  A photonic millimeter wave local oscillator capable of producing two
microwatts of radiated power at 224 GHz has been developed. The device was
tested in one antenna of Smithsonian Institution's Submillimeter Array (SMA)
and was found to produce stable phase on multiple baselines. Graphical data is
presented of correlator output phase and amplitude stability. A description of
the system is given in both open and closed loop modes. A model is given which
is used to predict the operational behavior. A novel method is presented to
determine the safe operating point of the automated system.
