微波无源电路仿真技术02em

1、EM 仿真器 EM SightEMsightIntroduction to EMsightWhat is EMsightApplicationsIntegrationSignificant BenefitsBest ApplicationsBuilding a Hybrid Coupler (Hands on work)什么是EMsight2D Planar SimulatorCan Determine the electrical response of stacked two dimensional layers (2D) with interconnecting vias (+1/2D)

2、.Spectral Domain MoMUsing a numerical technique (Method of Moments), it solves low level physical rules (Maxwells Equations) for a general 2D Structure inside a metal box Linear SimulatorS parameters are output at the ports specified. No active devices are allowed. ME are solved for the currents on

3、the metal.Materials Allowed Conductors (Perfect and Real) Dielectrics (Plastics w/ and w/o Loss)Emsight元件的仿真Via Port This type of Port Allows an Electrical Port from the BottomElectrical PortThese are the electrical connections to the outside world. EMsight determines the signals received at all por

4、ts (S parameters) given excitation at one or multiple portsDe-Embedded PortEMsight will run a series of Calibration Standards to eliminate effects due to the metal wall using this portEach Layer has its own dielectric properties. These properties extend across the entire layer (Examples: Air, GaAs,

5、G10 etc)ConductorsPlanar Conductors, can be lossy real conductors such as Gold, Copper, Aluminum什么时候使用EMsightPerforming an EM simulation takes lots of time. Simulation time is not linearly related to structure size. (N cells N2 to N3)EM simulation is the most accurate simulation as it applies only l

6、ow level physical laws (Maxwells Equations)Reasons to UseWhen the existing model may not be accurate. No there is no existing model.When concerned if “uncoupled” parts of circuit are really coupled.得到什么类型的输出Port Electrical ParametersImage Currents and E-FieldsRadiation Patterns Many Formats Availabl

7、e S,Y,ZPage 6EM整合到MWO中Method 1: Layout is imported into EM SightWorks on general layout structures imported layoutsMethod 2: Extract to EM Sight From SchematicFaster for elements with schematic representationCan Control Multiple Extract BlocksMust Exhibit Caution “A little too easy”EM Sight Controll

8、ed in Project BrowserCan Look at Various EM SimulationsIntegrate results into graphs, and as subcircuitsCan Access External Simulators Through EM SocketSame “look and feel” as controlling EM SightEMSight应用Accurate S Parameter Models for Discontinuities This is How X Models Work.Create New Models (S

9、Parameters) for Unknown DiscontinuitiesPlanar FiltersCan Examine Coupling between ElementsPlanar Antennas天线What happen to the Metal BoxEMsight uses a trick to model antennas. It changes the top surface of the enclosure to be a very lossy metal. So lossy in fact that it looks like the antenna is radi

10、ating into freespace.The electric field is sampled at the top of the enclosure. Through a theorem derived from Maxwells Equation (Equivalence Theorem), equivalent currents can be derived which we place on an infinite ground plane. Radiation patterns can them be calculated from these currents. Types

11、of MeasurementsRadiation Patterns can be calculated for the following Polarizations (, , RHCP, LHCP, TPwr) and for the following swept parametersFrequency, and 平面仿真器(EM Sight)适用领域Typical Board, Package, IC Planar StructuresPlanar layers of metal and dielectric.Planar AntennasStructures with well def

12、ined ground planesMicrostripCoplanarTypical Structures of Interest to RF, Microwave DesignersMethods Use Greens FunctionsAssumes have parallel layers of materialssolve for currents on the metalNon Planar StructuresTrue “3D” Objects: Connectors, Bond Wires,.Discontinuities in the DielectricEdge of th

13、e PackageArbitrary BoxesEMSight is a rectangular box.Normally, you hope the box effect is negligible.Very thick linesBut.two lines on top of one another gets close.Greens Functions Necessitate:Planar Dielectric Layers to the Edge of the BoxHorizontal or Vertical Metal 平面仿真器(EM Sight) 不能用于例: 建立一个分支线定

14、向耦合器方法1 来自版图Build a 3 section 3dB branchline coupler using the schematic shownAim to build the “EMsight_p13.emp” projectImport the “duroid substrate.lpf”Simulate 1 to 20 GHzSet Frequency Sweep at Circuit Schematic LevelGraph S21 and S31Prepare EM Sight structureSimulate the coupler with EM SightComp

15、are modelled & EM Sight simulationsLook for resonances in the Structure3dB 耦合器原理图Use MTEE$建立一个3阶3dB分支线耦合器S21 和 S31MTEEX$ 模型The “X” means the model will run EM Sight in the background to get a good Tee ModelX Models are available for common discontinuitiesFreeze the GraphSelect the GraphGraph/Freeze

16、TracesChange the MTEE$ Models to MTEEX$ ModelsSelect all MTEE$ - use SHIFT for multiple selections.In Elements Right Click MTEEX$.Replace Schematic Selection Reserve ParametersResimulateX模式的影响Can See the effect of the X model建立一个3阶3dB分支线耦合器 方法1Create a New EM StructureRight click under the Project B

17、rowser EM StructuresFrequency Range Change to 10GHz to 20GHz Step 1GHzEnclosure Size: 495 mil by 400 milGrid: 99 by 80Dielectric Layers: Air and substrateBoundaries: Top & Bottom PerfectCopy and Paste the schematic layout into the enclosureAdd ports and de-embedCheck EM Structures, Information Simul

18、ate设置周界尺寸X-Dimension (mil) 500 X-Divisions 99Y-Dimension (mil) 400 Y-Divisions 80HINT: Check that the cell size is appropriate for the simulation.设置介质层Layer 1 Thickness (mil) 100 Er 1 Loss Tangent 0Layer 2 Thickness (mil) 20 Er 3.38 Loss Tangent 0.0027HINT: Highlight a row of data then edit values i

19、n the edit boxes.设置边界条件Enclosure Top & Bottom BoundariesPerfect conductor设置EM解算选项Select the appropriate EM solver optionsHINT: To access EM Options, right click on EM Structures in the Project Tree.检验解算选项View the EM Solver Information before starting simulation创建端口建立一个3阶3dB分支线耦合器Simulation time depe

20、nds upon:Number of frequency pointsEnclosure grid resolutionMinimum of 3 mesh cells across the narrowest structureMesh across the structureUnion shapes to avoid interface field calculationsReduce mesh on large shapesCurrent Animation optionsSwitch off if not requiredEM cache memory availableIncrease

21、 to the mended size to avoid hard disk delay检验3D图形EM结果Resonance?利用有理近似逼近迭代结果Create a Circuit Schematic EM_BranchlinePlace EM Structure 1 in as a subcircuitAttach PortsSet the Freqs to: 5-20 GHz .01 StepProject Options/IntepolationRational Functions/CartesianCurve is Well ApproximatedResonance!Build

22、a 3 Section 3dB Branchline Coupler Method 2Work in branchline schematicInsert Elements to Control EM Sight from SchematicElements/Simulation Control/EXTRACTElements/Substrates/NSUB设置NSUB修正基片值EM Sight Uses This for DielectricsWarning! EM Sight Doesnt Use This Line Info!建立抽取框架(Extract Block)EM_Doc = EM Structure Name in Project BrowserName = Name of Group of Elements to be ExtractedExtension sets