vco control node swinging

[yilmazerc]

hello
in my LC VCO the control node is swinging when there is a series resistance of the dc source which supplies the control voltage.

Do you think that shunting that node by a large capacitance solves this problem? Anyone who designed an LC VCO how did you overcome this problem?

Thanx

 

[uncle_urfi]

Shunting the node will bypass the high frequency noise from that node. Also, it will make the node more sluggish reducing Kv.
Control voltages are established using a current to voltage converter so that it is relatively immune to the problems such as the one you have mentioned.