【实例简介】
详细介绍周期性结构的色散曲线仿真，基于CST，但HFSS设置基本相同
smr.razavizadeh @ieee.org
Dispersion diagram: CST Microwave Studio
flow and Pierce Impedance can be seen in the folder ID Resulls In parameter sweep window,
select"Edit" to view or modify the source code
taex0e-red wacc 0r parameter sweep
He, inrTtring
Result match
二he水
A-c result of a perameter sweep of the rhese between the periodic bourdery-wall.
:: pOwer =l0w, axa. electIc -LEld amol1-ud
Start
It ig recommeded to perform a aweer with phaae atena
tEgel
New seg.
Dete
Fig. 5 the user-defined vba codes of the important reports of the simulation as dispersion
curve, phase group velocity and pierce impedance
But I preferred that the following method for setting the dispersion diagram
Post processing:
The dispersion diagram, which is a graph based on"frequency"VS spatial phase variations of
the predefined parameter of phase", could obtained by the following step by step process
1)Recall the tbp and choose the 2D and 3D Field Results>3D Eigenmode result
学[p水P中n
Temp ate Based Postprocessing
General Resuts
Geneal Res Its
30FmR(3)
aD and 2) Fald Souto
Result Temo
Manage
Ac 3n FigenmxdrR
Resut name
Type Template nane
Fequency
equency Mode
alare Integation R mge
00
A Eval=Le A
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crider o :r y icty bexa-lnotused
Setings. DeeteCuplcate Evauace i Daete Al EralLate All
Lancel Hap
Lotte.
□oco9Hp
Fig. 6 the outline of defining the postprocessing setup of dispersion plot in CSt
MWS
2) For obtaining the dispersion data of the modes start one by one from the first mode, then
after finishing simulation operation export the data in"Lxi format(available in "Table
folder in Navigation tree) for our future postprocessing in Matlab environment
3)Evaluate
Solver Setup
Whenever the Eigenmode Solveris started, a specific number of the lowest resonance
frequencies of the structure are calculated. Since only the fundamental mode is of interest, the
number of modes is reduced to"I'", and the JDM eigenmode solver is chosen, which is faster for
e given cxample
smr. razavizadeh @ieee. org
Dispersion diagram: CST Microwave Studio
上 enmod= Solver parameters
Mesh type(1) Hexahedral mesh
JDM
Choose number of modes
tomatically(0….1CG2)
o Frequencies above
Simplify Model.
F Store all result data in cache
F Calculate externa Q-facior
□ Consider
Adaptive mesh refinement
D Adaptive meshrefinement Properties
Fig 7 Eigenmode Solver setting for calculating the dispersion characteristics of the proposed
periodic structure
After the parameter sweep has been selected from the Eigenmode Solver's dialog, a new
sequence is added, and the parameter "phase" is chosen to be swept from 0 to 180 degrees in 19
steps for an equal ster
daimler
Sequences
Result wach
Check
-l sequence 1
Userdefined
Start
Parameter Sweep Paramete
Resi lt TemplatE
Name:pnase
Acceration,u.
V SwEep
180
ew Par. Edit…
Fig 8 Parametric sweep setup for pha
parameter of"pha
the
Start.
If you set lower sweep limit at zero, the machine temporary would interrupt the process and
alert we the parameter is zero, dont care about it and click Ok to continue the operation
≈
rometer Phese
Fig10
4
smr.razavizadeh @ieee.org
Dispersion diagram: CST Microwave Studio
Results
During the run process the real time dispersion results is accessible from the Table folder, as
plot based on frequency vs phase parameter, as following
Freyuellcy(Mude 1)
A Anchor Pants
F Excitaior Signas
0
4k Volage and Curer Monitors
20
I Mash Corro
ldse
Tables(or Results \Frequency(Mode 1) Parameter View Kjh
LA 2D/3D R:suts
层 TLM Res_ts
Paraneter LIst
I:/value Descrnigtid Tvpe
helix2cst
8 numbe of None
回68%
A Fequercv Mede 1)
Leng.h
Eigenmode Aralysis Solver setup ( /21
Langh
9%[x[n画
Undefined
冫hei2*
Propagation Cons ant beza/m
路凵 unwed Veneris
Mode 1
Votage and Cument Monit=rs
0.511.522.533.544.555.5
SD Schenafc 1D Result Dispersion Dagan Wode 1x Parameter View Bs
N:Value Deaciotiof Trpe-Reheixzct
修 TLM Resuts
回7%区x
s Table
phaee.50 phase ahM None
igenmoce Analysis: Salver setup(2/2.
Fmquenry Moda 1)
9%×[町A31
Undcfndd
essages Progress
Fig. ll The dispersion diagram based on(a) TBP result template, and (b)vba
userdefined
As shown in Fig. Il, all the data are the same but in Fig. I l(a) the horizontal axis is the phase
Export the data of the mode "1
ResH Yev
1) Plot Praperties.
Pbt type:
Abscissa
Crve set parameter:
Table Properties
ProPerties.
Parameter
sele-ted vaue
Copy vicwto Clipbord
Copy
Ctrl+C
E TLN Fests
OBject nformation
E Apy Haaieiei scluys lu all LumiA iLle abl=s
U29pupu烂
ADot CanceSmthchart.Ccrcex. To Currert
smr. razavizadeh @ieee. org
Dispersion diagram: CST Microwave Studio
S Export Plot Data
varc n.
OIL H
File rame.
Save
Save as type: Datatiles(ht)
Cancel
Model
Fig. 12 extraction of table dispersion data
Open via excel
Open a new Excel file and open from it your txt file of"Model. txt:
一
Import Wirord deploy
The Text wizard has detemned thet your deta is Fxee width
If tr s is conect. choose Nect, cr coos the data t/pa that best desaias you data
ECpe
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t Libres
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startimortat row:1 a Fle ncn: 437: CE4Jntad states
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smr. razavizadeh @ieee. org
Dispersion diagram: CST Microwave Studio
py cr the
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save as type
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lags Add a tag
box to selct trom
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Fig, 13 The preparation of the dispersion text data file for producing the
compatible * .csv file
We should keep just the phase and value column and eliminate others, then edit the title of the
value column as Frequency(Model), finally save as a Csv file format, as shown in Fig. 13. We
should repeat the simulation for remained modes frequencies as presented in Fig. 14, and extract
the favorite data for updating the previous"model. csv?"data file
Reault woth
Solve se: tings
Template Based Postprocessing
Method: DM
dAnd 3D Rel beans
Modes
velAte.
thoose number of modes
automatically (Dm 10 CHe
Resa nere (2)
Resut aus.
Adaotive mesh refirement
(3)
Volage Integretion nange
Setings Delete Dupicae Evaluate 0B[
Sensitity amalysis
口 Lse sensivity anays Prcoertes
ICK [Cancel][Help CRawPore Logie
Fig. 15 How we can update the calculation for the higher mode
Lumet
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Frequency( Model) Frequen y Mode2) Frequency mode) Frecuency Mod
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Fig. 16 all the dispersion data gathered in one csv file for plotting the final
dispersion diagram for first forth modes of the proposed 1 D-periodic structure
smr. razavizadeh @ieee. org
Dispersion diagram: CST Microwave Studio
Mtalab Code for plotting the dispersion diagram
For publishing all of your plot result, especially in ieEE publications, we should import our
data into matlab environment, as a perfect engineering tool to sketch various plots in a unique plot
in a high resolution view. Here we present a brief quick guide about it
IRun matlab
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2)import the dispersion csv file
Lock in: Sow Wave
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4)disable the header and text box
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o Create variables matching preview
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O Create vectors from each co l m n uan g column
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o Create vectors ftom each row using aw names
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)Run the plot m file(see the appendix)
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smr.razavizadeh @ieee.org
Dispersion diagram: CST Microwave Studio
na resu
20
Mode 1
18
Mode2
16
Mode3
下14
Mode4
TE
12
10
BAND GAP
LL 6
RL
20406080100120140160180
Phase(Deg
Fig. the final sketch of the dispersion diagram obtained by a matlab plotting
program(Appendix)
smr. razavizadeh @ieee. org
Dispersion diagram: CST Microwave Studio
Example2 2D-periodic structure dispersion diagram
In this section, dispersion characterization of surface waves propagating on a mushroom-like
periodic structure is investigated using CST MWS
Mushroom-like Ebg structures
Wavenumber k is an important parameter to describe the propagation property of
electromagnetic waves In a lossless case, the phase constant is B=k
Usually, B is a function of frequency o. Once the phase constant is obtained, the phase velocity
(vp) and group velocity(vg) can be derived
nd v
dB
Furthermore. the field distribution can also be determined such as the field variation in a
transverse direction. For a plane wave in free space, the relation between B and w is a linear
function
6(0)=k=0yoE
(2-2)
For surface waves propagating in an EBG structure, it is usually difficult to give an explicit
expression for the wavenumber k. One has to either solve an eigen-value equation or perform a full
wave simulation to determine the wavenumber. It is important to point out that the solution of an
eigen-value equation may not be unique.
In another words, there may exist several different propagation constants at the same
frequency. Each one is known as a specific mode with its own phase velocity, group velocity, and
field distribution. The relation between B and o is often plotted out and referred to as the
dispersion diagram
For a periodic structure such as the EBG, the field distribution of a surface wave is also
periodic with a proper phase delay determined by the wavenumber k (orB) and periodicity p
Thus, each surface wave mode can be decomposed into an infinite series of space harmonic waves
E(x,y,)=∑+(y,2)e-1nx,月n(a)=B2(a)+n
Here, we assume the periodic and propagation direction is the x direction. Although these space
harmonics have different phase velocities, they share the same group velocity. Furthermore, these
space harmonics cannot exist individually because each single harmonic does not satisfy the
boundary conditions of the periodic structure. Only their summation satisfies the boundary
conditions. Thus, they are considered to be the same mode
【实例截图】
【核心代码】