Frequency synthesizer - Frequency Multiplier- Difference?

Both Frequency synthesizer - Frequency Multiplier can be incorporated using PLL.What is the difference between the two both functionally and in construction part of it.

GD

Frequency multiplier is a non-linear circuit. It utilizes harmonic for generating other frequencies. The output would be f = 2f0, 3f0 etc. that is the hamornic of the fundanetal. PLL generates frequency using a VCO.

boy wrote:
Do you say that the PLL is linear?

In a PLL frequency synthersizer the relationship between the n value that the VSO output is divided by and the output frequency will be linear over the range of frequencys that the VCO cna produce.

Other relationships such as VCO control voltage to frequency are often not linear.