Stability analysis of wideband linear bipolar varactor-controlled oscillator with two-coupled resonant circuits

Theoretical analysis of the stability conditions of the steady-state operat ion modes and tuning bandwidth characteristics of bipolar self-biased varac tor-controlled oscillator (VCO) with two-coupled resonant circuits are pres ented. The recommendations at the choice of the circuit and varactor parame ters for a linearization of the wideband tuning frequency characteristics u nder free-running stable oscillation conditions are given. Highly linear oc tave-band tuning operation was found to be possible using hyper-abrupt vara ctors in two-coupled resonant circuits VCO. Numerical and experimental resu lts verify the validity of the design approach described. (C) 1999 John Wil ey & Sons, Ltd.