thanks for reply. Sure, I'm aware of the differences between Realized Gain and Gain and that's why I created this discussion, A Realized Gain higher than Gain is physically meaningless. So I was wondering why I got these results, if there is something wrong with my approach to simulation. Discussing the problem with other users, I realized that probably this strange behavior is due to the use of Lumped Port with complex impedance. Indeed, I'm simulating a printed meandered dipole working at ETSI UHF RFID band and I am using a Lumped Port with impedance 23.3+i*145, this to obtain a conjugate impedance matching (chip's impedance is 23.3-i*145). I see this approach is the most popular for simulating RFID antennas (at least, that's what I learned from documetations and scientific papers).nRegardsn