Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronic 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.

Register Log in

wavegiude analysis that is more than 10 wavelengths long

Status
Not open for further replies.

sviodo

Member level 4
Joined
Jan 2, 2002
Messages
68
Helped
1
Reputation
2
Reaction score
1
Trophy points
1,288
Activity points
533
combining modes 1 and 2

i need to analyse waveguide that is that is more than 10 wavelengths long
i couldn't cope with the problem in hfss (problem was too big), maybe you could recommend me appropriate tool?

With regards,
 

yuyu

Advanced Member level 4
Joined
Mar 27, 2002
Messages
108
Helped
13
Reputation
26
Reaction score
12
Trophy points
1,298
Activity points
1,018
Dear Sviodo,
I think that you can try to use CST Microwave Studio.
This SW is a 3D e.m. simulator, FDTD method based.
If the problem is too big, it is possible to slice the model in several blocks each e.m. analyzed and described by its own generalized S matrix.
Then it is possible to combine the S paramiters by a circuital simulator taking in account higher order modes also if they are evanescent modes at the interfaces between two blocks.
For this purpose I suggest the software CST Design Studio.
 

eirp

Advanced Member level 1
Joined
Dec 11, 2001
Messages
466
Helped
29
Reputation
56
Reaction score
19
Trophy points
1,298
Location
Phase center
Activity points
5,142
Hi, sviodo!

Please describe more the problem if possible. If you have straight waveguide with arbitrary cross section, it can be made by your own..
If you're familiar with with Matlab programing and solving PDE's, you can solve Helmholz the equation for transverse eigenvalues and eigenfunctions. If you compute enough number of modes (very fast), it's possible to build S matrix.
Similar method is used in MWS (eigenmode solver). Look into manual how it works. This solver is appropriate and efficient for this task.
Regards,
Eirp
 

sviodo

Member level 4
Joined
Jan 2, 2002
Messages
68
Helped
1
Reputation
2
Reaction score
1
Trophy points
1,288
Activity points
533
thx for your advice, i develope the program in matlab but i need to check design before it'll be produced, seems that i can use mws :)

Regards,
 

loucy

Advanced Member level 1
Joined
Aug 26, 2001
Messages
414
Helped
24
Reputation
48
Reaction score
11
Trophy points
1,298
Activity points
4,657
You have discontinuities all over these 10 wavelength? Why can't you use divide and conquer.
 

sviodo

Member level 4
Joined
Jan 2, 2002
Messages
68
Helped
1
Reputation
2
Reaction score
1
Trophy points
1,288
Activity points
533
you suggest to analyse sth like 20 divided parts and combine results?
i do belive that this could be solution in case of 2-3 divided parts but does not apply to my case...

plz correct if i misundersood you
 

filterman

Member level 2
Joined
Jan 18, 2002
Messages
52
Helped
1
Reputation
2
Reaction score
1
Trophy points
1,288
Activity points
512
Using FTDT (CST,QW3D,Fidelity,etc) is O.K. , but if problem can be analized in mode-matching software(mician's wizard or Wasp-net) then your results will be faster and more accurate-you might end up with a producable non tunned device.
 

eirp

Advanced Member level 1
Joined
Dec 11, 2001
Messages
466
Helped
29
Reputation
56
Reaction score
19
Trophy points
1,298
Location
Phase center
Activity points
5,142
Dear Sviodo,

please can you post a simple sketch of your problem?
Maybe we can learn something new and interesting!
Eirp
 

loucy

Advanced Member level 1
Joined
Aug 26, 2001
Messages
414
Helped
24
Reputation
48
Reaction score
11
Trophy points
1,298
Activity points
4,657
Why you can do 2 to 3 divided parts, but not 20 divided parts?

I think "divide and conquer" is a simplified case of mode matching. Suppose one can ignore the higher order mode coupling between these parts, then each part is a simple two port. Higher order modes should be included only when the discontinuities is close (1 lamda_g or 1/2 lamda_g ? there is no rule) to the dividing plane.
 

mike_bihan

Full Member level 3
Joined
Mar 21, 2002
Messages
185
Helped
0
Reputation
0
Reaction score
0
Trophy points
1,296
Activity points
1,544
why not use 2-D simulator

why not use 2-D simulator?
 

sviodo

Member level 4
Joined
Jan 2, 2002
Messages
68
Helped
1
Reputation
2
Reaction score
1
Trophy points
1,288
Activity points
533
you sure that you can use 2d simulator to analyse for example magic T
or E junction ?
 

Kit-the-great

Full Member level 3
Joined
Mar 30, 2002
Messages
151
Helped
5
Reputation
10
Reaction score
3
Trophy points
1,298
Location
Russia
Activity points
1,317
You may try to use MuWave Wizard for fast calculation, or divide the structure to simple parts and analyze each by Markuvitz's Waveguide handbook formulas. In any cases, please, try to post the some skethes of Your problem for our better understanding of it.

With responce,
kit-the-great
 

lindaknoll2002

Member level 2
Joined
Jul 12, 2002
Messages
45
Helped
2
Reputation
4
Reaction score
2
Trophy points
1,288
Activity points
277
I have used hfss to simulate waveguide structutres with more than 20 wavelength long and did not have any problem. The only thing i remembered is that in the old version of HFSS it does not allow the ratio between longest and shorted objects be more than 4000. So make sure no object is too small.

Linda.
 

Status
Not open for further replies.
Toggle Sidebar

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Top