switching network is positioned on a switching layer and communicates with one or more controllers to facilitate selectively switching the input signal onto one of plural input signal paths.