Approach to the design of transmission-type injection-locked microwave oscillators through behavioral block modeling

In this work, an attempt is made toward the development of a systematic design method for the performance-driven dimensioning of the various elements comprising the structure of modern transistor-based microwave injection-locked oscillators with transmission-type topologies (TILOs). The proposed approach is based on the use of appropriate diakoptics of the various circuit blocks into a matched environment, and their behavioral modeling in the fundamental-frequency dynamical complex envelope domain with the help of standard circuit and E.M. simulation CAD tools. This will permit, in the end, to obtain closed-form expressions for the main TILO performances in terms of the design parameters, thus permitting their optimization as a function of system-level specifications. The practical validity of the method developed was tested by designing and building a single transistor 10.75GHz core-TILO with a wide locking bandwidth (>4MHz) at the low nominal input power level targeted (−20dBm).