Removing cosite interference using tunable filter technology

During the development of the tunable multicoupler used within the Joint Surveillance Target Attack Radar Subsystem (JSTARS), many sources of intermodulation were discovered. Additionally, the definition of the test system used to measure these products proved quite significant in determining the final system solution. The authors provide an overview of the JSTARS tunable multicoupler and the related performance criteria, a short tutorial on intermodulation concepts, a description of the original multicoupler performance, a description of the test system and how it evolved, and a presentation of the final multicoupler performance and how it was achieved