The Millimeter Array

A brief review of the purpose and the design of the Millimeter Array, (MMA) is given. Particular attention is paid to the effects of the atmosphere and to millimeter-wavelength components, which are the antennas, the low-noise input stages, and the local oscillator system. The MMA is a radioastronomy instrument planned for construction at the National Radio Astronomy Observatory. in the 1990s. It will consist of 40 antennas working in the range 30 to 350 GHz for imaging cosmic sources with an angular resolution as fine as 0.06 arcseconds. The antennas are to be movable between sets of foundations so as to provide four two-dimensional configurations in which the overall size of the array can be varied from 70 m to 3 km. The angular resolution can thereby be selected to match a wide range of astronomical requirements.<>