A wide FET structure is considered as a voltage controlled directional coupler. A model for the device has been developed taking into account its distributed nature. The variation with bias of the source-drain S-parameters is presented and the model compares very well with measured results up to 20 GHz. The results show large variations in forward coupling from source to drain. The model has been used to investigate the effects of different gate terminations. Improved performance was then predicted and obtained, with 50 ω loads. For this case the gate associated S-parameters are also presented.
ASJC Scopus subject areas
- Electrical and Electronic Engineering