MDC Antenna Working Group Reports
Up-to-date information on the MMA Antennas can be found in Chapter 4 of the MMA Project Book.
History of MMA Antenna Development
In 1992, the MMA project began looking at antenna designs which would allow fast position switching to achieve phase stable observations a large fraction of the time. Work began on a "slant-axis" antenna design (ie, MMA Memos 94, 97, 98, 101, 105, 106). The stiffness of this design allowed very fast switching.
The slant-axis design evolved into an off axis parabaloid. The advantages of this off axis, slant-axis design included good gravitational performance, lack of counterweights, and the high sensitivity of an unblocked aperture.
A minimum blockage conventional antenna design, patterned after the BIMA 6 meter antennas, was prompted to provide a cost and performance comparison for the off axis, slant-axis design. In a side by side comparison, the off axis design was eliminated from consideration due to its poor field-of-view and polarization performance. Correction for the field-of-view and polarization was possible, but at the expense of the off axis design's sensitivity advantages.
Last update: March 03, 2000