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2D coplanar waveguide Port Modeling

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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 2013年4月22日 GMT-4 06:46
Edgar J. Kaiser Certified Consultant

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Posted: 1 decade ago 2013年4月4日 GMT-4 06:05

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
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

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Posted: 1 decade ago 2013年4月16日 GMT-4 12:20
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.


Edgar J. Kaiser Certified Consultant

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Posted: 1 decade ago 2013年4月16日 GMT-4 12:56
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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Posted: 1 decade ago 2013年4月22日 GMT-4 06:46
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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