High functional density low-temperature co-fired ceramic modules for satellite communications

For satellite communication downlinks in the Ku/K-band we have integrated active semiconductor switching circuits with high-resolution passive components into a ceramic module for a 4 × 4 single-pole multi-throw reconfigurable switch matrix. The modular design includes different types of transmission lines, transitions, impedance matching circuits, and biasing and decoupling networks enabling digitally controlled reconfiguration. As a first step towards a complete, hermetically sealed, package, we have designed and characterised sub-modules incorporating individual active and passive components, to identify the limits of the technology. The scattering parameters measured for a stack of eleven layers, with the top layer and four embedded layers containing RF signal lines and minimum line widths of 40 μm, prove the principle-of-operation. The performance was found to be limited, at present, by the switch-ICs and their first-level interconnections, and can be still improved significantly.