Computer study of optimum millimeter-wave conductance of GaAs and Si double drift impatt diodes for flat and low-high- low structures

摘要

A comparative study of dc and small signal characteristics of GaAs and Si double drift (flat and low-high-low) structures operating in the 28-56 GHz frequency band has been carried out keeping both the total depletion layer width as well as the dc bias current constant. The results show that the upward shift in operating frequency due to incorporation of impurity bumps is more in case of GaAs diodes than for Si diodes. The optimum value of high frequency negative conductance is larger for Si DDR compared to GaAs. Also the increase in magnitude of the negative conductance is larger for Si DDR compared to its GaAs counterpart when the structure changes from flat to low-high-low (LHL).