Mixed LF/RF MCM

Over recent years, the miniaturisation of R.F. functions was based on the use of hybrid technology. That included thin or thick film capability, micro or macro R.F. packages and the design of MMICs. In the same time, many developments were running around the MCM technology for low frequency applications. This paper presents the work made, then the results, to get a mixed L.F./R.F. MCM which could benefit from all the developments made both for the R.F. packages and MCM. This mixed L.F./R.F. MCM is based on a high temperature cofired multilayer ceramic with two hermetic areas. Components, including an ASIC, are bonded in the low frequency part. The high frequency part is made of four cavities with R.F. connections through ceramic feedthroughs. MMICs and alumina substrate are bonded into those different cavities. The results show a ratio 2:1 for weight and volume reduction in comparison with an already advanced design made of separate micropackage and a multilayer polyimide PCB for the low frequency part. This is achieved with equivalent electrical performances. A full description of a channel amplifier (CAMP), using this technology, and working in the range of 10-13 GHz is presented. This CAMP is the base for a space qualification of this mixed technology.