Utilization and validation of HBT nonlinear frequency domain behavioral models in the design and simulation of oscillator circuits - P.J. Tasker; O. Mojón; M. Fernández Barciela; A. Rodríguez Testera; ALONSO MONTES, JOSE IGNACIO (European Microwave Week 2010, Eumw2010: Connecting The World, Conference Proceedings - European Microwave Conference, Eumc 2010, 2010)