problem with simulation in HFSS

[Bou]

gd morning


please , I need someone to explain to me how we define the port in hfss and the boundary and what are the rule of
" asign perfect E ..."

Many thanks

 

[eraste]

There are differents ports in HFSS wave port , lumped ports. See the Help for more explanation. Wave port are used for wave guide structure (coax, hollow wave guide), when the transverse geometry is constant along one axis. Lumped port are used to feed antenna or other microwave system like coupler, filter ...
Bondaries conditions depend on your structure.If the system is closed bondaries depend : it must be a perfect E conductor if there are no loss, perfect H , it must be lossy (complex permittivity , complex permeability, finished conductivity).
For HFSS to defined a problem you have to construct the geometry of your system, define the bondaries (the material and the excitations). In fact it is just the parameters of the Maxwell equations solved with the finite elements method.

Bye for now.

 

[Bou]

10 x for ur answer

my prb is that I simulated an antenna in ads momentum I've got minimum of S11=-30 db at 869 mhz and I want to do the same thing whith hfss
but I've got only a minimum of -0.25 db at 800 mhz I don't know the cause of this, port ( lumped port) or boundary definition

 

[eraste]

Well,
could you give the schematic of your antenna ? If your S11 is too high perhaps you have wrongly design your lumped port ? Show the convergence of HFSS, if the process hasn't converged the post data are wrong. Have you got warning after checking your entire design (see the validate icon of HFSS) ?

 

[Bou]

do you know the printed inverted F antenna?

please can u send me a simple example how we can defin the port and the boundary for this antenna?

waiting for ur help
an example with conductor via plsssssss

 

[eraste]

Hi,

Have a look at this website : https://www.antenna-theory.com/antennas/patches/pifa.php
In HFSS, you can draw a 50 ohms coaxial line to feed this antenna. Look at the HFSS tutorial : there is one example that deal with a rectangular patch antenna feed by a coaxial line. A PIFA antenna will not be difficult to draw on HFSS.

 

[Bou]

10x eraste for ur help,

I m looking now for how I can defin a via conductor in HFSS.

any ideas??