i am trying to simulate colpitt oscillator in Proteus. the circuit is supposed to work for 100MHz. following is the schematic diagram. it is not working, i see only decreasing oscillating signal at the output.
i also doubt the value of C1 and C6 capacitor values, how are the value of these capacitors calculated?
the transistor was biased to give voltage gain of 10. Ic was taken as 10mA. running simulation shows no detectable current Ic and dc voltage across Vc point.
the transistor was biased to give voltage gain of 10. Ic was taken as 10mA. running simulation shows no detectable current Ic and dc voltage across Vc point.
SPICE simulator operation with Proteus may be a bit strange, but apart from this point the circuit is impossible to oscillate with the given LC values. They must be scaled by at least two orders of magnitude to get a reasonable resonator characteristic impedance Z0 = √L/C