|
 Ansoft Designer / Ansys Designer 在线帮助文档：
Nexxim Simulator >
Nexxim Harmonic Balance >
Harmonic Balance Technical Notes >
Controlling Nexxim Harmonic Balance Analysis >
Initial Guess for Vector of Node Voltages
Initial Guess for Vector of Node Voltages
The option initial_guess can be used to control
the initial guess for the vectors of node voltages and currents used
in the harmonic balance calculation.
Fewer Tones Initial Guess
initial_guess=fewer_tones is the default for
multi-tone analysis. For single-tone analysis, fewer_tones has
the same effect as initial_guess=dc (performs a DC analysis,
then starts harmonic balance with the DC values as the initial guess).
For multitone analyses, fewer_tones starts with the DC operating
point as the initial guess and solves the circuit with only the first
tone enabled. The values with the 1-tone analysis are used as the initial
guess for the analysis of the circuit with the first two tones enabled,
and so on until the circuit has been solved with all tones enabled.
For example, if the netlist contains:
.OPTIONS hb.initial_guess=fewer_tones
.HB tones=(1e6, 1.1e7, 2.1e7) maxk=(3,4,5)
The simulator first calculates the DC operating point,
then uses those values as the initial guess in solving the single-tone
analysis using tone 1e6Hz. The values from the 1-tone analysis then
become the initial guess for the two-tone analysis using tones 1e6Hz
and 1.1e7Hz. The result from the two-tone analysis then become the initial
guess for the full analysis using all three tones.
Fewer Tones Transient Initial Guess
initial_guess=fewer_tones_transient solves
the 1-tone problem using transient analysis, then proceeds to solve
the multitone problems with the fewer_tones algorithm described
above. This option has two subordinate options.
• initial_guess.fewer_tones_transient.tmax=val
sets the maximum step size. There is no default.
• initial_guess.fewer_tones_transient.tstop=val
specifies the stop time.
DC Initial Guess
initial_guess=dc performs a DC analysis, then
starts harmonic balance with the DC values as the initial guess. DC
is the default for single-tone analysis.
Zero Initial Guess
initial_guess=zero starts harmonic balance
with vectors of zero voltages and currents as the initial guess.
File Initial Guess
initial_guess=file uses vectors of node voltages
and currents saved from a previous harmonic balance simulation. When
file is the source for the initial guess, the netlist option
statement must also include an initial_guess_file=[pathname]filename
option to identify the file. The filename specifies the name
of an SDF-format file generated by a previous run of HB. The pathname
can be omitted if the file is in the directory where the netlist resides.
The pathname can
specify a subdirectory in the current directory; otherwise, the pathname
must provide the full directory path. See External Files in the Netlist
File Format help topic for details.
Note
|
The pathname
and filename of the initial guess file from a previous run of HB must
not be the same as the pathname and filename of the output file to be
generated by the current run of HB. That is, HB cannot read old values
from and write new values to the same file.
|
Transient Initial Guess
initial_guess=transient performs a transient
analysis, then uses the final values as the initial guess for the harmonic
balance analysis. When transient is the source for the initial
guess, the netlist option statement can also include two additional
options to control the transient analysis.
• initial_guess.transient.tmax=val
suggests a maximum step size to use.
• initial_guess.transient.tstop=val
sets the stop time.
Initial Guess in Sweeps
By default, harmonic balance applies the initial guess
strategy at the beginning of each iteration of a sweep. A separate option,
result_as_initial_guess, controls this behavior.
• result_as_initial_guess=0
turns off the use of previous results.
• result_as_initial_guess=1
enables the use of previous results. However, the use of previous results
is the default, so this option setting is never needed.
HFSS视频教程
ADS视频教程
CST视频教程
Ansoft Designer 中文教程
|
淘宝官方店 