  Motivated by the challenges of future 6G communications where terahertz (THz)
frequencies, intelligent reflective surfaces (IRSs) and ultra-wideband (UWB)
signals coexist, we analyse and propose a set of efficient techniques for
configuring the IRS when the signal bandwidth is a significant fraction of the
central frequency (up to 50%). To the best of our knowledge this is the first
time that IRS configuration techniques are analyzed for such huge bandwidths.
In our work we take into account for the channel model, the power spectral
density of the signal reflected by the IRS and the network geometry. We
evaluate the proposed solutions in terms of achievable rate and compare it
against an upper bound we derived. Our results hint rules for designing
IRS-aided communication systems and allow to draw conclusions on the trade-off
between performance and complexity required for configuring the IRS.
