Eigenmode solver is a hypothetical concept, and you can excite maximum 20 (or 25) modes simultaneously in HFSS.

Just increase the number of modes in the solution setup.

Hi Sudipta Maity I think your answer makes so HFSS solves for multiple eigenmodes, but I think Debapratim was asking about how to excite the modes simultaneously. Can you comment on this?

The query was related to 'Eigenmode Analysis' of the HFSS which is possible using eigenmode solver. No excitation is required in eigenmode solver. It is basically a source free analysis of an object.

If we want to excite two modes (not eigenmode in true sense), we have to observe the field patterns of those modes and we have to choose suitable feeding mechanism to excite those two modes simultaneously.

Mode is excited in the presence of external excitation. On the other hand, eigenmode is found without any excitation.

Green's function is related to mode, whereas eigenfunction is related to eigenmode. If eigenfunction is derived by considering the effect of excitation, we will get Green's function.

Hi all, I am sorry if my question was a little vague. I have simulated the SIW cavity and found out the eigenmodes. However, I wanted to see how the field distribution would look like, if I excite two degenerate eigenmodes simultaneously. I wanted to see the combined effect. But I think that is not possible using HFSS eigenmode solver.

Thanks for your valuable suggestions.

1. To obtain any results, I do use conventional solution procedure (HFSS v13 or less version).

2. As eigenmode solver does not need required any feeding mechanism to excite different modes, it is a hypothetical solution. In practice, we have to use some kind of excitation to give the RF signal input (and for out put also). Hence, I do not use eigenmode solve for application oriented work.

3. To identify different modes of an isolated resonator or waveguide, I do use eigenmode solver (without excitation)

4. Just to see field, you can use conventional solution procedure with excitation also. Select the object, right click, plot field patterns (E or H), then press enter (after selecting frequency). You will be able to see field patterns at that frequency.