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A problem about oscillator and simulation software

叶少软件

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For the same amplification circuit,I simulated it in Multisim as normal,while ADS simulation only had fV level voltage,and the waveform was chaotic,not a normal sine wave.
I want to simulate a Clapp oscillator, where both Multisim and ADS only have parasitic oscillation(with a voltage gain of approximately 45.6 and a feedback coefficient of around 0.5).Is this a problem with the simulation software?If I build an actual circuit,will it generate oscillations?
(I want to generate a 7MHz oscillation,but there is only 28.3kHz parasitic oscillation in Multisim)

1689855987794.png
1689855935598.png
 
Circuit is incorrect.
The series tank does not resonate at 7MHz and is in the wrong place.
Google "Clapp oscillator circuit". There are plenty of examples and design formulae to guide you.
 
Many oscillators have an infinitesmal "stable point" which
DC solution -will- find, and then transient will merely
continue to solve (unless numerical noise suffices to kick it,
as thermal noise does in real life).

This is true of working oscillators, not just ones "stuck"
by a design fault or too-ideal / not-ideal-enough elements.

Inspect by applying a minuscule narrow current pulse at t=1n,
or a step in the voltage source, something to kick the core
off center so it will start circulating.
 

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