I am looking to match an antenna design to an RFIC. I initially matched the antenna to the lumped port set to 50 ohms. I then changed the lumped port to the RFIC's impedance (63-j199), resimulated, and saw no difference.
Hi CDWest
Lumped port connecting only to one point but the input have width so it's not accurate. use face port or wave port it's better
look also at this examples. the ic is in the middle. look also at the concept of feeding.
Agreed. ... I usually need a huge inductor to match these chips. I see a very small difference in the input impedance (0.0001 delta), but nothing material (probably difference in the mesh).
The only thing I've changed is the Lumped Port defition. Images attached, if they're any help. Matching elements from left to right are: series-finite conductivity (copper), shunt-2.8pF, series-3nH, shunt-open. Port on left, antenna on right.
Thanks for the references. I'm working on a tag with a variety of other circuitry over a ground plane, so I'm trying to save space by matching with passives. I have been asked to provide simulation results with the chip impedance represented. The feed line is about lambda/50 in length, so I'm not too worried about its characteristic impedance... should I be at this size?