hi jian plz help me with this file using ie3d

[ramani]

hi jian,

i have to simulate my stacked grounded coplanar waveguide structure using ie3d.
here with i have attached my structure plz help me to get the fields and scattering parametrs.

.

i am looking forward ur reply....

 

[jian]

Hi, Ramani: I don't see any attachment. Did I miss something? You can send me the file at: jian@zeland.com. I may try to help you tomorrow. It is late here now. Regards.

 

[ramani]

attachment is there in the link.

 

[jian]

HI, ramani: Here are some models (simple and complex) for you. Since I don't have all the dimenions, I just created the structure with some assumed values. Regards.

 

[ramani]

hi,jian,
thanks for your help. can u please tell me will the magnitude of electric field and magnetic field vary if simulate a structure in fdtd and mom.

and if so how far will be the variation.

 

[parris]

So pity that I can not open the file without the latest version.

 

[jian]

Hi, ramani:

Certainly, the metallic structure is changed. The field will change.

Hi, Parris:

Please send an e-mail to me and I can send you the files in earlier version. I do suggest you to upgrade to the latest version because it is much better. Regards.

 

[ramani]

hi jian,
in a grounded coplanar waveguide, i didnt find any ground plane that fully covers the bottom side.it covers only the signal conductor and upper left and right ground planes.
is it right? i saw the structure in 3d defined by u in ie3d like that.
how to define left and right beams in stacked grounded coplanar waveguide.
and also i need to compare the results by elevating the signal conductor line in stacked gcpw by various heighs. how to define elevated signal conductor line .
plz help me.........

 

[jian]

Hi, Ramani:

Do you mean that you do not see the via covering the full range of the cpw grounds on the sides? I purposely did it. You see I define the negative port on the side metals. Howevever, the port can not be defined on an edge with the side connected to the ground. I have to remove a small portion from it in order to define a negative port on it. This is a reliable way for a port like this. Regards.

 

[ramani]

thank you very much jian i undersood.
then how can i elevate the signal condutor hight by keeping the left and right ground planes in the same position.

will the performance of the waveguide improve if i do like that.

 

[jian]

Hi, Ramani:

I am not sure whether it will improve. Certainly, your substrate's sigma = 10 s/m and it is quite lossy. If your center conductor will not touch it (by inserting an isolation layer), it will reduce the loss significantly.

On IE3D, you can select all the vertices of the center conductor on all layers and change the z-coordinate of them.

Best regards,

 

[ramani]

hi jian,

how should be the value of s21 for better interconnect structure.
regards,
ramani

 

[jian]

Hi, Ramani:

For an interconnect (passive circuit), the best S21 is |S21| = 1 or 0 dB. However, you can not achieve it due to |S11| > 0 and there are other losses (metallic, dielectric, surface wave and radiation). For your semi-conductor substrate, it causes much dielectric loss. You do need some low loss isolation layer between the strip and the SI layer.

Best regards.

 

[ramani]

hi jian,
can u please give me the structure (sgcpw) by elevating the signal conductor height by some length.
looking forward your help.
with regards
ramani

 

[jian]

HI, Ramani:

I don' have all the dimensions and I am not sure how much I should elevate them. Elevating a layer is simple on IE3D. You select EDIT->LAYER->CHANGE LAYER Z-COORINDATE. Please remember to change the SUBSTRATES information if the substrates are changed simultanously. Regards.

 

[ramani]

hi jian,
when i did as u told , i dont find the central condutor height alone getting increased and left and right ground layers are in the same position.
i am also dont have particular height to elevate just i need to find the optimum height where i get low loss.
plz help me..
regards

 

[jian]

Hi, Ramani:

For your particular structure, the high loss should not be affected by the grounding metal much. Most of the loss is from your SI substrate with 10 ohms.cm. You need to put an isolation layer between this substrate and the center conductor. Regards.

 

[ramani]

Hi,Jian:
you have given me a structure called gcpwthick, thick in the sense do u mean the thickness of the substrate or thickness of the metal.
what material can be used for isolating the substrate and central conductor layer.
anticipating ur reply...
regards
ramani

 

[jian]

Hi, Ramani:

The "thick" model means that I created a thickness model for the metal. For the dielectrics, it is always simulated as it is. There is no option for it. Regards.

 

[ramani]

hi,jian,
what meterial i can use for isolating the central conductor and dielectric substrate. in multilayered architecture how it is possible.
is there anyother way available to modify the sgcpw structure to reduce loss and signal integrity effects ,like adding ring like metal to two upper gnd planes.
regards.