A Synchronous Oscillator (SO) is a synchronization and tracking network which has high noise rejection properties while maintaining wide tracking range. In contrast to conventional tracking networks the noise rejection properties of a SO can be adjusted independently from its tracking range. A 70 MHz SO can track -60 dBm injected carriers with -20 dB carrier-to-noise ratio and maintain 400 KHz tracking range at these injection levels, while its resolution bandwidth can be few KHz. (The carrier to noise ratio is referenced to IF filter bandwidth which is 76 MHz (5-pole) for 120 Mbit/s data rate.) The acquisition time of SOs, under normal operation, can be below 100 nseconds. This paper discusses five SO carrier recovery techniques and presents experimental results.
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