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

首页 >> Ansoft Designer >> Ansoft Designer在线帮助文档

Ansoft Designer / Ansys Designer 在线帮助文档：

Nexxim Simulator >
Nexxim Harmonic Balance >
   Harmonic Balance Technical Notes >
       Controlling Nexxim Harmonic Balance Analysis >
           Increasing Accuracy or Speed

Increasing Accuracy or Speed

The HB statement parameters auto_refine_solution and trim_tol direct the simulator to automatically adjust the number of harmonics during the simulation to provide either increased accuracy (more harmonics) or faster simulation (fewer harmonics).

The auto_refine_solution Statement Parameter

When the simulation includes a sweep of power, accuracy can be improved by increasing the number of harmonics as power increases. The auto_refine_solution option increases the harmonics as needed. The syntax for this statement parameter is:

auto_refine_solution=no|yes

The default is no, specifying that no automatic increase is to be done.

With auto_refine_solution=yes, Nexxim examines the result at each sweep iteration to determine if the solution is sufficiently resolved. If it is not, Nexxim doubles the number of harmonics and repeats the iteration. Thus, you can start the sweep with MAXK set to a low number, and have Nexxim automatically increase MAXK as needed to maintain accuracy. Example:

.HB TONES=(1.01e6,2.7e6) MAXK=(3,7) AUTO_REFINE_SOLUTION=YES
+ SWEEP pwr_val START=1.5 STOP=2.5 STEP=0.5

The trim_tol Statement Parameter

IP3 analyses and similar N-tone problems with N>2 may not require the full tensor product using all the harmonics of all the tones. To increase the speed of the analysis, it is useful to “prune” harmonics that have minimal contribution. The trim_tol parameter in the HB statement causes Nexxim to prune harmonics automatically after the initial guess calculation. The syntax is:

trim_tol=val

The default value is 0.0, specifying that no pruning is to be done.

The parameter trim_tol is a voltage tolerance like abstol. The tolerance is applied to the harmonics calculated in the two-tone initial guess. Setting trim_tol to a value such as 1e-6 directs Nexxim to eliminate any harmonic whose coefficient has magnitude less than 1e-6. The pruning is then symmetrically applied to higher tones so that the result has fewer frequencies than the full tensor product.

With the trim_tol parameter, you can start out with large MAXK values for each of the HB TONES frequencies. This is equivalent to oversampling the frequencies. The trim_tol parameter directs Nexxim to prune the harmonics in a way that depends on the circuit specifics. This parameter allows you to avoid trying to determine the optimal MAXK values in advance. Example:

.HB TONES=(1.01e6,2.7e6,3.221e6) MAXK=(21,21,21) TRIM_TOL=1e-6

HFSS视频教程 ADS视频教程 CST视频教程 Ansoft Designer 中文教程


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