Advanced Direct Digital Exciter for Radar (ADDER)

CEI is currently funded for development of a Direct Band Pass Under sampling (DBPU) design of 900 MHz (approximately) center RF using an ADC clock of 1000 MHz. The RF bandwidth is approximately +/- 50 MHz (i.e. the same as the current SPS-49 radar). This yields an aliased spectrum centered around 100 MHz which is then easily digitally down converted via a digital LO following the ADC. It therefore makes sense for CEI to illustrate here the possibility of a design which combines both transmit and receive high performance ADCs and DACs; the exciter and receiver cannot be designed without a holistic DREX approach, even if they are not co-located. CEI will leverage an MDA/Navy Phase II SBIR that produced a system called RARE: Radar Advanced Receiver Exciter. This is leveraged in the DPBU SPS-49/general radar RF receiver design. The Army and Air Force have also funded expansion of the RARE concept and product line. The specific requirements needed for the MDA systems were the primary algorithmic focus of the research in Phase I; current and future MDA customer targeted algorithm and design specifications for PRF, waveforms, modes, receivers/exciters, discrimination capabilities, etc.