Spectrometers currently employed or under development by NASA are based on a PCB including FPGAs and a number of other discrete components. An ASIC based spectrometer offers a great reduction in weight, volume and power consumption compared to the FPGA based implementation. This proposal aims to prove the feasibility (Phase I), develop and test (Phase II) a 10GHz 4K frequency bin polarimetric spectrometer ASIC.
The ASIC will digitize two 10GHz RF signals using 6-bit 20GS/s ADCs, channelize each input signal’s spectrum into 212 (4096) frequency bins, and then accumulate either spectral power or the Stokes parameters for each bin. In order to implement the required functionality and meet the specifications, the proposed ASIC will include state-of-the-art ADCs, a PLL, poly-phase filter based FFT cores, an accumulation block, a data readout function, a digital control unit and testing features. Tolerance to at least 200krads of TID radiation and immunity to the SEEs will be achieved by employing radiation hardening by design, by layout, by system level techniques, and also by applying an ultrathin gate oxide technology for implementation. The power consumption will be reducible by allowing specific applications to switch off portions of the spectrum, reduce the bin count and the sample rate.