ALMA North American Integration Center Front-End Test System

摘要

The Atacama Large Millimeter/submillimeter (ALMA) Array Front End (FE) systemis the first element in a complex chain of signal receiving, conversion,processing and recording. 70 Front Ends will be required for the project. TheFront End is designed to receive signals in ten different frequency bands. Inthe initial phase of operations, the antennas will be fully equipped with sixbands. These are Band 3 (84-116 GHz), Band 4 (125-163 GHz), Band 6 (211-275GHz), Band 7 (275-373 GHz), Band 8 (385-500 GHz) and Band 9 (602-720 GHz). Itis planned to equip the antennas with the missing bands at a later stage ofALMA operations, with a few Band 5 (163-211 GHz) and Band 10 (787-950 GHz)receivers in use before the end of the construction project. The ALMA Front End is far superior to any existing receiver systems;spin-offs of the ALMA prototypes are leading to improved sensitivities inexisting millimeter and submillimeter observatories. The Front End units arecomprised of numerous elements, produced at different locations in Europe,North America and East Asia and are integrated at several Front End integrationcenters (FEIC) to insure timely delivery of all the units to Chile. The NorthAmerican FEIC (NA FEIC) is at the National Radio Astronomy Observatory facilityin Charlottesville, Virginia, USA. This paper describes the design and performance of the test set used at theNA FEIC to check the performance of the Front Ends, following integration andprior to shipment to Chile.