The demand for broadband content and services in both wired and wireless technologies has been growing at tremendous rates, and predictions indicate that wireless data-rates of multiple tens of Gbps will be required by the year 2020, essentially for short-range connectivity. Currently available wireless technology cannot support these future demands, and so there is an urgent need to develop new technology platforms as articulated in the H2020 “ICT6 – smart optical and wireless network technologies” call, that should be cost and energy efficient to enable ubiquitous ultra-broadband wireless communications seamlessly integrated with high-speed fibre-optic networks, paving the way for 100 Gbps datarates in the long term. The frequency spectrum currently in use is not expected to be suitable to accommodate the predicted future data-rate requirements, in spite of the significant and continuous progress that has been achieved in spectral efficiency techniques, and therefore there is a need to embrace higher frequency bands, namely in the mm-wave and THz bands, above 60 GHz and up to 1 THz.