I have a problem with the gain and efficiency of an antenna calculated by Momentum.

First, I simulate a microstrip dipole on a substrate fed by differential ports. The directivity is 2.65 dB, the gain is 1.42 dB and therefore the efficiency is 75% (some losses occur because of surface wave modes in the substrate).

Now, I simulate a similar dipole, but slightly assymetric. The impedance is almost identical since the dipoles are similar, but the efficiency is now exactly 100%, with the directivity and gain equal to 2.35 dB!

anybody can help?

thanks!

First, I simulate a microstrip dipole on a substrate fed by differential ports. The directivity is 2.65 dB, the gain is 1.42 dB and therefore the efficiency is 75% (some losses occur because of surface wave modes in the substrate).

Now, I simulate a similar dipole, but slightly assymetric. The impedance is almost identical since the dipoles are similar, but the efficiency is now exactly 100%, with the directivity and gain equal to 2.35 dB!

anybody can help?

thanks!

Thanks