Monolithische GaAs FET- und HBT-Oszillatoren mit verbesserter Transistormodellierung (Volume 2) (English shop)

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This work deals with the analysis and optimization of monolithically integrated oscillators (MMIC-VCOs) on gallium arsenide (GaAs). The first part addresses the small-signal modelling of GaAs field-effect transistors (FETs) and heterojunction bipolar transistors (HBTs). A new algorithm for HBTs is presented that enables a reliable extraction of the elements of the small-signal equivalent circuit and has also been successfully applied to HBTs from other material systems (SiGe, InP). Furthermore, the low-frequency noise of GaAs HBTs is investigated and an extraction procedure for the relevant noise sources is developed. These results are then applied to the reflection oscillator, which is widely used in microwave engineering. The relationship between loop gain, loaded Q factor and phase noise is derived and analysed. This leads to a new design strategy with which the loaded Q factor can be maximized. On this basis, MMIC-VCOs at 38 GHz and 77 GHz were realized that achieve best-in-class values with respect to phase noise.