HB analysis of injection locked oscillators using commercial CAD tools

In this paper a new technique is proposed for the analysis of injection locked oscillators on the basis of commercially available HB-based CAD tools for communication circuits. The proposed methodology does not require either direct access to the HB simulation engine or application of auxiliary components to the circuit topology. The HB convergence in the presence of a particular injected signal, having assigned frequency and power characteristics, is simply obtained by suitably providing the simulator with a proper initial guess of the unknown circuit solution through the standard HB user interface in the Agilent ADS software. Accurate prediction of the output phase shift for each injected frequency and estimation of the locking range are easily achieved. The proposed technique is validated through accurate comparisons with simulations carried out in the time domain.