Thermal characterization of crystal ovens used in phase noise measurement system

In this paper, the thermal stability characterization of crystal ovens used in a phase noise measurement system of ultra-low noise crystal resonators is proposed. This bench is dedicated to test 5 MHz and 10 MHz crystal devices packaged in HC40 enclosures. New double ovens have been designed to improve the ultimate noise floor of our carrier suppression bench. A brief description of the temperature environment and processing are given. In addition, experiments to measure the thermal stability of the oven control are given. These new crystal ovens present an Allan standard deviation of about 2-10^-15 at 1 s in terms of relative frequency fluctuations