Can unstable circuits with right-side poles exhibit resonant frequencies?

[EvLer]

Can a circuit that has transfer function with poles in right-hand side part of the imaginary-real plane (unstable system) have resonant frequency?

 

[berkeman]

Can a circuit that has transfer function with poles in right-hand side part of the imaginary-real plane (unstable system) have resonant frequency?

Sure. Several of my circuit designs had a resonant frequency that they kept wanting to find... :-)

 

[SGT]

Can a circuit that has transfer function with poles in right-hand side part of the imaginary-real plane (unstable system) have resonant frequency?

No passive circuit can have poles in the RHP. An active circuit can have them and the output (assuming second order behavior) will be:
ke^{\alpha t}cos(\omega_g t + \phi), where \omega_g[\tex] is the resonant frequency.<br /> Theoretically this circuit will produce oscillations in the frequency \omega_g[\tex] with amplitude growing to infinity.&lt;br /&gt; In a real circuit, when the amplitude grows, non linearities arise and the circuit will oscillate with fixed amplitude. Only we would not have a sinusoid anymore, but a distorted waveform, whose fundamental frequency is \omega_g[\tex] .&amp;lt;br /&amp;gt; &amp;lt;br /&amp;gt; I don´t understand why LaTex has not generated the correct image.