New concepts of internally heated quartz resonators (IHQRs) and appropriate OCXOs

The design of internally heated quartz resonators (IHQRs) is discussed. IHQR is a combination of quartz crystal and an oven in a one hermetically sealed package with vacuum thermal insulation. The major advantage of IHQRs is very low power consumption. Improvement of the frequency stability of IHQRs and OCXOs is then considered by further improving the design of IHQR itself in order to minimize influence of heat transfer through heat radiation and conductivity of the residual gases in a vacuum package and by introduction of an additional oven for the circuitry of the oscillator. This additional oven will also serve as an external oven for IHQR itself, i.e. such approach may be considered as attempt to build double oven OCXO based on IHQR