An oscillator circuit and
system are provided having a peak
detector that can determine a peak
voltage value from the oscillator. The peak
voltage value can then be compared against a predetermined
voltage value by a controller coupled to the peak
detector. The comparison value is then used to change a bias
signal if the peak voltage value is dissimilar from the predetermined voltage value. A
variable capacitor or varactor can be formed from a
transistor and is coupled to the oscillator for receiving the bias
signal upon a varactor bias node. The bias
signal is used to regulate the
capacitance within the varactor as applied to the oscillator nodes. Another controller can also be coupled to the peak
detector to produce a second bias signal if the peak voltage is dissimilar from a second predetermined voltage value. The second bias signal can then be forwarded into an
amplifier having a variable
gain to regulate the
gain applied to the oscillator. The combination of a varactor and
variable gain amplifier regulate the
negative resistance applied to the resonating circuit during startup and
steady state operations to ensure a relatively fast startup, and to maintain optimal loading and accurate
steady state amplitude after startup has completed.