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ADS Momentum finite ground plane?

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winglj

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ads momentum ground

Hi, everyone. I have a question about the ADS Momentum finite ground plane simulation.

I know that in order to get a good results for the software based on MOM, a infinite ground plane is needed. However, I also want to try the finite ground plane simulation in ADS Momentum.

However, it seems when I defined all the ports as internal ports, no matter whether the Ground reference port is added to a large size finite ground plane or not, the simulation results are abnormal.

I am wondering whether someone has some example for finite ground plane simulation of ADS Momentum or other EM software based on MOM. Thanks.
 

momentum ground port

Has any one got tutorials of ADS momentum with examples?
 

ads finite gnd layout

@winglj

to define finite ground plane you have two options,
draw finite ground plane on any layer and then insert air below this layer of large thickness then insert a via which connect your fininte ground layer to original infinte ground layer. (ok but not too efficient)

draw finite ground plane and insert ground refference port on it associate it to single port whom it would refference as a ground.

i hope it helped

Added after 1 minutes:

Abhishekabs said:
Has any one got tutorials of ADS momentum with examples?
Click to expand...

check ADS help it has good explanation of all issues regarding momentum
 

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    winglj

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momentum ground reference port

Don't forget to set the bottom of the workspace to be Open. By default, Momentum sets it to GND, which is basically a PEC boundary on the bottom of the (infinite) workspace. Since an infinite ground plane below your antenna will create undesirable effects on your radiation pattern (even if you put a large layer of air underneath the patch), you need to make sure that the substrate setup is set to use open lower boundary.

--Max
 

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    winglj

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ads ground plate

Hi, thanks for all your reply.

Actually right now I have figured out how to get the simulation right in Momentum. I need to assign the finite ground plane with a port as "GND reference port".

However, once I generate the "Layout Component" and do the "EM-circuit" co-simulation, the problems come up again. The "GND reference port" setting is auto-disabled. Moreover, even I connect the "GND reference port" manually to the schematic "GND" symbol together with other circuit element, the results still not be good.

For example, for the Wikison Power Divider, the infinite GND plane layout component together with the schematic resistor can generate a resonable results, but once I use the finite GND plane layout component in schematic and did the EM-circuit co-simulation, the results go bad again.

If someone meet this problem before, please let me know how to solve it. Thanks.
 

ports ads reference gnd single momentum

winglj said:
Hi, thanks for all your reply.

Actually right now I have figured out how to get the simulation right in Momentum. I need to assign the finite ground plane with a port as "GND reference port".

However, once I generate the "Layout Component" and do the "EM-circuit" co-simulation, the problems come up again. The "GND reference port" setting is auto-disabled. Moreover, even I connect the "GND reference port" manually to the schematic "GND" symbol together with other circuit element, the results still not be good.

For example, for the Wikison Power Divider, the infinite GND plane layout component together with the schematic resistor can generate a resonable results, but once I use the finite GND plane layout component in schematic and did the EM-circuit co-simulation, the results go bad again.

If someone meet this problem before, please let me know how to solve it. Thanks.
Click to expand...

That's a tricky one. Sounds like the EM analysis ground reference is not necessarily the same ground reference as the schematic ground. Some of the internal EM analysis ports are serial ports, so they are 1-ports with reference on whatever is considered the negative terminal for the port.

I guess it all hinges on how the ground is defined in the Momentum port. Either they have a bug in the port, or else they need to give you more information on why it is not the same as schematic ground.

Good luck with that one,

--Max
 

Does anyone have a tutorial on how to design CPWCGAP coplanar waveguide to match 50 ohms and also plot s-parameter results? I am new to this and have no idea as to how to setup the para metricized layout and layout look alike, optimize it. Is this the only methos to go about this?

Thanks a lot for your help!
 
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