Non-linear design, optimization and analysis of an injection-locked high efficiency VCO with arbitrarily width modulated microstrip line networks

In this work a non-linear efficiency optimization method for its application to a high efficiency Voltage Controlled Oscillator is presented. The technique is founded on the use of an auxiliary generator and several multi-harmonic loads based on Arbitrarily Width-Modulated Microstrip Lines to ensure the convergence of the optimization process. A 2.5 GHz high efficiency VCO has been designed and synchronized with an external signal. Then, a detailed analysis of the efficiency of all the possible synchronized solutions of the injection locked VCO is presented. Finally, to validate the technique, a prototype has been implemented and experimentally characterized, obtaining a good agreement between the simulated and measured results.