Latest developments in ultra-stable microwave oscillators at femto-ST institute

A growing number of scientific or technical applications requires very high frequency stability oscillators. Thus a frequency stability of the order of 1×10
^-14
at short term is now required for metrology, future space programs and some tests of fundamental physics. Besides any reduction in oscillators phase noise will improve radar systems and phase noise measurement sensitivity. These new requirements impose to surpass the performances of the state-of-the-art quartz crystal oscillators. Such a breakthough can today be effectively achieved by the Sapphire Whispering Gallery Mode Resonator technology. In this paper the new advances achieved in our laboratory, related to this technology, are presented.