Experimental characterization and compact modeling of microwave injection-locked pulsed oscillators

The problem of predicting, by computer-aided means, the complex phenomena observable in the dynamic response of microwave injection-locked pulsed-oscillators (ILPO) under both continuous-wave and modulated input signal drive is addressed. The proposed method makes use of characterization data taken on ILPO under both short- and long-pulse (or non-pulsed) sinusoidal operation in order to derive a nonlinear differential model in the stroboscopic time domain capable of describing the behaviour of the injection-locked oscillator under all operating conditions, including the undriven one with its associated intra-pulse amplitude and frequency variation (chirp). The experimental verification results presented show that the proposed characterization and modeling approach not only reduces the complexity of the model identification phase with respect to standard, equivalent-circuit based, methods, but also permits one to couple an excellent computational efficiency to a reasonably good simulation accuracy in predicting the ILPO response to real-world input signals.