A modified MODPEX model for MOSFET and parameter optimization using excel-based genetic algorithm
MODPEX is widely used in industry and universities to produce Pspice model for power semiconductor devices, including MOSFETs. However, the model generated by MODPEX for MOSFETs does not include channel charge at strong inversion condition. This paper presents a modified MODPEX model for MOSFETs, which includes channel charge at strong inversion condition. A process based on genetic algorithm (GA) implemented in Microsoft Office Excel is developed to optimize parameters of the modified MODPEX model. Static and dynamic validation proves that the modified MODPEX model improves simulation accuracy in both switching loss and driver loss.
Application of the Genetic Algorithm in MOSFET Modeling and Parameter Extraction
In this paper, the genetic algorithm is introduced into parameter optimization for MOSFET small-signal model parameter extraction for up to 60 GHz millimeter-wave operations. Initial parameters of the model are extracted by curve fitting and direct parameter extraction method in saturation region approximately, and then fourteen independent parameters of the equivalent circuit model are optimized together. The real and imaginary part of S-parameter are set as the fitting targets simultaneously in this study. With the more convenient genetic algorithm, the model with the optimized parameters gives a better fitting accuracy than the initial parameters without optimization.
Flow in a branching open channel: a review
Branching channel flow refers to any side water withdrawals from rivers or main channels. Branching channels have wide application in many practical projects, such as irrigation and drainage network systems, water and waste water treatment plants, and many water resources projects. In the last decades, extensive theoretical and experimental investigations of the branching open channels have been carried out to understand the characteristics of this branching flow, varying from case studies to theoretical and experimental investigations. The objectives of this paper are to review and summarise the relevant literatures regarding branching channel flow. These literatures were reviewed based on flow characteristics, physical characteristics, and modeling of the branching flow. Investigations of the flow into branching channel show that the branching discharge depends on many interlinked parameters. It increases with the decreasing of the main channel flow velocity and Froude number at the upstream of the branch channel junction. Also it increases with the increasing of the branch channel bed slope. In subcritical flow, water depth in the branch channel is always lower than the main channel water depth. The flow diversion to the branch channel leads to an increase of water depth at the downstream of the main channel. From the review, it is important to highlight that most of the study concentrated on flow characteristics in a right angle branch channel with a rigid boundary. Investigations on different branching angles with movable bed have still to be explored.