(Preliminary)

Analog Frequency Multiplier

PL565-68 VCXO

AFM Phase Noise at 311.04MHz, using 155.52MHz crystal

AFM Spectrum at 311.04MHz, using 155.52MHz crystal

The analog frequency multiplication preserves the low phase noise of the quartz crystal oscillator while keeping

unwanted sub harmonics from the multiplication at very low levels. Sub harmonics appear only at large distance

from the carrier, far outside the loop bandwidth of a PLL that uses the AFM signal to multiply up further to a

multiple GHz network clock. This means that the impact of the sub harmonics on the application is negligible.