A 3.0-6.5 GHz YIG-tuned transistor oscillator/amplifier

The availability of new microwave transistors with an fma, in excess of 11 GHz makes it feasible to design oscillator/amplifiers in the C-Band. region. The accurate highfrequency characterization of those transistors by their scattering matrix and the use of optimization methods account for best performance. High-Q single crystal ferrimagnetic garnets provide linear tuning and broadband coverage. Finally, hybrid thin-film techniques on high dielectric sapphire substrate keep the parasitic at a minimum and account for an optimum blend of the various elements.