A Small, Low Phase Noise Design Of The Oven-controlled Crystal Oscillator

Oven-controlled crystal oscillators are widely used in the military electronic equipment and civilian communications for their high frequency stability. The indicators of oscillators are directly related to whether the objective can be accurately targeted by the radar system, whether the missile system is able to accurately hit the target, whether time can maintain synchronization in coordination. The indicators of oscillators are directly related to the communication quality and the clock accuracy in the civilian communications.This article describes the background of the project and its value, the technology base of an OCXO, introduces the design , method of calculation and analytical method of a small OCXO, introduces the methods of the circuit assembly and adjustment, describes the testing methods, gets the product's test results and analyzed briefly.This article focuses on the realization of the oven-controlled crystal oscillator,the solutions of the miniaturization, low aging, high stability, low phase noise and other key technology. We have achieved the miniaturization of the crystal oscillator by improving the temperature control method and structure installation.We have have achieved the crystal oscillator's low phase noise performance by designing a high Q value and low-noise quartz crystal resonator and designing a low noise circuit. We have achieved the high frequency- temperature stability and it stablizes rapidly by the use of SC cut crystal and the design of exact temperature controling circuit. We have inproved the aging properties of the crystal by the design of low aging crystal, pre-aging of electronic components, the reasonable control of the level of the OCXO crystal .Finally, in this article we have test the comprehensive indicators of the crystal oscillator .For example, the current ,the harmonics, the frequency components in the reference temperature, the stability ,the power the output power, the phase noise, etc. And we test the aging aspect of the crystals oscillator for 30 days. All the indicators of the crystal oscillator have achieved the anticipated goals.