622.08 MHz SMD-VCXO with filter [for optical transmission application]

This paper describes the 622.08 MHz SMD-VCXO, developed for optical transmission applications. By applying WDM technology, it is possible to transmit large volume data. The CDR (Clock Data Recovery), which must be connected with each wavelength signal, is required to be smaller and of lower height by system case size restriction. To transmit the data in high speed, high clock frequency is required. Also, the jitter that causes the transmission error must be reduced. In the oscillator, the fundamental mode 155.52 MHz is oscillated, and 622.08 MHz, which is the 4^th harmonic, is selected through the band pass filter instead of the conventional resonant circuit. This SMD-VCXO is miniaturized by such a circuit construction. We confirmed that all the target specifications were achieved and jitter was achieved 0.01 UI (Unit Interval) max