How to set the excitation of this antenna in HFSS 9.2 ?

[sanders]

How to set the excitation of this antenna in HFSS 9.2 ? Its radiating element are two triangular patches which is fed at the tips, a finite ground plane is under the substrate. Which kind of port is to use ? Wave port or lumped port ? and how to construct the structure of the feed, such as coax table or some other thing . Any help or advice will be appreciated!

Best regards!

 

[sanders]

please help me ,all friends! thank you !

 

[secondalinea]

Hi,
you have several possible choise.
1) you could reproduce the feed as it is in phisical reality
this means you need to draw the real feed
supposing it is a coaxial feed
you must draw the coax cable attach the internal pin to one of the triangle...and so on...
the port in this case it is a wave port and should be placed on the bottom surface of the coaxial cable.

2) you may want to neglect the real feed structure and use a gap source between the two triangles in this case you may draw a rectangle between the two triangles and assign a lumped gap sources to it

hope this helps

SL

 

[sanders]

hello secondalinea,
i got your main idea, but i have two questions:

1 when i draw a coax feed and use wave port, is it necessary to draw a real long coax table in order to let the wave port outside the radiating boundary?if not,what is the right method?

2 if i use a lumped port a rectangle will be drawn, in this case the rectangle touches the patch only at the tips, not a line as in many other cases,does this matter a lot?

thank you!

 

[secondalinea]

it is not necessary to make the coax cable so long to get
the border of the external box.
you can use a so called cap.
1)attach the port to the bottom surface of the coax
2) draw a thin cylinder made by perfect conductor exactly on the bottom surface of the coaxial with the same external radius of the coaxial

In this wayHFSS will not complain about the fact that the wave port is not at border of the external box.


For your second question I would cut a little piece of the vertex of the triangle
and use the resulting edge as the edge of the rectangle for the lumped port

SL

 

[sanders]

oh, i get your idea, just draw a pec cylinder to connect the real coax table having the same outer radious,then specify the interface wave port, right?

thank you for your indications! secondalinea!