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2D coplanar waveguide Port Modeling

Posted 4 apr 2013, 05:53 GMT-4 RF & Microwave Engineering, Geometry Version 4.2a 4 Replies

Diana Geiger
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Hello everyone,

I have a very simple 2 D model of the crossection of a coplanar waveguide (substrate in an air box, at the boundary between substrate and air I have lines for the metallization). I want to set the center conductor line as active port. However, I cannot select any of the metallization lines for the port. Can anyone advise me how to deal with the port issue?
4 Replies Last Post 22 apr 2013, 06:46 GMT-4
Edgar J. Kaiser Certified Consultant
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Posted: 1 decade ago 4 apr 2013, 06:05 GMT-4

Diana,

port boundaries must bei PEC or impedance boundary conditions. That is what I stumbled across when I tried it the first time.

Cheers
Edgar

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Edgar J. Kaiser
www.emphys.com
Diana, port boundaries must bei PEC or impedance boundary conditions. That is what I stumbled across when I tried it the first time. Cheers Edgar -- Edgar J. Kaiser http://www.emphys.com
Diana Geiger
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Posted: 1 decade ago 16 apr 2013, 12:20 GMT-4
Hello,

thank you for your reply. However, I am still confused since also the impedance boundary condition does not take my boundary choice. Maybe there is something altogether wrong with my model of the cross section, could someone take a look? I simply want to include a RF excitation (travelling into the plane of my model) to the center conductor and see the field distribution.
Hello, thank you for your reply. However, I am still confused since also the impedance boundary condition does not take my boundary choice. Maybe there is something altogether wrong with my model of the cross section, could someone take a look? I simply want to include a RF excitation (travelling into the plane of my model) to the center conductor and see the field distribution.

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Edgar J. Kaiser Certified Consultant
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Posted: 1 decade ago 16 apr 2013, 12:56 GMT-4
Diana,

I indeed think that the model is not appropriate. My comments:

1. The metallization is modelled infinitely thin. This results in singularities

2. In planar symmetry you can't send a wave into the plane. If you connect a lumped port it would be connected all along the plane's normal direction. This is probably not what you want.

I put a lumped port into your model to show in principle how a lumped port is to be defined. The lumped port always connects two PEC or impedance boundaries. However for the above mentioned reasons this will still not do what you want.
I think you must go to 3D and model the conductor with finite dimensions, not just as boundaries.

Cheers
Edgar

--
Edgar J. Kaiser
www.emphys.com
Diana, I indeed think that the model is not appropriate. My comments: 1. The metallization is modelled infinitely thin. This results in singularities 2. In planar symmetry you can't send a wave into the plane. If you connect a lumped port it would be connected all along the plane's normal direction. This is probably not what you want. I put a lumped port into your model to show in principle how a lumped port is to be defined. The lumped port always connects two PEC or impedance boundaries. However for the above mentioned reasons this will still not do what you want. I think you must go to 3D and model the conductor with finite dimensions, not just as boundaries. Cheers Edgar -- Edgar J. Kaiser http://www.emphys.com

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Purushottam Garg
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Posted: 1 decade ago 22 apr 2013, 06:46 GMT-4
how to design input and output coplanar waveguide so they can be coupled .
how to design input and output coplanar waveguide so they can be coupled .

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