OXCO is actually a normal quartz crystal oscillator that is housed in a mini thermostatic oven in order to maintain an constant (required) temperature at all times and conditions.
Changes in the temperature can cause a drift in the center frequency and drastically jeopardize the calibrated output parameters. And therefore, the use of oven-controlled crystal oscillators becomes eminent.
Aside from the oven, quartz crystal temperatures are also managed by providing it with various forms of trimming known as “Cuts,” which also aids in preserving the pulse’s stability.
However, it is necessary to carry out checks and recalibrate crystal and heat element aging to ensure accurate performance at all times.
OCXO is the top-performing quartz with remarkable frequency stability. As a result, they are used in the precision applications and systems like cell towers, commercial radio transmitters, and military communication equipment.
Though an OXCO is bigger, expensive, and consumes a greater power than its regular equivalents, it compensates for these disadvantages by providing super frequency stability over a long period of time that the conventional oscillators cannot offer.
There are two types of Oven-ized crystal oscillators available on the market:
1) Precision oven-controlled crystal oscillators and2) High precision (Low Phase Noise) OCXO
These are used basis the application designs and circuitry needs. See Raditek website.