Project Title:

A Superconducting 10GHz 2-bit Digitizer for Radio Astronomy

HYPRES, Inc.
175 Clearbrook Road
Elmsford, NY 10523

93-1		08.16	1190			Amount Requested $69,424

A Superconducting 10GHz 2-bit Digitizer for Radio Astronomy

Abstract:

Hypres proposes to develop an ultra-sensitive 10GS/s Analog to 
Digital Convertor (ADC) for direct conversion of the SIS 
(Superconductor-Insulator-Superconductor) mixer output signals to 
digital data for use in radio astronomy.  The observation of 
broadband emitters, such as cosmic dust clouds and proto-planetary 
objects, requires a large instantaneous bandwidth for analysis of 
multiple spectral lines.  For these observations a sample rate of 
10GS/s is desired.  The 10GS/s ADC is constructed from three 
comparators and digital logic.  HYPRES proposes to design, 
fabricate, and test an innovative comparator design based on 
Superconducting Quantum Interference Devices (SQUIDs).  SQUIDS have 
demonstrated the energy resolution required for 2K noise thresholds 
at 5GHz bandwidths.  The complete ADC will be fabricated using 
niobium which operates at 4K, is compact (1mm x 1mm), and low power 
( < 1mW) making it suitable for space-based imaging arrays 
requiring an ADC per pixel.  HYPRES has developed superconducting 
digital logic which can be used to crosscorrelate the ADC data at 
10GS/s.  The design would the follow the ADC with a 1 to N 
demultiplexor, this will produce N output ports at l/N of the 
sample rate, each port is connected to a semiconductor correlator.  
A second approach would implement a superconducting correlator 
operating at 10GS/s.

The comparator devices developed in Phase 1 can be used to make 
10GS/s Analog to Digital Convertors and lps Time to Digital 
Convertors.  These are the key components for many commercial test 
and measurement instruments as well as all high energy and nuclear 
physics detectors.

Analog-to-Digital Convertor, Sub-mm Wave, Radio Astronomy, 
Superconductivity, Comparator, SIS Mixer, Digitizer, correlation