Hello,

I am simulating a quadrature L-C VCO. There should be two stable states in this oscillator, one oscillates at higher frequency and the other at lower frequency.
For example, for about 2.4GHz QVCO, it has equal possibility to oscillate at 2.5GHz or 2.3GHz.

But in my simulation, It only oscillates at the higher frequency 2.5GHz, and couldn't oscillate at the lower frequency 2.3GHz. It must be two states because this QVCO appears two oscillation states in the real product test.

How to initialize or vary the parameters of this QVCO? so I could find the other oscillation state in simulation (HSPICE).

Thanks!