A moving boundary diffusion model for PIN diodes

AlGaAs Anode Heterojunction PIN Diodes

This paper describes the development of a heterojunction AlGaAs/GaAs PIN diode as a revolutionary improvement as compared to the homojunction GaAs PIN diode commonly used in microwave systems for commercial and military applications. In a heterojunction device the injected carriers from the junction are confined by the bandgap discontinuity between the AlGaAs/GaAs layers. This confinement effec...

Moving Boundary Problems with Nonlinear Diffusion

Moving boundary problems governed by anomalous diffusion.

Anomalous diffusion can be characterized by a mean-squared displacement 〈x(2)(t)〉 that is proportional to t(α) where α≠1. A class of one-dimensional moving boundary problems is investigated that involves one or more regions governed by anomalous diffusion, specifically subdiffusion (α<1). A novel numerical method is developed to handle the moving interface as well as the singular history kernel...

A moving boundary model of acrosomal elongation

A sperm penetrates an egg by extending a long, actin-filled tube known as the acrosomal process. This simple example of biomotility is one of the most dramatic. In Thyone, a 90 I~m process can extend in less than 10 s. Experiments have shown that actin monomers stored in the base of the sperm are transported to the growing tip of the acrosomai process where they add to the ends of the existing ...

A SPICE model for simulating the impedance-frequency characteristics of high frequency PIN switching diodes

A SPICE model for the microwave and RF PIN switching diode is presented. The model simulates the important Iregion charge storage phenomenon and its effect on the PIN diode impedance-frequency characteristic. The SPICE model is described and validated by comparisons with both analytical and measured results.