[SOLVED] HFSS simulation - RFID tag lumped port setup question

Hi all,

I just encounter a simple problem during my RF simulation.
Simulation antenna => A simple loop antenna with a internal transponder IC input (assume a NXP UCODE seriese)
And I am no sure how to setup the lumped port correctly, so I study from internet and come up with two possible answer. Please help to give a hint which one is correct, or either of them are wrong.

1. I saw someone mention that only one port is needed for loop antenna. Therefore I place one port, with connected GND aside, on the end of antenna, and open on another end. But it looks not like a real "loop circuit".



2. I place lumped port on each of antenna ends with same IC impedance (assume Z0=24-223j). So I set the impedance as 24-223j for port_1 and port_2. But I feel confuse that does this mean there is 2 times impedance for this setup?



I was use ADS to simulate the antenna with differential mode for two ports, so I can simulate the antenna easily. And I just learn HFSS recently, so there are some philosophy difference between these two software. Please help to give some instruction, thanks.

Kent

Welcome kent5566007,

Neither case appears to be correct. You do only need one port for a loop antenna, but the port needs to be in series with the loop. Just place the port inside of the gap in the loop.