TEM mode in microstrip line is even mode or odd mode?

[x529]

TE10 is even mode, TE20 mode is odd mode. I am confused that wheather TEM mode in microstrip line is even mode?
Thanks!

 

[biff44]

last time i looked, microstrip was Linear Space Electric mode, LSE.
is that not still the best way to look at it? that models to explain dispersion very well

 

[x529]

last time i looked, microstrip was Linear Space Electric mode, LSE.
is that not still the best way to look at it? that models to explain dispersion very well

Thanks for your answer. I'm sorry. I don't quite understand

 

[volker@muehlhaus]

To me, the question makes no sense.

We usually discuss even mode vs. odd mode for TWO parallel conductors over ground, i.e. a three conductor system.

 

[x529]

To me, the question makes no sense.

We usually discuss even mode vs. odd mode for TWO parallel conductors over ground, i.e. a three conductor system.

Oh, yes. This is because I want to know whether the TEM mode in microstrip line can excited odd mode or even mode. According the simulation, I find it may excited even odd, so I guess the TEM mode in microstrip line is even mode. I dont know whether it right? The TEM mode in microstrip line like the even mode in the picture, right?
Looking forward to your reply.

 

[volker@muehlhaus]

I don't understand your question. Do you understand the meaning of even and odd mode?

Fig. 6. Even-and odd-mode electric field lines.

Download scientific diagram | Even-and odd-mode electric field lines. from publication: Analytical Model for Optimum Signal Integrity in PCB Interconnects Using Ground Tracks | In this paper, we present analytical models for line impedance and the coupling coefficient in the presence of...

www.researchgate.net

Even mode and odd mode refers to two coupled microstrip lines, as shown in your screenshot. These can be excited even mode and odd mode, both is real and we need to consider both modes.

For simulation, we can represent the even and odd mode cases by a structure cut in half at the symmetry plane, with electric/magnetic wall to model (enforce) the symmetry.

In real life, we often want the coupled lines as a differential pair, so we have odd mode. But even mode can exist as a parasitic effect, so we usually consider both modes.

 

[PlanarMetamaterials]

I think a better way to phrase your question could be: does a microstrip mode exhibit physical symmetry about a vertical axis which bisects the shown transverse cross-sectional plane of the line?

To which the answer is: yes. The field profile is indeed similar to the "even" mode field profile shown in your figure.