Tell us about yourself!
With great difficulty!. You could try a parabolic metal mirror.
Wrong! An electromagnetic pulse is made of multiple frequencies (harmonics) though they tail off in amplitude the further you get away from the base frequency. If the Pulse duration is, say, 1ms that's a base frequency of 2khz, you then get odd harmonics at 3x,5x,7x etc. Just Google for square wave harmonics.