Effects of ionization rates on IMPATT device admittance

The significance of using different ionization rates on the operating characteristics of Si IMPATT devices is examined. The dc breakdown and small-signal results of IMPATT devices at room temperature are presented. Numerical results for p⁺nn⁺as well as the complementary n⁺pp⁺Si diodes in the millimeter-wave frequency range and at different current densities ranging from 2500 to 10 000 A/cm²are given. It is shown that large differences in some important device parameters are obtained, depending on the ionization rates employed.