A system for obtaining a frequency reference constantly locked to L1 GPS carrier for distributed power quality assessment

The need to deploy distributed power quality monitoring systems requires the development of circuits able to yield an accurate time reference that is easy to disseminate on specific monitoring sites. In this paper, the design and initial realization of a time reference continuously traceable to a Cs133 atomic standard is proposed. Such reference is based on the locking of the Cesium-derived L1 GPS satellites carrier and would simply require visibility of one GPS satellite in order to be operative. In particular, attention is focused on the hybrid design and realization of the carrier tracking section, with particular emphasis on its fundamental building blocks, such as the voltage controlled oscillator, mixers, and power dividers. The design procedure for the different blocks and some prototypes are discussed and preliminary measurements showing their functionality are presented.