Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

Grounded coplanar waveguide

Status
Not open for further replies.

jmb22

Newbie level 2
Joined
Nov 12, 2004
Messages
2
Helped
0
Reputation
0
Reaction score
0
Trophy points
1,281
Activity points
30
Hi,

I am trying to get simulation of the magnetic field behaviour for a grounded coplanar waveguide. I am using HFSS for 3 days now. And my only success has been to install the software.
Basically, I designed the GCPW using 2 wave ports. However, I can't get an output that makes sense. I calculated the width and gap to get impedance match to 50Ohms using TXLine.
First, how do you define the 3 ground planes as "ground plane". Basically, they are not really plane but rather box so I can't use the option of HFSS.

I am not interested to generate specific mode in GCPW except a quasi TEM mode. I am planning to use the GCPW as a broadband transmission line (5GHz to 40GHz)

Second: should I define any mesh operations?

Also, if the rectangle that defines the Wave ports are such that they are connecting the central line, the 2 ground planes on top of the substrate and the ground plane on the bottom, then I obtained the follwoing:

[error] Port refinement, process abc3d died unexpectedly.

My question: WHY?

If I adjust the ports so they are only connected to the top metallic layers, then it "works": no error message.
However, the direction of H field lines and the amplitude do not make sense?

Thanx for your help.
 

harmony

Member level 2
Joined
Oct 31, 2004
Messages
42
Helped
1
Reputation
2
Reaction score
0
Trophy points
1,286
Activity points
373
look man,
ur case is some how complicated, as u cant define ur wave guide as a (grounded ) CPW, but rather a (Microstrip) !
I've done some similar work in my master b4 like urs, and the best to simulate such structure is to consider it a microstrip or a sort of mixed tx-lines.
have u ever used SONNET ?
try it, it might b helpful 4 ur case
Goodluck !
 

rugbyfun

Junior Member level 2
Joined
Oct 21, 2004
Messages
22
Helped
1
Reputation
2
Reaction score
0
Trophy points
1,281
Activity points
238
Hi,
when you draw an object you can assign
Perfect conductor to it.

HFSS will consider it a s perfect conductor not as a ground since perfect ground does'not exisit in reality....
and in any case you do not need a perfect ground to create a CPW
exitation.

If you have a legal copy of HFSS and you cannot obtain
a results in 4 day I would strongly suggest
to contact the customer service of Ansoft in your area
you certenely wil get an answer and all the training material for
your application

Rugbyfun
 

Status
Not open for further replies.

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Top