Lecture 2: Introduction

Transcription

1 Lecture 2: Introduction v Release ANSYS HFSS for Antenna Design ANSYS, Inc.

2 Multiple Advanced Techniques Allow HFSS to Excel at a Wide Variety of Applications Platform Integration and RCS Phased Array Antenna and Antenna Design Integrated Mobile Devices ANSYS, Inc. Biomedical Commercial Platform Integration

3 HFSS: Simulation Technologies Finite Element Method Enabled with HFSS Efficiently handles complex material and geometries Volume based mesh and field solutions Fields are explicitly solved throughout entire volume Frequency and Transient solutions Integral Equations Enabled with HFSS-IE Efficient solution technique for open radiation and scattering Currents solved only on surface mesh Efficiency is achieved when structure is primarily metal Hybrid Solutions Physical Optics Enabled with HFSS-IE High frequency approximation Ideal for electrically large, smooth objects 1 st order interactions FEM Transient Enabled with HFSS Ideal for fields that change versus space and time; scattering locations ANSYS, Inc.

4 ANSYS HFSS: Finite Element Method High Frequency Structure Simulator Full-wave 3D electromagnetic field solver Industry leading EM simulation tool Simulation driven product development Shorten design cycle First-pass design success Finite element method with adaptive mesh refinement Provides an Automatic, Accurate and Efficient solution Removes requirement for manual meshing expertise ANSYS, Inc.

5 Active Return Loss (db) HFSS and HFSS-IE: Offer Advanced Features for EM Design Advanced solver technology 3D Finite element Integral Equation Techniques Hybrid FEM-IE (FEBI) solver Physical Optics 2.5D MoM Solver Transient Analysis Advanced Features Frequency-dependent, anisotropic, non-linear, spatially dependent Curvilinear Mesh Elements in FEM and IE Screening and Layered impedance boundary conditions Output quantities Generalized / Active S-parameters Antenna trace characteristics (Beamwidth, SLLs) Near fields and far fields Design automation Parametric modeling Parametric sweeps Optimizations Sensitivity and statistical analysis Integration with ANSYS DesignXplorer High Performance Computing Scalable Multi-Threading Distributed Parametric and Frequency Sweeps Distributed memory solution for large scale simulations Domain Decomposition for Finite Arrays and Arbitrary Geometry Hierarchical distributed solutions Ansoft Corporation Active Return Loss Curve Info db(actives(p1:1)) Setup1 : Sweep1 db(actives(p2:1)) Setup1 : Sweep Frequency [GHz] array Ansoft Corporation -30 Name Theta Ang Mag m m m m Co-pol in E-plane (Trace Characteristic) m1 m m m array d( HFSS-IE Lossy Impedance Boundary Spatially Dependent Material Properties Curve Info lsidelobey lsidelobex xdb10beamwidth(3) db(dirtheta) Setup1 : LastAdaptive ANSYS, Inc.

6 HFSS Overview of Solution Process Initial Project Setup Design Solution Type Boundaries Model Setup Creating Geometry Geometry/Materials Excitations Automatic solution process generates accurate, efficient solution Solution Setup Analysis Solution Setup Frequency Sweep Analyze Viewing Results Results 2D / 3D Reports Fields Update Adaptive Mesh Generation ANSYS, Inc.

7 HFSS Automated solution process Initial Mesh Refine Mesh Geometry Initial Mesh Converged Mesh Initial Mesh Geometric Mesh Initial Mesh Electrical Mesh Seeding/Lambda Refinement Adaptive Port Refinement Convergence vs. Adaptive Pass Mesh Refinement Solve Adaptive Mesh Creation Quantify Mesh Accuracy No Max( DS )<goal? Yes Frequency Sweep Adaptive Mesh Refinement ANSYS, Inc.

8 Example: Adaptive Meshing Automatic Adaptive Meshing Provides an Automatic, Accurate and Efficient solution Removes requirement for manual meshing expertise Convergence vs. Adaptive Pass Meshing Algorithm Meshing algorithm adaptively refines mesh throughout geometry Iteratively adds mesh elements in areas where a finer mesh is needed to accurately represent field behavior Resulting in an accurate and efficient mesh Mesh at each adaptive pass ANSYS, Inc.

9 Half Wave Dipole Example Ideal Half Wave Dipole HFSS Model of Half Wave Dipole Antenna Resonant at 1 GHz λ/4 λ/4 Surrounding air box λ/2 Metal Wire 0 Current Excitation Voltage Finite element analysis of real half wave dipole antenna using HFSS Far Field Radiation Pattern Return Loss ANSYS, Inc.

10 HFSS: Getting Started Launching HFSS To access HFSS, click the Microsoft Start button, Select Programs > ANSYS Electromagnetics > ANSYS Electromagnetics Suite 15.0 > Windows 64-bit Select ANSYS HFSS. Setting Tool Options Note: In order to follow the steps outlined in this example, verify that the following tool options are set : Select the menu item Tools > Options > Modeler Options Click the Operation tab Use Wizards for data input when creating new boundaries: Checked Duplicate boundaries/mesh operations with geometry: Checked Click the OK button Select the menu item Tools > Options > Modeler Options. Click the Operation tab Select last command on object select: Checked Click the Display tab set default transparency to 0.7 Click the Drawing tab Edit properties of new primitives: Checked Click the OK button ANSYS, Inc.

11 HFSS Initial Project Setup Initial Project Setup Model Setup Design Solution Type Creating Geometry Geometry/Materials Opening a New Project If a new project and new design are not already opened, then: In HFSS Desktop, click the On the Standard toolbar, or select the menu item File > New. From the Project menu, select Insert HFSS Design. Set Solution Type Select the menu item HFSS > Solution Type Choose Driven Terminal Click the OK button Solution Setup Analysis Solution Setup Frequency Sweep Viewing Results Results 2D Reports Fields Extra: We could have selected Driven Modal for this problem to get the same results. If we were to use the Driven Modal solution type, it would require some additional port setup that can be avoided when using Driven Terminal ANSYS, Inc.

12 HFSS Model Setup Initial Project Setup Design Surrounding air box Solution Type Metal Wire Boundaries Model Setup Creating Geometry Geometry/Materials Excitations Excitation Solution Setup Viewing Results Analysis Solution Setup Frequency Sweep Results 2D Reports Fields Metal Wire 2 perfectly conducting cylinders with a length of approximately λ/2 Surrounding Air Box Air volume surrounding antenna element to allow radiation of fields, radiating boundary condition will be applied to outer surface to act as infinite free space Excitation Lumped port excitation applied to a rectangle drawn between each arm of dipole to provide an RF excitation to antenna element ANSYS, Inc.

13 Add Dipole Antenna Component Insert Dipole Antenna Geometry from 3D Library Components Select the menu item Draw > 3D Component Library > Antennas > Dipole Select Dipole_Antenna_1GHz_ADK Note: The antenna contains parameters for antenna dimensions, these could be changed before the 3D component is inserted or after to tune the antenna performance Click the OK button to insert component into Global Coordinate System Select the menu item View > Fit All > Active View. Or press the CTRL+D key ANSYS, Inc.

14 3D Component: Model Review Review of 3D Library Component: Dipole Antenna 3D components can be inserted into any design using any of the predefined components or can be created from any user defined geometry This Dipole antenna geometry created from the 3D component library contains geometry and excitation that defined a dipole antenna It does not include the geometry for an air volume surrounding the antenna The dipole antenna 3D component is fully parameterized and the geometry can be changed at any time by highlighting the component instance from the model tree 3D Component Instance Excitation Included in 3D Component Model 3D Component Geometry ANSYS, Inc.

15 Create Air Box Create Air box Select the menu item Draw > Region Padding Type: Absolute Offset Value: 75 mm Click the OK button Select the menu item View > Fit All > Active View. Or press the CTRL+D key Note: Air box sizing is chosen to approximately λ/4 away from radiating element. This is the suggested distance when using an Absorbing Boundary Condition (ABC). The finite element method only solves what is drawn in the model, if we want an air volume around the antenna element, we need to include this geometry in the simulation ANSYS, Inc.

16 Add Radiation Boundary Add a Radiation Boundary to Air box Select the menu item Edit > Select > By Name Select the object named: Region Click the OK button Select the menu item HFSS > Boundaries > Assign > Radiation Click the OK button Note: Radiation boundary assignment can be visualized by selecting the boundary condition in the Project Manager window. The radiation boundary acts as a way to extend and make the model look like it is surrounded by infinite free space ANSYS, Inc.

17 HFSS Solution Process Initial Project Setup Design Solution Type Model Setup Creating Geometry Geometry/Materials Solution Setup Analysis Solution Setup Frequency Sweep Analyze Viewing Results Results 2D Reports Fields ANSYS, Inc.

18 Analysis Setup Creating an Analysis Setup Select the menu item HFSS > Analysis Setup > Add Solution Setup Click the General tab: Solution Frequency: 1 GHz Maximum Number of Passes: 6 Maximum Delta S: 0.02 Click the Options tab: Select order of basis functions: First Order Click the OK button Add Solution Setup Note: The solution setup controls how the Adaptive Analysis is performed. The Solution Frequency indicates what frequency the solutions are evaluated and impacts the size of the initial mesh. Maximum Delta S controls accuracy of the process by indicating the allowable variation between consecutive meshes. It determines when the meshing process stops The Maximum Number of Passes indicates the maximum times through the adaptive meshing process before proceeding to the frequency sweep analysis. HFSS will proceed to the frequency sweep regardless of it meeting the Delta S convergence criteria ANSYS, Inc.

19 Analysis Setup Adding a Frequency Sweep Select the menu item HFSS > Analysis Setup > Add Frequency Sweep Select Solution Setup: Setup1 Click the OK button Edit Sweep Window: Sweep Type: Interpolating Frequency Setup Type: Linear Step Start: 0.8 GHz Stop: 1.2 GHz Step Size: 0.01 GHz Click the OK button Add Sweep ANSYS, Inc.

20 Analyze Save Project Select the menu item File > Save As Filename: dipole.hfss Click the Save button Validate Model Validation Select the menu item HFSS > Validation Check Click the Close button Note: To view any errors or warning messages, look at the Message Manager window. Analyze All Analyze Select the menu item HFSS > Analyze All After analysis is complete save the project Select the menu item File > Save Review solution Data Select the menu item HFSS > Results > Solution Data Select the Profile tab to view solution information Select the Convergence tab to show convergence, solved element count, and maximum Delta S Select Matrix Data tab to view S-parameters and Port impedance Click the Close button Solution Data ANSYS, Inc.

21 Solution Process: Review Initial Mesh Geometric Mesh Initial Mesh Electrical Mesh Seeding/Lambda Refinement Adaptive Port Refinement Mesh Refinement Solve Adaptive Mesh Creation Quantify Mesh Accuracy No Max( DS )<goal? Yes Frequency Sweep Adaptive Mesh Refinement ANSYS, Inc.

22 Plot Mesh Plotting the Mesh Select the menu item Edit > Select > By Name Select the object named: Region Click the OK button Select the menu item HFSS > Fields > Plot Mesh Create Clip Plane to View Mesh Throughout Region Right click on the Global:YZ plane in the design modeler tree Select Add Clip Plane from the context menu This will display a clip plane window with options A clip plane anchor will be displayed, moussing over this anchor in different area s will the clip plane view to be manipulated When the mouse is highlighted over the center of the clip plane anchor, the anchor will display a yellow arrow, with the yellow arrow displayed you can click and drag to offset the clip plane view Clip Plane Anchor Movements Offset within plane Rotate Offset normal to plane ANSYS, Inc.

23 HFSS Post Processing Initial Project Setup Design Solution Type Model Setup Creating Geometry Geometry/Materials Solution Setup Analysis Solution Setup Frequency Sweep Viewing Results Results 2D Reports Fields ANSYS, Inc.

24 Post Processing Create S-Parameter Report Create Reports Select the menu item HFSS > Results > Create Terminal Solution Data Report> Rectangular Plot Solution: Setup1: Sweep Domain: Sweep Category: Terminal S Parameter Quantity: St(Dipole_Antenna_1GHz_ADK_port1, Dipole_Antenna_1GHz_ADK_port1) Function: db Click New Report button Click Close button ANSYS, Inc.

25 Post Processing 2D Radiation Plot Create a Radiation Setup Select the menu item HFSS > Radiation > Insert Far Field Setup > Infinite Sphere Name: ff_2d Phi: Start: 0, Stop: 90, Step Size: 90 Theta: Start: -180, Stop: 180, Step Size: 2 Click the OK button Note: A radiation setup is required in order to create far-field reports, this can be done before or after the simulation has been run. The choice of Phi and Theta angles here will result in only cuts in the principal planes. Create 2D Radiation Plot Select the menu item HFSS > Results > Create Far Fields Report> Radiation Pattern New Report Window: Solution: Setup1: Last Adaptive Geometry: ff_2d Category: Gain Quantity: GainTotal Function: db Click New Report button Click Close button ANSYS, Inc.

26 Post Processing 2D Radiation Plot Create a Radiation Setup Select the menu item HFSS > Radiation > Insert Far Field Setup > Infinite Sphere Name: ff_3d Phi: (Start: 0, Stop: 360, Step Size: 5) Theta: (Start: 0, Stop: 180, Step Size: 5) Click the OK button Note: We didn t need to create 2 separate radiation setups, instead we could have used a single 3D pattern setup and create 2D and 3D plots from the same setup by selecting the correct phi and theta angles to be swept in the report creation window. Create 3D Polar Plot Select the menu item HFSS > Results > Create Far Fields Report> 3D Polar Plot New Report Window: Solution: Setup1: Last Adaptive Geometry: ff_3d Note: Make sure to select the correct radiation setup Category: Gain Quantity: GainTotal Function: db Click New Report button Click Close button ANSYS, Inc.

27 Post Processing Field Overlay Return to 3D modeler To return to the 3D modeler window, go to the menu HFSS > 3D Model Editor or double click on the design name Create Field Overlay From the 3D Model tree, expand the Planes From the tree, select the Global YZ Select the menu item HFSS > Fields > Plot Fields > E > Mag_E Solution: Setup1 : LastAdaptive Quantity: Mag_E Click the Done button Select the menu item HFSS > Fields > Modify Plot Attributes Select E Field in Plot Folder Window, Click the OK button E-Field Window: Click the Scale tab Scale: Log If real time mode is not checked, click the Apply button. Click the Close button To Animate the field plot: Select the menu item HFSS > Fields> Animate Click the OK button ANSYS, Inc.

28 Post Processing Radiation Pattern Overlay Turn off previous field overlay Select the menu item: View > Visibility > Active View Visibility Select tab: FieldsReporter uncheck visibility of all plots Create Radiation Pattern Overlay Right click on the 3D modeler window to display context menu From the context menu select: Plot Fields >Radiation Field Select Visible for the 3D Polar Plot that was created in a previous slide Set the Scale: 0.2 and select Apply Select: Close ANSYS, Inc.