I'm actually quite into amateur radio and you can have these things called 'beam waveforms' that concentrate electromagnetic radiation. This is the same principle as any "steerable radio antenna." HAARP and similar arrays for instance can be directed accurately to any location on Earth to pinpoint and direct the signal being broadcast. The U.S. Nexrad system is actually capable of creating beam waveforms too and are quite visible on unaltered graphical maps such that you can find online by the College of DuPage.