  A novel time-reversal subwavelength transmission technique, based on pulse
shaping circuits (PSCs), is proposed. Compared to previously reported
approaches, this technique removes the need for complex or electrically large
electromagnetic structures by generating channel diversity via pulse shaping
instead of angular spectrum transformation. Moreover, the pulse shaping
circuits (PSCs) are based on Radio Analog Signal Processing (R-ASP), and
therefore do not suffer from the well-known issues of digital signal processing
in ultrafast regimes. The proposed PSC time-reversal systems is mathematically
shown to offer high channel discrimination under appropriate PSC design
conditions, and is experimentally demonstrated for the case of two receivers.
