Multi-Functional Composite RF Four-Way Switch

This paper describes the design and fabrication of an active four-port microwave switching network embedded into a multi-layer aerospace composite structure. The multifunctional design is based on three broadband Integrated Device Technology (IDT) F2972 single-pole-double-throw (SP2T) RF switches and also includes a control and power supply circuit. The composite structure has been developed using a pre-impregnated structural glass material (Hexcel HexPly 914E). The conductive tracks of the switch and its ground plane have been fabricated using a non-woven carbon-nickel-copper veil material and a semi-flexible conducting silver ink. The manufacturing was also based on a hybrid manufacturing approach. The conductive veil was transferred onto the un-cured pre-preg material using a laser ablation method. Post-curing, the flexible silver ink was printed onto the surface to create the control circuits. The RF performance of the design has been evaluated and indicates the overall performance was consistent with measured S-parameters of the same circuit fabricated on Rogers 5880 substrate.