RF one-shot circuit capable of producing 5-ns pulse
You could try delaying one input to a single-gate CMOS exclusive OR with an RC network such as 250 ohms/20pF. Drive the input &amp; R with a fast single gate buffer. 

You will get a pulse on each edge of the input waveform. 

Also, you might want to consider using about 1 meter of coaxial cable as a delay line.