Heterojunction cathode contact transferred-electron oscillators

The influence of forward and reverse biasing of isotype heterojunction cathode contacts on the operating mode of millimeter-wave transferred electron devices (TEDs) is analyzed. The GaAlAs/GaAs cathode contact is utilized as the forward model and GaInAsP/InP contact cathode is the reverse model for this experiment; the two models are applied to a 100-GHz TED. The results reveal that forward-biased cathode contact TEDs operate in a fundamental accumulation-layer transit time mode and display RF performance very close to n(+)-n-n+ GaAs fundamental devices; reversed-biased cathode contact TEDs operate in an overlength dipolar layers mode and exhibit RF conversion efficiency levels twice as high as those for n(+)-n-n+ InP fundamental devices.