A Multi Channel Down-converter Module Exploiting Recent Advances in Multi layer RF Packaging Techniques

Recent advances in the design of digital signal processing (DSP) equipments have broadened the appeal of this technology to satellite customers. Each digital signal processor has up and down converters associated with it in order to interface with the rest of a payload RF subsystem, consequently the need for multi-channel frequency converters that can provide a low cost per channel solution is now of increasing importance. The subject of this paper is the design of such a multi channel down-converter that provides an L band to Baseband frequency conversion, which has typically 100-200 channels. The key factor in achieving the desired low cost per channel is the use of a multi layer, multi RF channel, high temperature cofired ceramic tile. This complex tile incorporates RF tracks as well as DC interconnections and local oscillator signal distribution. The module design presented in this paper uses 13 hybrids per RF channel, thus having 104 hybrids for a fully populated 8 channel down-converter module. This has been designed and developed by EADS Astrium UK as part of the next generation processor (NGP) development jointly funded with ESA