Designing a complex multi-chip module with high power requirements for an aerospace environment

Raytheon E-Systems has designed a Programmable Digital Receiver (PDRx) Multi-chip Module (MCM) for use in aerospace applications. The PDRx MCM is able to overcome the technical limitations of analog receivers without the size, power, and weight penalties typically associated with digital receiver technology. The PDRx design is comprised of four digital receiver channels accepting 16-bit-wide data streams at a frequency of 33 MHz (roughly a 10 MHz bandwidth per channel) with user programmable functions such as bandshifting, filtering, and postprocessing. The PDRx design is made possible through the use of highly efficient DSP algorithms implemented in VLSI technology, coupled with the processing power of 100 Mflops. The paper details solutions to some of the mechanical issues encountered in this design. These issues include the substrate design, ringframe design, thermal design, and lid concerns of the MCM