The GPS-controlled frequency standards GPS-12(R) and the GLONASS/GPS-controlled frequency standard GPS-12RG deliver a precision frequency and time reference everywhere in the world. They gain their long-term frequency stability from Cesium standards in the navigation satellite systems GPS and GLONASS. They are also designed to provide very high short-term stability and are cost-efficient and extremely accurate frequency standards.

These reference sources are very suitable as frequency standards in the telecommunication and electronics industry. They fit both as stationary frequency references - for instance in test systems and as local references in the design department - and as portable, highly accurate reference sources for field use.

These instruments are off-air frequency standards with an internal architecture according to Figure 1-1. They have one antenna input and a number of optional frequency outputs.

There is also an option for disciplining with an external 1 pps source, e.g. an in-house cesium standard.

Fig 1-1. Simplified block diagram of the GPS-12X.