Optimum transit angles of millimeter-wave Si IMPATT diodes
Optimum transit angles for maximum output power in the millimeter-wave IMPATT diodes are calculated analytically by considering the carrier diffusion process through the space-charge region. It is found that the optimum transit angle decreases, as the space-charge layer width reduces. The theoretical results show satisfactory agreement with the previously published experimental results for Si p+-n-n+abrupt junction diodes.
Theory of the mm Wave IMPATT Diode: A Review
Due to revived interest in mm wave technology, a lot of research work is going on, on the theoretical, experimental and technological innovation on mm wave Impatt diode. In this review, a search is made on the available theories on mm wave Impatt diode which helps in understanding the experimental results and also gives a physical insight to the device operation. Drift-diffusion model, MITATT mode operation, velocity-energy transport equation are the few tested so far. Sometimes, closed form solution does not give a good agreement with experiment and hence computer simulation is applied. Energy-momentum simulation for GaAs mm wave Impatt gives a better agreement with experiment compared to drift-diffusion model. However, for Si mm wave Impatt even simulation with conventional Impatt equations are good enough for experimental verification.
Batch fabrication of integral-heat-sink IMPATT diodes
A new technique for IMPATT-diode fabrication is described, in which the critical portion of the diode heat-flow path is formed as an integral part of the diode. The technique has economic advantages over conventional methods in that all processing steps are performed while diodes are still in wafer form. In addition, the technique permits passivation using standard dielectric deposition techniques, and the diode geometrical shape is such as to suppress premature edge breakdown. Typical experimental results are shown.