designing of single ended vco

hi all,

I find few papers about VCO design using single transistor for the frequency at several GHz. Is anyone know the reason? for colpitts structure, is it suitable for 3-10 GHz design?

many thanks!

i think always everyone design the VCO to be differential , coz it will be integrated thus the differential signals will be ok ,

the cross coupled pair is very easy

khouly

i want a single output.

using differential structure is not difficult but after that LC network is needed to combine the differential outputs which decreases the output power because of the poor Q.

That is the reason for using sinlge-ended VCO.

Thanks

oh u used differential VCO and then transformed it to single ended .

try to used collpits topology , but i haven't seen ppl do it

khouly