The relation of VCO gain and the noise of VCO tuning voltage

[hrkhari]

vco gain

I would appreciate if you guys could comment on the statement below in detail. Thanks in advance

Statement:
A high VCO gain results in high sensitivity to the noise of VCO tuning voltage, which increases the spur level and degrades the phase noise.

Rgds

 

[toonafishy]

Re: VCO Gain

VCO gain is stated in MHz/volt. So if the VCO changes 10 MHz for 2 volt change on the tuning line, the gain is 5MHz/V. The higher this gain, the more sensitive the tuning line is to any interference. Interference on the tuning line translates to unwanted FM on the VCO output.