HFSS Guidance 2

Contents

1. How to observe multiple modes inside a waveguide? ......... 2 Assign excitation ....................................................................................................................................... 2

Change mode numbers for one of the two ports (use “4” if you want to check the first 4 modes) ........ 3

Simulate .................................................................................................................................................... 3

Check the fields of different modes .......................................................................................................... 4

Edit the source magnitude ........................................................................................................................ 4

2. How do I tell a mode is propagating or not? ....................... 6 Change the solution frequency to the frequency you’d like to observe .................................................. 6

Enlarge the length of the waveguide ........................................................................................................ 6

3. How to plot E&H field lines? ............................................... 8 Choose Vector_E ....................................................................................................................................... 8

Delete the mag_E pattern (to see more clear) ......................................................................................... 9

4. How to change the filling to lossy or magnetodielectric

materials? ............................................................................ 11 Lossy material ......................................................................................................................................... 11

Magnetodielectric material .................................................................................................................... 12

5. How to export HFSS data to MATLAB? .............................. 14 Export a rectangular plot data ................................................................................................................ 14

By TA: Sensong An

1. How to observe multiple modes inside a waveguide?

Assign excitation

Change mode numbers for one of the two ports (use “4” if you want to check the

first 4 modes)

Simulate

Check the fields of different modes

Edit the source magnitude

Change the value of each magnitude so we can see the corresponding modes E-

field distribution (for example, TE10 & TE20 modes)

2. How do I tell a mode is propagating or not?

Change the solution frequency to the frequency you’d like to observe

By running frequency sweep doesn’t mean that HFSS is saving E-field pattern for

each single frequency inside this frequency range, it only saves the pattern of the

solution frequency; change the frequency to the value that you are interested in:

Enlarge the length of the waveguide

By enlarging the length of the waveguide, it’s obvious that whether a mode is

propagating or not, like for this mode,30 GHz is below the cutoff frequency, so it’s

not propagating:

3. How to plot E&H field lines?

Choose Vector_E

Delete the mag_E pattern (to see more clear)

(Same procedure for the H lines)

4. How to change the filling to lossy or magnetodielectric materials?

Lossy material

Any materials with relative dielectric loss tangent larger than 0 can be considered as lossy

material

To make sharp contrast, you can set the value to be relatively large

Magnetodielectric material

Any materials with relative permeability larger than 1 can be considered as

magnetodielectric material.

But pay attention, for dielectric material, it’s conductivity cannot be too large, or it will be

considered as medal.

Ferrite is widely used as magnetodielectric to change the propagation constant of a

waveguide.

Or you can build your own magnetodielectric material, as long as it’s permittivity &

permeability & conductivity value make sense.

5. How to export HFSS data to MATLAB?

Export a rectangular plot data

Then you can copy&paste the EXCEL data to a MATLAB array.