High-frequency local oscillator transmission for the Atacama large millimeter array (ALMA)

The Atacama large millimeter array (ALMA) is an international radio astronomical facility currently under construction in Chile [Wooten, A et al., 2005]. Due to the unprecedented combination of high frequency and long baselines, and the requirement that it operate as an interferometer, the array requires Local Oscillators (LO) and LO references with extremely low phase-noise and phase drift. The LO requirements, design implementation, and preliminary results are presented.