Unbalaced current in Antenna

What does it mean by unbalanced current in an antenna.
Is it due to the unequal current when gourd size is different in different direction

Sometimes it means that some of the current flows common mode on the transmission line and the current in the two halves of the dipole have unequal current. The sum of the three currents is equal to the differential mode current on the transmission line.

Can u please refer any book or some paper.I failed to find an article on the subject.

Thanks

Search on "Balun" here and on the web. There are numerous references. Balun is a contraction for balanced to unbalanced transformer. "Antenna Engineering Handbook" John Volakis and the earlier editions by Jasik and Johnson (there are three) will have examples and references cited.

unbalanced means the current will flow in both the antenna itself and in the ground plane so it will be unbalanced, this is just brief answer, because it is a big subject, i have my paper i can send it to you, it will give you good understanding in that.

Dear adolrauf, Please upload the paper as it will help everybody.