A 24 GHz PHEMT-based oscillator

Presents a systematic nonlinear procedure for designing microwave oscillators utilising a nonlinear PHEMT model, the negative resistance approach and the describing function concept. The procedure is applied in the design of a 24 GHz oscillator which is then realised in hybrid technology. Measurement results show -6% shift in the frequency but an acceptable agreement in the output power. A detailed analysis shows that the frequency shift arises mainly from inadequate CAD models in the K-band, for the microstrip components employed in the design.