S. Keyrouz, D. Caratelli, and D. Favreau
The development of 5G technologies aimed at increasing data rate of wireless communication networks by a factor of 100 imposes stringent specifications (large bandwidth, high gain, small size and temperature independent performance) on the design of the radio frequency (RF) electronics. Various front-end antenna solutions relying on patch radiating structures have been proposed for millimeter-wave applications. Said antennas are characterized by small size, low weight, and low cost and can be easily integrated on chip. However, because of losses in conductors as well as dielectric substrate materials, these antennas suffer from very low radiation efficiency (< 10 %), low gain (< 0 dBi), and narrowband behavior.