Slides Talk 10 4

IEEE Comm IEE ommun unic ication ations s Society Soci ety Portugal Portu gal Chapter Chapter Lisbon, IT, 22 March 2010

Int ntro rodu duct ctio ion n to t o antenn antenna a and ne nea arr-fi fie eld simu si mula lati tion on in CST Mic Micro rowa wave ve Stu Studi dio® o® software orge . os a Jerzy Guterman

© 2005, it - instituto de telecomunicações. Todos os direitos reservados.

CST Desi n Envi Environ ronme ment nt

Analysis and and design of static static and low frequency EM applications Simulation of free moving

high frequency problems Signal and power integrity and EMC/EMI analysis on printed

“Circuit tool” which combine simulators

Signal and power integrity and EMC/EMI analysis of cable harnesses

IEEE Communications Society Portugal Chapter

2

Lis bon , IT, IT, 22 March March 2010

CST MWS Simulation Method FIT: Finite Integration Technique Maxwell Equations ur uur E  ⋅ dl = −

∫

∂S

r

∫∫

ur uur D  ⋅ dS =

∫∫ ∂V

∂ B

uur ⋅ dS

uur uur H ⋅ dl

∫

∂S

S

∫∫∫ ρ dV

Maxwell Grid Equations r

⎛ ∂D r ⎞ uur = ∫∫ ⎜ + J ⎟ ⋅ dS

∫∫

S

Ce = −

ur uur B ⋅ dS = 0

b

% =q Sd

ur uur E  ⋅ dl = −

∫

∂S

Grid

Sb = 0

r

∫∫

∂ B

uur

⋅ dS

bn e j i

ei


Lis bon , IT, 22 March 2010

Ce = −

S

ek el

3

% = d d + j Ch

∂V

V

Calculation Domain

d

+ e j − ek − el = −

d dt

bn

d dt

b

⎡ ei ⎤ ⎢e ⎥ d j 1 1 −1 −1 ⎢ ⎥ = − 144244 3 ek dt ⎢ ⎥ C ⎣ el ⎦ {

e

b {

b

CST MWS Transient Solver

Material Equations r r D = ε E r r B = μ H r r uur J = σE + J s

d = M εe b = M μh

= M σe + js

Transient Solver hi +1 = hi ei + 3 2

= ei +

1 2

− Δt Mμ − Cei + % i+ − + Δt M − ⎡Ch 1

1

t

1 2

1

i +1

⎤


4


hi

ei +1 2

hi+1

ei + 3 2

CST MWS User Interface

Project type selection (environment parameters)

Navigation Tree Drawing Plane

Variables List


5


Project Messages Windows

1st Exam le: Di ole Antenna Initial Setup e ec new pro ec n 

Select “Antenna (Mobile Phone)” template



Confirm units



Confirm environment (air)


6


1st Exam le: Di ole Antenna Geometry Drawing Draw cylinder 

Name: “Arm_up”



Dimensions (in mm)



Material: Perfect Electric Conductor – “PEC”



Select object in nav ga on ree



Object transform


7


1st Exam le: Di ole Antenna Excitation and Simulation Setup Insert discrete port 

Setup frequency range



Run Transient Solver


8


1st Exam le: Di ole Antenna 1D Results n nav ga on ree go o 1D Results



o

Smith Chart

o

Port Signal

o

Energy

Can export results in txt file or


9


1st Exam le: Di ole Antenna Setting Monitors e on ors nav ga on tree + right mouse bottom): -

.

o

H-field @ 2.2 GHz

o

Farfield/RCS @ 2.2 GHz


10


1st Exam le: Di ole Antenna Improving simulation oun ary on Symmetry Planes

ons ->

=



o

XZ plane: magnetic (Ht=0)

o

XY plane: electric (Et=0)

Transient Solver o

Adaptive mesh refinement


11


1st Exam le: Di ole Antenna Adaptive mesh results n nav ga on ree go o Results -> Adaptive Meshing



o

Mesh cells

o

Solver time

Transient Solver Deselect “Adaptive mesh refinement” o

o

Press Apply


12


1st Exam le: Di ole Antenna Near-field results n nav ga on ree go o 3D Results -> E-field or H-field:

o

o



Amplitudes Phases

Can export results in txt


13


1st Exam le: Di ole Antenna Far-field results n nav ga on ree go o Farfields:



o

Co-pol. and Cross-pol.

o

Polar, 2D or 3D

o

Rad. Efficiency

o

Directivity or Gain

Can ex ort results in txt file or in GRASP format


14


1st Exam le: Di ole Antenna Structure Parameterization Select “Arm_up” in navigation tree 



Edit object



In define cylinder, change Zmax to variable “L”



Transient Solver o

o

Par. Sweep Add watch S11 in dB . New Par. “L”



Check & Start IEEE Communications Society Portugal Chapter

15


1st Exam le: Di ole Antenna Mesh Operations na e mes v ew 

View global mesh properties



Change local mesh of “Arm_up”


16


Visit CST Website www.cst.com


17


2nd Exam le: Microstri

Patch

Geometry Drawing



Draw “Ground”, “Substrate” and “Patch”



Define discrete port (use local coordinate system) e up requency range o & Field Monitors @ 2.2 GHz

Object

Xmin

Xmax

-

28 mm

11 mm

z

Ymin

Ymax

Zmin

-

Zmax

Material

.

Substrate

-40

40

-40

40

0.02

3

RT5880

Patch

-28

28

-21

21

3

3.02

Copper


18



Patch

Coaxial Feed (Part 1) 11



Macros -> Calculate -> Analytical Line Im edance



Draw “Inner Conductor” cylinder: o

o

e ec

roun

repea or

u s ra e

Object -> Boolean -> Insert -> “Inner ” Object

Radius

Zmin

Zmax

Inner Conductor

0.45

-20

3

Dielectric

1.49

-20

0

Outer Conductor

1.8

-20

0


19


Material Copper Teflon (

r

= 2.08)

Copper


Patch

Coaxial Feed (Part 2) “

”



Object -> Extrude -> create “Dielectric”



Repeat for “Outer Conductor”



Pick top face of “Dielectric”



Object -> Local Modifications -> Move Face (-3)



Re eat for “Outer Conductor”

1.04

Object

Radius

Zmin

Zmax

Inner Conductor

0.45

-20

3

Dielectric

1.49

-20

0

Outer Conductor

1.8

-20

0


20


Material Copper Teflon (

r

= 2.08)

Copper


Patch

Waveguide Port “

”



Select Waveguide Port






In navigation tree see 2D/3D Results -> Port o es



Compare S11 curves


21



Patch

Simulation of a body above antenna -

-



Copy S11 dB curve



Create brick of “Body”: o

Create new material “Body” εr = an σ= m






See S11 curve & radiation patterns


22


-70

70

-70

70

10

40

ues ons

...


23


Slides Talk 10 4

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