use a frequency multiplier with VCO, PLL, comparator

use a frequency multiplier with VCO, PLL, comparator:-

The frequency multiplication is actually carried out quite cleverly in the phase-locked loop's feedback loop, by using a frequency divider on the output of the voltage controlled oscillator (VCO). This divided-down output is fed-back to the input comparator and compared to the reference frequency. Since the divided down frequency is smaller than the reference frequency, the comparator generates a voltage signal to the VCO, telling it to increase the output frequency. It continues to do this via the feedback loop, raising the VCO output frequency, until the divided-down frequency from the VCO output is equal to the reference frequency. At this point the comparator stabilizes and generates no more signals to the VCO, or only minor changes to maintain stability. The output frequency from the VCO will be stable at the input reference frequency multiplied by the value of the feedback divider.