New Theory Leads to Gigahertz Antenna on a Chip

You can see such symmetry breaking in a once-common 20th century technology: the two-wire ribbons used during television’s first few decades to send RF signals from rooftop VHF antennas to television sets without any loss. The electric RF current in the two conductors flow in opposite directions and have opposite phase. Because of the translational symmetry (the two conductors are parallel) the radiation fields cancel each other out, so there is no net radiation into space. But if you would flare the ends of the two conductors at one end of the ribbon, they aren’t parallel anymore and you break the translational symmetry. The two electric fields are no longer aligned and don’t cancel each other out, causing the RF signal to be converted into electromagnetic radiation.

via New Theory Leads to Gigahertz Antenna on a Chip – IEEE Spectrum.