Lesson 20 – 2D TF/SF Simulation and RCS Detection

2D TF/SF Simulation and RCS Detection Introduction

2D Total Field/Scattering Field (TF/SF) is a special excitation type that excites arbitrary tilting plane wave in the enclosed rectangular surface. Inside the rectangular region, it generates the total field. Outside of this rectangular region, it is the pure scattering field. TF/SF  simulation enable RADAR cross Section analysis. Complex grating layout analysis and other plane wave…

New Layout

Step Action 1 Open OptiFDTD Waveguide layout Designer From the Start menu, select Programs ->Optiwave Software -> OptiFDTD-> Waveguide Layout Designer. OptiFDTD_Designer window opens. 2 Create a new project. From the OptiFDTD_Designer File menu, select New. The Initial Properties dialog box appears. 3 Define the material(s) and waveguide profile(s) that will be used in the project.…

Input Wave

To insert the TF/SF plane wave excitation follow the steps below: Step Action 1 From the Draw menu, select TFSF region. 2  Click in the layout window at the position where you want to insert the TFSF region. A Green/red rectangular region that represents the TFSF appears in the layout window. (Figure 9) Figure 9: Initial…

Simulation Parameters

Step Action 1 From the Simulation menu, select 2D 32bit Simulation Parameters. Simulation parameters dialog box appears 2 Select TE as the 2D simulation type 3 Turn off the auto check for Mesh Delta. Type the following values for the mesh size: Mesh Delta X (um): 0.01 Mesh Delta Z (um): 0.01 4 To set…

32-bit FDTD Simulation

Step Action 1 From the Simulation menu, select the “2D 32bit simulation parameters“ 2 Click Run to start the simulation. The Simulator window appears (Figure 14). It displays the time domain response for TFSF excitation. Figure 14: 2D Simulator window When Simulation is finished, you will be asked if you want to open the analyzer…

Steady State Response

Step Action 1 In the analyzer window, Click Ey(DFT) AMP button under the graph window to observe the steady state response for this TFSF excitation in free space (Figure 15). 2 Click Hx(DFT) AMP button or Hz(DFT) AMP button to Observe other field components. 3 In the Components menu, click field components and select phase…

RCS Calculation for an Infinity Cylinder

Step Action 1 Re-open this layout in the OptiFDTD Designer. 2 Select “Elliptic Waveguide” under the Draw menu, or select the Elliptic Waveguide in the shortcut toolbar. 3 Left-click and do not release the mouse to draw an elliptic waveguide in the layout. release the mouse by clicking the arrow toolbar. 4 To adjust the position…

References

[1] Umashhankar K. R, Taflove A.A “Novel method to analyze electromagnetic scattering of complex objects”, IEEE Trans. On EMC, 1982, 24(4), pp. 397-450