I want to build a oscillator that operates

I have tried various combinations of L and C, but I cannot. What should I do?

 

Welcome to AAC.

How did you choose that various values of L and C?

 

Welcome to AAC.

How did you choose that various values of L and C?

I'm currently attempting different approaches, but I'm unsure how to determine the values I need.

 

hi ang,
Is this a simulation circuit or an actual component circuit you are testing.?
E

 

hi ang,
Is this a simulation circuit or an actual component circuit you are testing.?
E

its simulation circuit !

 

I'm currently attempting different approaches, but I'm unsure how to determine the values I need.

Do you know the criterion for oscillation?
Did you simulate the loop gain at first?

 

I want to build a Colpitts oscillator that operates at 100MHz.
I have tried various combinations of L and C, but I cannot achieve 100MHz

105 MHz:
___

 

105 MHz:
View attachment 295561 ___View attachment 295637

Thanks!
how to calculate Q factor ?

 

how to calculate Q factor ?

Q = Pstored/Pdissipated = I2X/I2R Q = X/R where:
X = Capacitive or Inductive reactance at resonance
R = Series resistance.
This formula is applicable to series resonant circuits,
and also parallel resonant circuits
if the resistance is in series with the inductor.

ADDED: https://www.physics.utoronto.ca/~phy224_324/experiments/q-oscillators/Qoscilla.pdf

 

105 MHz:
___View attachment 295637

I'm unable to achieve oscillation, let alone obtain a frequency with your circuit. What should I do to address this issue
and Should the Q factor be considered when determining the values of L and C ? .. TT Plz

 

I'm unable to achieve oscillation, let alone obtain a frequency of 100MHz with your circuit

Q factor? May be. So what is resistance of your coil? Mine is 1 mΩ.

But my circuit does not work
with such (your) configuration: _____________________This is working:

______________

ADDED: With and without C5
____________

 

I'm unable to achieve oscillation, let alone obtain a frequency of 100MHz with your circuit. What should I do to address this issue
and Should the Q factor be considered when determining the values of L and C ? .. TT Plz

No, the Q-factor of the coil is less important.
Basic rule: When an oscillator circuit does not work, you must check the oscillation condition by displaying the loop gain (Magnitude and phase) - as I have recommendd already in post#6.
Anything else is "try and error (and hope)".