Description: Spectrometers currently employed by NASA include field programmable arrays (FPGAs), analog to digital converters (ADCs) and a number of other discrete components assembled on a printed circuit board (PCB). An application specific integrated circuit (ASIC) based spectrometer offers a great reduction in weight, volume and power consumption compared to the FPGA/PCB based implementation. This proposal aims to develop a low-power (LP) poly-phase spectrometer (PPS) ASIC. The proposed ASIC aims to achieve a 4GHz bandwidth and 8192 usable frequency bins. In order to implement the required functionality and meet the specifications while consuming below 1.5W of power, the proposed ASIC will include a state-of-the-art 6-bit ADC, a demultiplexer, a poly-phase filter bank, a windowing function, a fast-Fourier-transform core, a frequency-domain data analysis block, a data readout, a digital control unit and testing features. Tolerance to at least 500Krads of total ionizing dose (TID) radiation will be achieved by implementing the ASIC using an ultra-thin gate oxide CMOS technology. Low power consumption will be achieved by employing special multiplier-less-accumulators and multiplier-less-“butterflies”. The power consumption will be further reduced by minimizing the redundant states in the poly-phase filter’s FIR and IFFT block. Additional power-saving can be achieved by switching off the ASIC’s unused blocks, and by internally dividing the clock frequency. Phase I work provided the proof of feasibility of implementing the proposed spectrometer ASIC. Phase II will result in the silicon proven ASIC’s prototypes ready for commercialization in Phase III.

Benefits: The proposed spectrometer ASIC will greatly reduce the size, complexity, power consumption and will increase reliability of spectrometer instruments. These spectrometers are required for current and future space borne and airborne NASA's passive remote sensing instruments for exploration of the cosmic microwave background, the Earth's atmosphere and its surface. Specific missions include: A-SLMS, CAMEO, GACM, GeoSTAR, HyspIRI and GEO-CAPE. In addition, the proposed ASIC can find application in Earth based radio telescopes used for radio astronomy.

In addition to its primary application in the NASA's spectrometer systems, the proposed ASIC will be targeting applications in commercial, military and other scientific exploration systems which require small size, low power, radiation hardened spectrometers. Commercial and military applications include spectrometers employed on satellites, aircraft and air balloons for remote sensing and surveillance to process the data from synthetic aperture radars, sonars, or visible light/infrared/UV image detectors. Space, airborne and ground based remote sensing instruments employed by Environmental Protection Agency (EPA) and National Oceanic and Atmospheric Administration (NOAA) require high precision spectrometers for temperature, water vapor, pollutant, ozone and other exploration.