cst discrete port

HI,all.
when I use the MWS to simulate a simple example that two differential microstrip are on the plane, I define fore discreate port between the end of the strips and the plane. But when I simulate the model .it tell me that the port are not on the perfect conductor.
another question about the wave port. When I defined wave port and simulated the model. it tell me the number of note on the port is too small.
So how to solve these problem?
by the way, can somebody tell me how to define the wave port and descrete port,such the aspect radio of the port.
Thank you.

Hi,

1) Discrete port

- use picks to locate conductors. Select 2 points (strip and ground plane). Discrete port then use picked points locations.
Discrete port (at other words scalar one) insn't well suitable for microstrip because this kind of port doesn't create wave and thus doesn't respect Q-TEM nature of microstrip line. Results will be very poor.

2) Wave port

Wave port must have at least 3 meshcells at direction of travelling. For example if you have coax at XY plane (transverse), Z direction must be homogenous at min 3 meshcells - coax's length must be enough to satisfy this (depends also at frequency and meshing params).

? What do you mean by "aspect ratio"?

BTW can you post your projects here (without results and packed) ?

Then we can help you better 8)

Rgz,
Eirp

hi yuanzy97


first you have to get ver 4.2 or more
than pick 4 points rectangulr around the microstrip port
define wave port and then mark the littel box "Free"
then in the bounding box choose in the diraction of the
microstrip port "Open add space" that's what new in
ver4.2 it let you to define port into metal or to define
bounding box away from the port not like the previous version

RGZ

plasma

Hi, Rgz, thank you to reply my question. you are so kind to me.
The aspect ratio of means the ratio of the width to length of rectangle of wave port .suppose I define the 4(width)×6(length) wave port, if will notify me that the note is not enough. but if I define the 3×6 or 2×6 wave port, it will run. I don't understand this problem.
I attach my model on the web.Please check my model.
:)

thank you and all.

For what do you use that function?
I don't think you need to upgrade to ver 4.2 because of that.

What you described is moving the reference plane, thus just offsetting the phase and loss with the port mode parameters.
And regarding lossy port in older CST versions: you just add PEC for three mesh cells in front of the port. I can't think that three mesh cells will throw you phase off.

i'm doing patch antenna to get multiband frequency.....
after i"ve done the analysis the result have symbol warning say :
maximum number of pulse width simulated, solver stopped. please note that the steady state energy criterion has not been satisfied..... what is that mean?
what should i do to fix it?

@paefaezah

to resolve this problem u can increase the number of frequency samples and maximum number of pulse witdh which is under the special tab in transient solver

Hello,

can anyone suggest how to declare a discrete port for a co-planar waveguide antenna design?

Initially I used waveguide port, and it works perfectly. However, how can we declare a discrete port to a co-planer designs?

thanks in advance for the help/info.
Nurul

I would suggest that use adaptive meshing option. In transient solver option tick the adaptive meshing. As a default it will do the 6 passes. For antenna applications keep accuracy level below -40 dB. I keep it at -60 dB.

In case all the 6 passes are over and you still not getting the steady state then redo the adaptive meshing and choose option of continue the present settings.

Choosing lossy materials and conductors in place of lossless dielectrics and PEC is recommended.

Regards