Introduction to antenna and near-field simulation in CST Microwave Studio software

Transcription

1 Lisbon, IT, 22 March 2010 Introduction to antenna and near-field simulation in CST Microwave Studio software Jorge R. Costa Jerzy Guterman 2005, it - instituto de telecomunicações. Todos os direitos reservados.

2 CST Design Environment 3D EM simulation of high frequency problems Signal and power integrity and EMC/EMI analysis on printed circuit boards Analysis and design of static and low frequency EM applications Simulation of free moving charged particles Circuit tool which combine results from other CST simulators Signal and power integrity and EMC/EMI analysis of cable harnesses 2 Lisbon, IT, 22 March 2010

3 CST MWS Simulation Method FIT: Finite Integration Technique Maxwell Equations Maxwell Grid Equations r r ur uur B uur uur uur D r uur d d E dl = ds H dl = + J ds Ce = b Ch % = d + j t t dt dt ur uur ur uur Sd % = q Sb = 0 D ds = ρdv B ds = 0 S S S S V V V Calculation Domain Grid r ur uur B uur d E dl = ds Ce = b t dt t S S e k e l b e j n ei e e k C el { e d b dt { n b j e [ ] = [ n ] d e + e e e = b dt i i j k l n 3 Lisbon, IT, 22 March 2010

4 CST MWS Transient Solver Material Equations r r D=εE r r B = μ H r r uur J = σ E+ J s d= M e σ ε b= M h μ j = Me+ j s Transient Solver h = h Δt M Ce i+ 1 i 1 i+ 1 2 μ i+ 32 i i+ 1 i+ 1 = +Δt t % h i ε e e M Ch j i+1 2 e i+1 h i+3 2 e t 4 Lisbon, IT, 22 March 2010

5 CST MWS User Interface Project type selection (environment parameters) Navigation Tree Drawing Plane Variables List Project Messages Windows 5 Lisbon, IT, 22 March 2010

6 1 st Example: Dipole Antenna Initial Setup Select new project in CST MWS Select Antenna (Mobile Phone) template Confirm units Confirm environment (air) 6 Lisbon, IT, 22 March 2010

7 1 st Example: Dipole Antenna Geometry Drawing Draw cylinder Name: Arm_up Dimensions (in mm) Material: Perfect Electric Conductor PEC Select object in navigation tree Object transform 7 Lisbon, IT, 22 March 2010

8 1 st Example: Dipole Antenna Excitation and Simulation Setup Insert discrete port Setup frequency range Run Transient Solver 8 Lisbon, IT, 22 March 2010

9 1 st Example: Dipole Antenna 1D Results In navigation tree go to 1D Results o S 11 o Smith Chart o Port Signal o Energy Can export results in txt file or TOUCHSTONE format 9 Lisbon, IT, 22 March 2010

10 1 st Example: Dipole Antenna Setting Monitors AddFi Field ldmonitors (navigation tree + right mouse bottom): o E-field@22GHz 2.2 o 2.2 GHz o 2.2 GHz 10 Lisbon, IT, 22 March 2010

11 1 st Example: Dipole Antenna Improving simulation Boundary Conditions -> Symmetry Planes o YZ plane: magnetic (Ht=0) o XZ plane: magnetic (Ht=0) o XY plane: electric (Et=0) Transient Solver o Adaptive mesh refinement 11 Lisbon, IT, 22 March 2010

12 1 st Example: Dipole Antenna Adaptive mesh results In navigation tree go to 1D Results -> Adaptive Meshing o S 11 o Mesh cells o Solver time Transient Solver o Deselect Adaptive mesh refinement o Press Apply 12 Lisbon, IT, 22 March 2010

13 1 st Example: Dipole Antenna Near-field results In navigation tree go to 2D/ 3D Results -> E-field or H-field: o Field components o Amplitudes o Phases Can export results in txt file 13 Lisbon, IT, 22 March 2010

14 1 st Example: Dipole Antenna Far-field results In navigation tree go to Farfields: o Field components o Co-pol. and Cross-pol. o Polar, 2D or 3D o Rad. Efficiency o Directivity or Gain Can export results in txt file or in GRASP format 14 Lisbon, IT, 22 March 2010

15 1 st Example: Dipole Antenna Structure Parameterization Select Arm_up in navigation tree Edit object In define cylinder, change Zmax to variable L Transient Solver o Par. Sweep o Add watch S 11 in db o New Seq. & New Par. L Check & Start 15 Lisbon, IT, 22 March 2010

16 1 st Example: Dipole Antenna Mesh Operations Enable mesh view View global mesh properties Change local mesh of Arm_up 16 Lisbon, IT, 22 March 2010

17 Visit CST Website 17 Lisbon, IT, 22 March 2010

18 2 nd Example: Microstrip Patch Geometry Drawing New Project Draw Ground, Substrate and Patch Define discrete port (use local coordinate system) Setup frequency range (1to 3GH GHz) & Field 2.2 GHz Run transient solver 28 mm 11 mm Object Xmin Xmax Ymin Ymax Zmin Zmax Material Ground Copper Substrate RT5880 Patch Copper 18 Lisbon, IT, 22 March 2010

19 2 nd Example: Microstrip Patch Coaxial Feed (Part 1) Copy S 11 db curve & delete discrete port Macros -> Calculate -> Analytical Line Impedance Draw Inner Conductor cylinder: o Select t Ground d ( (repeat tf for Substrate ) t o Object -> Boolean -> Insert -> Inner Conductor Object Radius Zmin Zmax Material Inner Conductor Copper Dielectric Teflon (ε r = 2.08) Outer Conductor Copper 19 Lisbon, IT, 22 March 2010

20 2 nd Example: Microstrip Patch Coaxial Feed (Part 2) Pick lateral face of Inner Conductor Object -> Extrude -> create Dielectric 1.04 Repeat for Outer Conductor Pick top face of Dielectric Object -> Local Modifications -> Move Face (-3) Repeat for Outer Conductor Object Radius Zmin Zmax Material Inner Conductor Copper Dielectric Teflon (ε r = 2.08) Outer Conductor Copper 20 Lisbon, IT, 22 March 2010

21 2 nd Example: Microstrip Patch Waveguide Port Pick bottom face of Outer Conductor Select Waveguide Port Run Transient Solver In navigation tree see 2D/3D Results -> Port Modes Compare S 11 curves 21 Lisbon, IT, 22 March 2010

22 2 nd Example: Microstrip Patch Simulation of a body above antenna Copy E- and H-planes radiation patterns Copy S 11 db curve Create brick of Body : o Create new material Body ε r =5 and σ=1 1(S/ (S/m) Run Transient Solver See S 11 curve & radiation patterns 22 Lisbon, IT, 22 March 2010

23 Questions? After a CST simulation Lisbon, IT, 22 March 2010