20 GSPS ADC For Spectrometer Backends In Microwave Radiometers

This SBIR Phase II proposal requests support for Alphacore, Inc. to design and characterize a 20GS/s (giga-samples per-second), 6-bit, low-power, and low-cost analog-to-digital converter (ADC) ASIC with backend polyphase filter banks (PFB) based digital processing (DSP) for use in a wide range of NASArsquo;s microwave sensor based remote sensing applications.nbsp;Alphacorersquo;s newnbsp;single-core ADCnbsp;designed in the GlobalFoundries 22FDXnbsp;22nm FDSOInbsp;processnbsp;allows full Nyquist rate conversion of input signals up to 20 GHz. The maximum sampling rate is 24 GS/s, resolution is 6nbsp;bits (effective number of bits, ENOB = 4.5 bits) and the power consumption is belownbsp;250mW (115mW core ADC + 134mW output interface) without counting the on-chip DSP. This is possible because of Alphacorersquo;s innovative ldquo;digital foldingrdquo; Flash ADCnbsp;architecture. The low power supplynbsp;value ofnbsp;0.8Vnbsp;availablenbsp;innbsp;the 22FDXnbsp;process also helps in keeping the power consumptionnbsp;at a lower levelnbsp;than what is possible in most comparable CMOS processes. The ADC will have an analog input bandwidth of 20GHz making it possible to sample and convert signals on the full second Nyquist band, which provides significant benefits to many applications. Alphacore will also make the ADC radiation-tolerant, whichnbsp;enables its usenbsp;in space-borne applications.nbsp;Alphacore#39;s ADC provides unprecedented performance in terms of bandwidth and resolution at low power levels, in addition to radiation hardness, which opens possibilities for new and improved instruments and missions. Having such an ADC and other critical designs already available gives Alphacore a crucial advantage in developing a fieldable system by the end of thenbsp;SBIRnbsp;developmentnbsp;cycle.nbsp;