High Speed RF Packaging Design and Fabrication for Ka-Band Radar Systems

The various choices of materials for RF packaging are reviewed and two groups of materials are used to package components for a Ka-band landing radar. A Kovar housing was designed and built for a transmit/receive module, which provides good RF performance and allows the high power semiconductor amplifiers to be mounted directly to pedestals at the bottom of the package. For the up/down converter, an Aluminum housing was designed and built with all connectors laser welded in place. Both packages are hermetic and capable of withstanding a differential pressure of over 30 psi. Environmental requirements are taken into consideration during package design, such as thermal cycling, absolute maximum temperature ratings of components and structural aspects. Details of the electrical package design to minimize radiation loss and cross talk are discussed, as well as various methods of attachment of the RF connectors to the housings.