Timestep Control — Ansoft Designer 7.0 在线帮助文档，Ansys Designer 教程

淘宝官方店推荐课程在线工具联系方式关于我们

	微波射频仿真设计 Ansoft Designer 中文培训教程 \| HFSS视频培训教程套装
	Agilent ADS 视频培训教程 \| CST微波工作室视频教程 \| AWR Microwave Office

Timestep Control

Transient analysis uses a variable timestep that depends on several factors:

• Failure of the Newton-Raphson iterations to converge.

• The Local Truncation Error and the Local Error.

• The rmax and delmax options, which control the maximum timestep size.

• The trtol option, which controls the relative solution tolerance.

If the Newton-Raphson iterations on any timestep fail to converge, the simulator decreases the size of the timestep and tries again.

If the Local Error (which is calculated based on the Local Truncation Error) on any timestep is too large, the simulator decreases the size of the timestep and tries again.

The rmax and delmax options control the maximum size of the timestep. In general, the maximum timestep is the minimum of the following two values:

• The value of the delmax option, if one has been assigned.

• The value calculated by multiplying the value of the rmax option (default 10) times the tstep argument from the .TRAN statement and incorporating circuit information such as input frequencies.

The trtol option specifies the (dimensionless) ratio between the tolerance of the overall transient analysis solution and the tolerance used in the Newton-Raphson iterations. The default of seven (7) means that tolerance used for the transient analysis solution is seven times looser than the tolerance used for the Newton-Raphson iterations. Increasing trtol has the effect of decreasing solution accuracy and increasing the timesteps.

Note

Nexxim does not use the HSPICE “NPDELAY” parameter when it is present in imported netlists. Nexxim’s timestep methodology is more advanced than HSPICE’s NPDELAY method.


Copyright © 2006 - 2013 微波EDA网, All Rights Reserved 业务联系：mweda@163.com