Rana Aly Onsy
Newbie level 2
Hi all
Does an LC VCO schematic contain a pulse generator with a very large period (can be placed in series with one of the capacitors) just as a source for noise to help start oscillation?? My LC VCO only works in this case but it doesn't work on removing the pulse generator, is this correct??
Also, there is something I can't understand, I designed the vco (haven't yet placed varactors) so that the C & L values gives a frequency of 0.5GHZ, but on carrying out the simulation, the frequency is found to be 2.5GHZ, why??
Should there be any resistance placed in parallel with the tank circuit?? is the Rp which is always mentioned in any article concerning this point just a theoritical issue, relating the coil and cap. internal resistances and gm of the Mosfets to the design??.
I don't know how to use the resistance from the technology files, it refuses to change its values, and the values already placed are very small, about 90mohm
Thanks in advance for any offered help.
Does an LC VCO schematic contain a pulse generator with a very large period (can be placed in series with one of the capacitors) just as a source for noise to help start oscillation?? My LC VCO only works in this case but it doesn't work on removing the pulse generator, is this correct??
Also, there is something I can't understand, I designed the vco (haven't yet placed varactors) so that the C & L values gives a frequency of 0.5GHZ, but on carrying out the simulation, the frequency is found to be 2.5GHZ, why??
Should there be any resistance placed in parallel with the tank circuit?? is the Rp which is always mentioned in any article concerning this point just a theoritical issue, relating the coil and cap. internal resistances and gm of the Mosfets to the design??.
I don't know how to use the resistance from the technology files, it refuses to change its values, and the values already placed are very small, about 90mohm
Thanks in advance for any offered help.
