| Author |
Message |
Asim Ali Khan
Joined: 12 Dec 2005
Posts: 25
|
 29 Jun 2007 15:18 Transition Microstrip to Rec waveguide using HFSS |
|
|
|
|
Dear All
I am dealing with the transition from microstrip line to waveguide both are on substrate (PCB). I hv poblem assigning the excitation for my design. Actually I have three layers in my design one is the PCB substrate and the other two are copper layers sandwitching the substrate. How should I assign the excitaion should I select all three faces or just the substrate.
Thx in advance
Bye
|
|
| Back to top |
|
 |
burton
Joined: 12 Dec 2003
Posts: 198
Helped: 9
|
29 Jun 2007 21:21 Re: Transition Microstrip to Rec waveguide using HFSS |
|
|
|
|
First, you should build the electromagneticl model with back-to-back transition (that is, microstrip-transition-waveguide-transition-microstrip). In addtion, air box should be used for the open structure.
Secondly, you use the waveport for the excitation of microstrip.
I hope this can help you.
|
|
| Back to top |
|
|
Azulykit
Joined: 18 Feb 2007
Posts: 851
Helped: 103
Location: All over the Map.
|
30 Jun 2007 6:58 Re: Transition Microstrip to Rec waveguide using HFSS |
|
|
|
|
I concur with Burtons comments. You would also be well served if you read the section in HFSS where they discuss impedance calculation.
There are several twists with waveports that can easily be avoided.
|
|
| Back to top |
|
|
xibillian
Joined: 02 Nov 2006
Posts: 14
Helped: 1
|
30 Jun 2007 22:23 Transition Microstrip to Rec waveguide using HFSS |
|
|
|
|
i think you should search and get some info about SIC concept.
its pretty bulky,transition to microstrip from waveguide...
|
|
| Back to top |
|
|
Asim Ali Khan
Joined: 12 Dec 2005
Posts: 25
|
01 Jul 2007 22:43 Re: Transition Microstrip to Rec waveguide using HFSS |
|
|
|
|
Thx for ur suggestions guys. Let me clear one thing in my case both the waveguid and microstrip line are on the same PCB i.e. integrated on PCB.
But I do not understand "SIC" wht is this?
Added after 10 minutes:
Thx for ur suggestions guys. Let me clear one thing in my case both the waveguid and microstrip line are on the same PCB i.e. integrated on PCB.
But I do not understand "SIC" wht is this?
|
|
| Back to top |
|
|
maxwellian
Joined: 22 Feb 2005
Posts: 129
Helped: 18
|
03 Jul 2007 0:32 Re: Transition Microstrip to Rec waveguide using HFSS |
|
|
|
|
| Asim Ali Khan wrote: |
Dear All
I am dealing with the transition from microstrip line to waveguide both are on substrate (PCB). I hv poblem assigning the excitation for my design. Actually I have three layers in my design one is the PCB substrate and the other two are copper layers sandwitching the substrate. How should I assign the excitaion should I select all three faces or just the substrate.
Thx in advance
Bye |
Microstrip port:
Can't you just put a layer of air above the PCB and set a waveport over the entire end of problem, which includes the air, PCB and the microstrip line? Then set your impedance line between microstrip and lower ground plane. Remember to set the waveport to include the face of PCB and air.
Waveguide port:
I would just set the waveport to cover the area of PCBs, from lower ground to upper ground. You might need to put small metal bodies on each end of your waveguide at the port face to connect the top and bottom ground planes. I think you could just put your impedance line to stretch from top to bottom ground plane near the middle of the waveguide.
Hope this helps...
--Max
|
|
| Back to top |
|
|
Azulykit
Joined: 18 Feb 2007
Posts: 851
Helped: 103
Location: All over the Map.
|
05 Jul 2007 17:00 Re: Transition Microstrip to Rec waveguide using HFSS |
|
|
|
|
I keep re-reading your question and your objective is not clear to me. Are you trying to transition from microstrip to rectangular waveguide? That is often done.
Or are you trying to transition from microstrip to strip line? This is also possible.
Part of my quandry is that when someone says waveguide they usually (but not always) are referring to rectangular waveguide. I am trying to understand how that fits with your comment about three conductors (usually the situation with stripline).
Or do you have something else in mind? Maybe microstrip to some kind of dielectric filled waveguide in the PCB? If that is the case you open the door to a discussion of via's (blind, buried, and through).
Your intent is not clear to me.
|
|
| Back to top |
|
|
Google
AdSense
|
05 Jul 2007 17:00 Ads |
|
|
|
|
|
|
| Back to top |
|
|
Asim Ali Khan
Joined: 12 Dec 2005
Posts: 25
|
06 Jul 2007 13:09 Re: Transition Microstrip to Rec waveguide using HFSS |
|
|
|
|
Dear Azulykit
I am talking about microstrip to SIRW structure. Now I have a problem with HFSS simulation. When I run the validity check it gives me all ticks but when I start simulation it gives me error saying "Not enough triangular structers to model blah blah ...."
Secondly, I have designed the structure such as substrate (a box) is sandwitched b/w to conducs (rectangles) for micro strip operation I have to make the base conductor ground. Should I separate the microstrip base(ground) to the SIRW base?
Asim
|
|
| Back to top |
|
|
xibillian
Joined: 02 Nov 2006
Posts: 14
Helped: 1
|
08 Jul 2007 20:58 Transition Microstrip to Rec waveguide using HFSS |
|
|
|
|
Mr. Khan,
there is another way of reconstructing a waveguide on a pcb. they called it substrate integrated circuits (SIC). im actually working on that.
you may contact me personaly.
bkadi(AT)gyte.edu.tr
|
|
| Back to top |
|
|
