HFSS15: Incident Hertzian-Dipole Wave

An incident Hertzian-Dipole wave can be specified as either an Electric dipole or a Magnetic dipole. The Electric dipole simulates the field of an elementary short dipole antenna placed at the origin. The Magnetic dipole is useful for EMC/EMI applications.

1. Click HFSS>Excitations>Assign>Incident Wave>Hertzian-Dipole Wave.

2. Select the Vector Input Format as Cartesian or Spherical coordinates.

3. Enter the X-, Y-, and Z-coordinates of the Excitation Location and/or Zero Phase Position (the origin for the incident wave).

4. Click Next.

a. If you selected Cartesian, the Incident Wave Source: Cartesian Vector Setup page appears.

b. Enter the X-, Y-, and Z-components for the vector I*Dipole Length in the X, Y, and Z boxes. I is the current amplitude (peak value). Units are Amp-meters (A*m).

(For Magnetic Dipole, step 10 shows the vector definition.)

A single incident wave will be defined. Continue with Step 8 below.

5. If you selected Spherical, the Incident Wave Source: Spherical Vector Setup page appears.

a. Under IWavePhi, enter Start and Stop points and the number of sweep Points.:

Click View Point List to see the values of f.

b. Under IWaveTheta, enter values for Start, Stop, and Points.

Click View Point List to see the values of q.

c. Enter the f and q components of the vector I*Dipole Length in the Phi and Theta boxes. I is the current amplitude (peak value). Units are Amp-meters (A*m).

(For Magnetic Dipole, step 10 shows the vector definition.)

A spherical grid is created when q is swept through each f point. At each grid point, an incident wave is present traveling towards the origin of the coordinate system for the design. The number of incident waves and grid points can be calculated by multiplying the number of f points by the q points.

6. Click Next. the Incident Wave Source: Hertzian-Dipole Wave Options page appears.

7. Select the Radius of Surrounding Sphere. Inside this sphere, the field magnitude will be made equal to the field magnitude calculated on the surface of the sphere. To restore the default (10 mm), click the Use Defaults button.

8. Specify the type of Dipole as Electric Dipole [Magnetic current loop] or Magnetic Dipole [Electric current loop].

If you select Magnetic Dipole [Electric Current Loop], and click the back button to view the Vector Setup, notice that the text indicates that the vector is now defined as:

Im*dl*normal(LoopSurface)

9. Click Finish.The incident wave you defined is added to the Excitations list in the Project.