Arcetri Technical Reports 2/2001

Atacama Large Millimiter Array
A MMIC sampler for ALMA - Design report 

G. Collodi, G. Comoretto

Osservatorio Astrofisico di Arcetri

Abstract

A sampler circuit for the Atacama Large Millimiter Array, based on a GaAs 0.12-micron process, has been designed and tested by simulation. The use of a separate sampler before the CMOS digitizer allows a longer time for quantization decision, and reduces the timing requirements on the digitizer. The predicted performances fulfill the requirements for the ALMA sampler/digitizer. In particular the aperture time is < 50 ps, and the bandwidth in excess of 4 Ghz. The chip is now being fabricated and will be tested in spring 2001.