The radio frequencies accessible to this telescope range from 194–408 gigahertz (1.545–0.735 mm) which includes rotational transitions of dozens of molecular species as well as continuum emission from interstellar dust grains.

Although the array is capable of operating both day and night, most of the observations take place at nighttime when the atmospheric phase stability is best.

The SMA project was begun in 1983 as part of a broad initiative by Irwin Shapiro, the then new director of the SAO, to produce high resolution astronomical instruments across the electromagnetic spectrum.

[1] The antennas were constructed at Haystack Observatory in Westford, Massachusetts, partially disassembled and trucked across the United States, then shipped by sea to Hawaii.

He found that the most uniform sampling of spatial frequencies, and thus the cleanest (lowest sidelobe) point spread function was obtained when the antennas were arranged in the shape of a Reuleaux triangle.

However the SMA site is a lava field with many rocky ridges and depressions, so the pads could not be placed in exactly the optimal positions.

Each antenna pad has a conduit connecting it to the central building, through which AC power cables, and optical fibers are pulled.

Multi-mode optical fibers are used for low bandwidth digital signals, such as ethernet and phone service.

The Sumitomo fibers have an extremely low coefficient of thermal expansion, which is nearly zero at the typical temperature below the surface of Mauna Kea.

[3] Each of the eight antennas has a 6 meter diameter primary mirror made of 72 machined cast aluminum panels.

They are supported by a carbon fiber tube backup structure, which is enclosed by aluminum panels to protect it from windblown debris.

After the antennas were deployed, the surfaces were measured using near-field holography with a 232.4 GHz beacon source mounted on the exterior cat-walk of the Subaru building, 67 meters above the SMA's subcompact pad ring.

This temperature-controlled cabin nearly encloses the antenna's steel mount to minimize pointing errors due to thermal changes.

The correlator chips were designed at MIT Haystack, and funded by five institutions: SMA, USNO, NASA, NRFA and JIVE.

The new correlator operates at only one spectral configuration, uniform 140 kHz per channel resolution across the entire bandwidth.