CARRIER WAVE RECOVERY CIRCUIT

摘要

A carrier wave recovery circuit for recovering a carrier wave from a double-binary phase-modulated carrier wave containing a clock frequency component is disclosed. The circuit includes a frequency doubler to which the modulated wave is applied. A signal branching circuit passes the output through two parallel band-pass filters which derive, respectively, two components equal to twice the carrier wave frequency plus and minus the clock frequency. These two frequency components are separately mixed with the clock frequency component which is synchronized with the modulation rate of the modulated wave and the resulting signals are combined and frequency doubled. This frequency doubled signal is combined with the output of another frequency doubler which is connected to an output of the signal branching circuit in parallel with the two band-pass filters. A carrier wave synchronization circuit derives a synchronized carrier wave from this combined signal. The circuit ensures that a stable synchronized recovered carrier can be obtained without the necessity for an excessive wide band frequency multiplier.