The rapid growth of mobile data traffic and the use of smartphone or others connected objects have recently drawn increased attention to the large amount of underutilized millimetre wave (mmWave) frequency bands (30 – 300 GHz) as a potential solution to achieve tens or hundreds of times more capacity compared to the current cellular networks. In this scenario, 5G wireless heterogeneous networks will be probably composed of medium-range macro-cells at sub-3 GHz bands, small-cells at sub-6 GHz, and small-cells at mmWave bands (28, 38, 60 GHz or E band 71 – 76 and 81 – 86 GHz) with a target peak capacity of 2 – 7 Gb/s near the access point. High-capacity (peak capacity around 10 – 25 Gb/s) mmWave backhaul links working in line-of-sight (LOS) conditions will also connect the access points to the core network. This high-capacity backhaul link offers operators multihop short- and medium-range links in the range of hundreds of meters to 1 km. Currently, three frequency bands are considered for mmWave backhauling: (i) the 28 GHz band, (ii) the V-band (57 – 66 GHz), and the (iii) E-band. High-gain fixed-beam or electronically steerable antennas are required to implement 5G backhauling.
In this context, several antennas architectures, based on phased arrays or spatial feeding arrays, have been developed and demonstrated at CEA-Leti for short-, medium-, and long-range mmWave communications in the band 30 – 170 GHz. Several fully integrated mmW modules front-ends or sub-modules based on different packaging technologies have also been demonstrated at 60, 140 and 30 GHz. The results of the optimization, simulation, and characterization of the different antenna architectures will be detailed in this presentation. Conclusions on future challenges and roadmaps will be drown.